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NATIONAL BUILDING CODE
OF INDIA 2016
> VOLUME 2 V
-
About the book
With the objective of finding out areas of
economies in construction costs, the Planning
Commission had set up a Panel of Experts in
1965 to study in depth the whole gamut of
construction activities. The outlay on
construction works and particularly on building
forms a very large portion of the national
investment. One of the facets of building
construction, namely, controlling and regulating
buildings through municipal byelaws and
departmental handbooks received the attention
of the Panel and a study of these regulatory
practices revealed that some of the prevailing
methods of construction were outmoded; some
designs were overburdened with safety factors
and there were other design criteria which, in
the light of newer techniques and
methodologies, could be rationalized; and
building byelaws and regulations of municipal
bodies which largely regulate the building
activity in the country wherever they exist, were
outdated. They did not cater to the use of new
building materials and the latest developments
in building designs and construction
techniques, it also became clear that these
codes and byelaws lacked uniformity and they
were more often than not 'specification
oriented' and not 'performance oriented'
thereby hindering the use of modern
techniques and also restricting the creative
faculties of architects, engineers and structural
engineers.
The studies of the Panel led to the conclusion
that a unified building code at the national level
should be formulated reflecting the latest trends
in building construction activity. At the
suggestion of the Planning Commission, this
task was taken up by the then Indian Standards
Institution (now Bureau of Indian Standards),
and its Guiding Committee finalized the Code to
serve as guide to all governmental and private
agencies controlling building activities. In
preparing the Code expertise was drawn upon
from all over the country - the central and state
governments, local bodies, professional
institutions and private agencies.
(Continued on flap 2)
PRICE ? 13,760.00
(Vol. 1 & 2)
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2
NATIONAL BUILDING CODE
OF INDIA 2016
VOLUME 2
nmcb ^JTt
BUREAU OF INDIAN STANDARDS
SP 7 : 2016
FIRST PUBLISHED 1970
FIRST REVISION 1983
SECOND REVISION 2005
THIRD REVISION 2016
© BUREAU OF INDIAN STANDARDS
ICS 01.120; 91.040.01
PRICE ? 13,760.00
(Vol. 1 & 2)
PUBLISHED BY BUREAU OF INDIAN STANDARDS, MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR
MARG, NEW DELHI 110002; TYPESET AT SUNSHINE GRAPHICS, 263, TELIWARA, SHAHDARA, DELHI
110032; PRINTED AT J. J. OFFSET PRINTERS, A-24, SECTOR 68, NOIDA, GAUTAM BUDH NAGAR,
UTTAR PRADESH (INDIA).
CONTENTS
Volume 1
Foreword ... (v)
Committee Composition ... (ix)
Important Explanatory Note for Users of the Code ... (xxx)
Information for the Users about Availability of the Code in Groups ... (xxxi)
Total Pages
Part 0 Integrated Approach — Prerequisite for Applying Provisions of the Code ... 12
Part 1 Definitions ... 28
Part 2 Administration ... 32
Part 3 Development Control Rules and General Building Requirements ... 150
Part 4 Fire and Life Safety ... 116
Part 5 Building Materials ... 46
Part 6 Structural Design
Section 1 Loads, Forces and Effects ... 134
Section 2 Soils and Foundations ... 60
Section 3 Timber and Bamboo
3A Timber ... 56
3B Bamboo ... 30
Section 4 Masonry ... 86
Section 5 Concrete
5A Plain and Reinforced Concrete ... 118
5B Prestressed Concrete ... 52
Section 6 Steel ... 138
Section 7 Prefabrication, Systems Building and Mixed/Composite Construction
7 A Prefabricated Concrete ... 42
7B Systems Building and Mixed/Composite Construction ... 12
Section 8 Glass and Glazing ... 80
Volume 2
Important Explanatory Note for Users of the Code ... (iv)
Information for the Users about Availability of the Code in Groups ... (v)
Total Pages
Part 7 Construction Management, Practices and Safety ... 76
Part 8 Building Services
Section 1 Lighting and Natural Ventilation ... 56
Section 2 Electrical and Allied Installations ... 172
Section 3 Air Conditioning, Heating and Mechanical Ventilation ... 86
Section 4 Acoustics, Sound Insulation and Noise Control ... 46
Section 5 Installation of Lifts, Escalators and Moving Walks
5A Lifts ... 96
5B Escalators and Moving Walks ... 44
Section 6 Information and Communication Enabled Installations ... 28
Part 9 Plumbing Services (Including Solid Waste Management)
Section 1 Water Supply ... 44
Section 2 Drainage and Sanitation ... 82
Section 3 Solid Waste Management ... 16
Section 4 Gas Supply ... 18
Part 1 0 Landscape Development, Signs and Outdoor Display Structures
Section 1 Landscape Planning, Design and Development ... 34
Section 2 Signs and Outdoor Display Structures ... 24
Part 11 Approach to Sustainability ... 98
Part 12 Asset and Facility Management ... 98
(hi)
Important Explanatory Note for Users of the Code
In any Part/Section of this Code, where reference is made to ‘good practice’ in
relation to design, constructional procedures or other related information, and where
reference is made to ‘accepted standard’ in relation to material specification,
testing, or other related information, the Indian Standards listed at the end of the
Part/Section shall be used as a guide to the interpretation.
At the time of publication, the editions indicated in the standards were valid. All
standards are subject to revision and parties to agreements based on any Part /
Section are encouraged to investigate the possibility of applying the most recent
editions of the standards.
In the list of standards given at the end of a Part/Section, the number appearing
within parentheses in the first column indicates the number of the reference of the
standard in the Part/Section. For example:
a) Good practice [7(2)] refers to the Indian Standard given at serial number (2)
of the list of standards given at the end of Part 7, that is, IS 16416 : 2016
‘Construction project management: Project formulation and appraisal —
Guidelines’.
b) Good practice [8-1(6)] refers to the Indian Standard given at serial number
(6) of the list of standards given at the end of Section 1 of Part 8, that is,
IS 3362 : 1977 ‘Code of practice for natural ventilation of residential buildings
(first revision)'.
c) Good practice [8-3(1 6)] refers to the Indian Standard given at serial number
(16) of the list of standards given at the end of Section 3 of Part 8, that is,
IS 483 1 : 1968 ‘Recommendation on units and symbols for refrigeration’.
d) Accepted standard [8-5A(6)] refers to the Indian Standard given at serial
number (6) of the list of standards given at the end of Subsection 5A of
Part 8, that is, IS 14665 (Part 3/Sec 1 and 2) : 2000 ‘Electric traction lifts:
Part 3 Safety rules. Section 1 Passenger and goods lifts, Section 2 Service
lifts’.
e) Accepted standards [8-6(2)] refers to the Indian Standards given at serial
number (2) of the list of standards given at the end of Section 6 of Part 8,
that is, IS 9537 (Part 3) : 1983 ‘Specification for conduits for electrical
installations: Part 3 Rigid plain conduits for insulating materials’ and
IS 3419 : 1989 ‘Specification for fittings for rigid non-metallic conduits
(second revision)' .
f) Accepted standard [9-1(1)] refers to the Indian Standard given at serial
number (1) of the list of standards given at the end of Section 1 of Part 9.
that is, IS 10446 : 1983 ‘Glossary of terms relating to water supply and
sanitation’.
(w)
INFORMATION FOR THE USERS ABOUT AVAILABILITY OF
THE CODE IN GROUPS
For the convenience of the users, the National Building Code of India 2016 is available as a comprehensive
volume as well as in the following five groups, each incorporating the related Parts/Sections dealing with particular
area of building activity:
Group 1
For Development/
Part 0
Integrated Approach — Prerequisite for Applying Provisions of the Code
Building Planning
Part 1
Definitions
and Related
Part 2
Administration
Aspects
Part 3
Development Control Rules and General Building Requirements
Part 4
Fire and Life Safety
Part 5
Building Materials
Part 10
Landscape Development, Signs And Outdoor Display Structures
Section 1
Landscape Planning, Design and Development
Section 2
Signs and Outdoor Display Structures
Part 1 1
Approach to Sustainability
Group 2
For Structural
Part 0
Integrated Approach — Prerequisite for Applying Provisions of the Code
Design and Related
Part 6
Structural Design
Aspects
Section 1
Loads, Forces and Effects
Section 2
Soils and Foundations
Section 3
Timber and Bamboo
3A Timber
3B Bamboo
Section 4
Masonry
Section 5
Concrete
5A Plain and Reinforced Concrete
5B Prestressed Concrete
Section 6
Steel
Section 7
Prefabrication, Systems Building and Mixed/ Composite
Construction
7A Prefabricated Concrete
7B Systems Building and Mixed/ Composite Construction
Section 8
Glass and Glazing
Part 1 1
Approach to Sustainability
Group 3
For Aspects
Part 0
Integrated Approach — Prerequisite for Applying Provisions of the Code
Relating to
Part 7
Construction Management, Practices and Safety
Construction, and
Part ! 1
Approach to Sustainability
Asset/ Facility
Part 12
Asset and Facility Management
Management
Group 4
For Aspects
Part 0
Integrated Approach — Prerequisite for Applying Provisions of the Code
Relating to Building
Part 8
Building Services
Services
Section 1
Lighting and Natural Ventilation
Section 2
Electrical and Allied Installations
Section 3
Air Conditioning, Heating and Mechanical Ventilation
Section 4
Acoustics, Sound Insulation and Noise Control
Section 5
Installation of Lifts, Escalators and Moving Walks
5A Lifts
5B Escalators and Moving Walks
Section 6
Information and Communication Enabled Installations
Part 1 1
Approach to Sustainability
Group 5
For Aspects
Part 0
Integrated Approach — Prerequisite for Applying Provisions of the Code
Relating to
Part 9
Plumbing Services (including Solid Waste Management)
Plumbing Services
Section 1
Water Supply
and Solid Waste
Section 2
Drainage and Sanitation
Management
Section 3
Solid Waste Management
Section 4
Gas Supply
Part 11
Approach to Sustainability
The information contained in different groups will serve the concerned professionals dealing with the respective
areas. However, it is advisable that professionals essentially dealing with any of the above groups should also
refer the other groups.
(v)
'
NATIONAL BUILDING CODE OF INDIA
PART 7 CONSTRUCTION MANAGEMENT, PRACTICES AND SAFETY
BUREAU OF INDIAN STANDARDS
CONTENTS
FOREWORD 3
1 SCOPE ••• 7
2 TERMINOLOGY ... 7
3 GENERAL ... 7
SECTION 1 CONSTRUCTION MANAGEMENT
4 CONSTRUCTION PROJECT MANAGEMENT ... 8
SECTION 2 CONSTRUCTION PLANNING AND SITE MANAGEMENT
5 PLANNING ASPECTS ... 17
SECTION 3 CONSTRUCTION PRACTICES
6 CONSTRUCTION CONTROL AND PRACTICES ... 19
7 TEMPORARY WORKS ... 21
8 STORAGE, STACKING AND HANDLING PRACTICES ... 23
SECTION 4 SAFETY IN CONSTRUCTION
9 SAFETY IN CONSTRUCTION OF ELEMENTS OF A BUILDING ... 34
1 0 SAFETY IN DEMOLITION OF BUILDINGS ... 52
SECTION 5 REPAIRS, RETROFITTING AND STRENGTHENING OF BUILDINGS
11 MAINTENANCE MANAGEMENT ... 57
12 PREVENTION OF CRACKS ...57
1 3 REPAIRS AND SEISMIC STRENGTHENING OF BUILDINGS ... 58
SECTION 6 HABITAT AND WELFARE REQUIREMENTS FOR WORKERS
14 HABITAT AND OTHER WELFARE REQUIREMENTS FOR CONSTRUCTION ... 59
WORKERS
ANNEX A CHECK LIST FOR STACKING AND STORAGE OF MATERIALS ... 63
LIST OF STANDARDS ... 64
2
NATIONAL BUILDING CODE OF INDIA 2016
National Building Code Sectional Committee, CED 46
FOREWORD
This Code (Part 7) covers construction project management; construction planning, site management and building
construction practices; storage, stacking and handling of materials; and safety of personnel during construction
operations for all elements of a building and demolition of buildings; and habitat and welfare requirements for
workers. It also covers guidelines relating to repairs, retrofitting and strengthening of buildings.
The principles enunciated in the various sections of this Part are to be ultimately utilized and implemented in the
physical construction of the buildings with the required infrastructure. This would require sound construction
practices and efficient management thereof in order to ensure that the implementation of the project is carried out
within the estimated cost and planned period to the required quality standards and in a safe and sustainable
manner. Workers in large number, both skilled and unskilled, are engaged in the innumerable construction works.
Due to increased tempo of such a building activity and large scale mechanization, hazards of accidents could
increase considerably. It is, therefore, imperative that adequate safety rules are laid down for every phase of
construction work. It is also important to give due cognizance to habitat and welfare requirements of workers at
construction site. This Part also deals with these aspects.
Planning the various construction operations before hand and making adequate arrangements for procurement
and storage of materials, and the machinery to get work done is as important as carrying out these construction
operations in accordance with good practice. Lack of planning or defective planning may result in avoidable
delay in the completion of work and consequently increased hazards from the point of view of fire, health and
structural soundness. This Part covers provisions in this regard.
A construction project is an endeavour undertaken by a project team on behalf of owner/client to create a built
facility suited to the defined functional objectives. From inception to commissioning, the project goes through
various distinct stages leading to progressive achievement of project objectives. Each stage involves specific
inputs, processes (both technical and managerial) and deliverables. Typically, the life cycle of a project from
commencement to completion involves the following stages:
a) Project formulation and appraisal — Inception, feasibility and strategic planning;
b) Project development — Project brief development, planning and design, finalization of proposals,
procurement strategy, construction documentation including tender drawings, working drawings,
specifications, cost estimates, bills of quantities, procurement documents;
c) Planning for construction — Sequencing of project components, planning tools, resource planning and
time cost trade off;
d) Tender action — Open competitive bidding/pre-qualification of agencies, issue of tender documents,
evaluation of bids, negotiation if required and award of work;
e) Construction — Execution, monitoring, control, work acceptance; and
f) Commissioning and handing over — Contractual closeout, financial closeout, defect liability
commencement, facility handing over.
The distinct features of a construction project include the temporary nature of the organizations involved, the
evolutionary process of project deliverables during project development stages and the unique output of the built
facility. As a result of these features, unless there is efficient and effective project management, a construction
project is faced with challenges of uncertainties leading to time over-runs, cost over-runs, changes in project
parameters, loss of quality and inability to meet the functional objectives. While technical soundness of a proposal
is an important aspect of a construction project, the management aspects, which involve techno-legal, financial
and other issues, have also a significant role in the success of a project. Therefore, management functions and
technical processes in a construction project need to be integrated towards achieving project objectives. Top
management commitment plays an important role in harmoniously achieving these project objectives. In some of
the public sector projects, it may be necessary to share relevant information with public at large through appropriate
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
3
means. The overall management of a building construction project is very important to ensure that the objectives
of such a project are achieved through scope management, procurement management, time management, cost
management, quality management, risk management, communication management, human resources management,
safety, health and environment management and integration management. This Part, therefore, gives guidelines
on these areas.
The first version of this Part was formulated in 1970, which was subsequently revised in 1983 and 2005. In the
first revision, information regarding handling operations that is unloading, stacking, lifting, loading and conveying
of building materials, was also given along with the storage practices. Additional information regarding the use of
ladders; safety requirements for floor and wall openings, railings and toe boards; piling and other deep foundations;
constructions involving use of hot bituminous materials; and erection of structural steel work and concrete framed
structures, etc, were included.
In the second revision, the Section 1 ‘Construction Practices’ of this Part, had been revamped to include the
planning and management aspects. Further, provisions on construction using bamboo were also incorporated. The
other important modifications incorporated in the second revision included comprehensive updating of the
provisions with regard to stacking and storage of building materials and components, which were comprehensively
covered in line with the revised IS 4082 : 1996 ‘Recommendations on stacking and storage of construction
materials and components at site ( second revision)'-, addition of provisions of safety requirements of hoists/lifts
for worker during construction; incorporation of aspects like preventive measures such as falling material hazards
prevention, fall prevention, disposal of debris, fire protection, etc, with regard to safety at work site; addition of
provisions regarding safety management at work sites; addition of a new section on ‘Maintenance management,
repairs, retrofitting and strengthening of buildings’, covering aspects like maintenance management, prevention
of cracks, and repairs and seismic strengthening of buildings; and updating of safety provisions with respect to
demolition of buildings.
As a result of experience gained in implementation of 2005 version of this Part and feedback received as well as
in view of formulation of new standards in the field of construction project management and construction practices
and revision of some existing standards, including those on safety, a need to revise this Part was felt. This revision
has, therefore, been prepared to take care of these aspects. This Part has been divided into six sections as follows,
under which all technical provisions relating to their subject areas, have been given:
Section 1 Construction Management
Section 2 Construction Planning and Site Management
Section 3 Construction Practices
Section 4 Safety in Construction
Section 5 Repairs, Retrofitting and Strengthening of Buildings
Section 6 Habitat and Welfare Requirements for Workers
The significant changes incorporated in this revision include:
a) This Part has been divided into six Sections under which the provisions have been rearranged in a logical
sequence;
b) Provisions on construction project management have been detailed which also now includes project
formulation and appraisal.
c) Safety provisions with respect to scaffolding, piling and other deep foundations, blasting and related
drilling operations, and construction involving use of hot bituminous materials have been updated;
d) A new clause on habitat and other welfare requirements for construction workers has been introduced;
e) A new clause on urban/city roads planning and construction, has been added;
f) A new clause on temporary works has been included;
g) Provisions on construction using bamboo has been shifted to Part 6 ‘Structural Design, Section 3B
Bamboo, and a reference to the same has been given in this Part;
h) Provisions on maintenance management has been shifted to Part 12 ‘Asset and Facility Management’ of
the Code and a reference to the same has been given in this Part; and
j) References to all the concerned Indian Standards have been updated.
Users are encouraged to employ suitable construction management software as an aid to implement provisions of
4
NATIONAL BUILDING CODE OF INDIA 2016
this Code. The guidelines may be applicable in general to all construction projects. However, for smaller projects,
the applicability of various provisions may be decided appropriately by the parties concerned.
Provisions on sustainable building construction practices are covered in Part 11 ‘Approach to Sustainability’ of
the Code.
The information contained in this Part is largely based on the following Indian Standards and Special Publications:
IS 3696
(Part 1)
: 1987
(Part 2)
: 1991
IS 3764 :
1992
IS 4082 :
1996
IS 4130 :
1991
IS 4912 :
1978
IS 5121 :
2013
IS 5916 :
2013
IS 7205 :
1974
IS 7969 :
1975
IS 8989 :
1978
IS 13415
: 1992
IS 13416
(Part 1)
: 1992
(Part 2)
: 1992
(Part 3)
: 1994
(Part 4)
: 1994
(Part 5)
: 1994
IS 13430 :
: 1992
Safety code for scaffolds and ladders:
Scaffolds
Ladders
Code of practice for excavation work {first revision )
Recommendations on stacking and storage of construction materials and components at
site {second revision )
Safety code for demolition of buildings {second revision)
Safety requirements for floor and wall openings, railing and toe boards (first revision )
Code of safety for piling and other deep foundations {first revision)
Safety code for construction involving use of hot bituminous materials {first revision)
Safety code for erection of structural steel work
Safety code for handling and storage of building materials
Safety code for erection of concrete framed structures
Safety code for protective barrier in and around buildings
Recommendations for preventive measures against hazards at work places:
Falling material hazards prevention
Fall prevention
Disposal of debris
Timber structures
Fire protection
Code of practice for safety during additional construction and alteration to existing
buildings
IS 15883 (Part 1) : Guidelines for construction project management: Part 1 General
2009
IS 16601 : 2016 Guidelines for habitat and welfare requirements for construction workers
A reference to SP 62 : 1992 ‘Handbook on building construction practices (excluding electrical works)’ and
SP 70 : 2001 ‘Handbook on construction safety practices’, may also be made.
All standards, whether given herein above or cross-referred to in the main text of this Part, are subject to revision.
The parties to agreement based on this Part are encouraged to investigate the possibility of applying the most
recent editions of the standards.
For the purpose of deciding whether a particular requirement of this Code is complied with, the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1 960
‘Rules for rounding off numerical values (revised)' . The number of significant places retained in the rounded off
value should be the same as that of the specified value in this Part.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
5
-
NATIONAL BUILDING CODE OF INDIA
PART 7 CONSTRUCTION MANAGEMENT, PRACTICES AND SAFETY
1 SCOPE
1.1 This Code (Part 7) covers construction project
management; construction planning, site management
and building construction practices; storage, stacking
and handling of materials; and safety of personnel
during construction operations for all elements of a
building and demolition of buildings; and habitat and
welfare requirements for workers. It also covers
guidelines relating to repairs, retrofitting and
strengthening of buildings.
1.2 The provisions in respect of sustainable building
construction practices are covered in Part 1 1 ‘Approach
to Sustainability’ of the Code which shall be used in
conjunction with this Part.
1.3 Provisions relating to maintenance management are
covered in Part 12 ‘Asset and Facility Management’ of
the Code which has been referred to in this Part.
2 TERMINOLOGY
For the purpose of this Part, the following definitions
shall apply, and for other terms those given in the
accepted standards [7(1)] shall apply.
2.1 Anthority Having Jurisdiction
The authority which has been created by a statute and
which for the purpose of administering the Code/Part,
may authorize a committee or an official to act on its
behalf; hereinafter called the ‘Authority’.
2.2 Definitions Relating to Safety in Construction
2.2.1 Construction Equipment — All equipment,
machinery, tools and temporary retaining structures and
working platforms, that is, tools, derricks, staging,
scaffolds, runways, ladders and all material, handling
equipment including safety devices.
2.2.2 Floor Hole — An opening measuring less than
300 mm but more than 25 mm in its least dimension, in
any floor, platform, pavement, or yard, through which
materials but not persons may fall; such as, a belt hole,
pipe opening or slot opening.
2.2.3 Floor Opening — An opening measuring 300 mm
or more in its least dimension, in any floor, platform,
pavement or yard through which person may fall; such
as hatch way, stair or ladder opening, pit or large
manhole.
2.2.4 Guard Railing — A barrier erected along exposed
edges of an open side floor opening, wall opening,
ramp, platform, or catwalk or balcony, etc, to prevent
fall of persons.
2.2.5 Materials Handling Hoists — A platfonn, bucket
or similar enclosure exclusively meant for the lifting
or lowering of construction material, the hoists being
operated from a point outside the conveyance.
2.2.6 Pile Rig — The complete pile driving equipment
comprising piling frame, leader, hammer, extractor
winch and power unit. Complete pile driving rig may
be mounted on rafts or pontoon or rails. Pile rig may
also be a mobile unit mounted on trailers or trucks, or
a special full revolving rig for raking piles.
2.2.7 Platform — A working space for persons, elevated
above the surrounding floor or ground, such as balcony
or platform for the operation of machinery and
equipment.
2.2.8 Scaffold — A temporary structure consisting of
standards, putlogs, ledgers, generally of bamboo,
Bailies, timber or metal to provide a working platform
for workers and materials in the course of construction,
maintenance, repairs and demolition, and also to
support or allow hoisting and lowering of workers, their
tools and materials.
2.2.9 Toe Board — A vertical barrier erected along
exposed edge of a floor opening, wall opening,
platform, catwalk or ramp to prevent fall of materials
or persons.
2.2.10 Wall Hole — An opening in any wall or partition
having height of less than 750 mm but more than 25 mm
and width unrestricted.
2.2.11 Wall Opening — An opening in any wall or
partition having both height of at least 750 mm and
width of at least 450 mm.
3 GENERAL
3.1 A general overview of construction project
management and information regarding the applicable
tools and techniques are covered in Section 1
‘Construction Management’ of this Part, which also
demarcates various stages of a construction project and
activities thereunder. Section 1 gives brief guidelines
on project formulation and appraisal, and various
construction project management functions; and for
detailed guidelines on each of these, gives reference to
the available good practices.
Construction planning and site management, plays an
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
7
important role in smooth progress of a building
construction activity and are covered in Section 2
‘Construction Planning and Site Management’. The
knowledge of actual technical provisions in regard to
practices relating to various building components
starting from sub-structure to super-structure, play a
key role in achieving the quality of building
construction. Also, temporary enabling works; proper
stacking and storage of materials; and well planned
handling operations, have important role in proper, safe
and smooth progress in construction work at site. The
provisions in respect of these are covered in Section 3
‘Construction Practices’.
The objectives of sound construction of buildings
having requisite quality, durability and finish has to be
duly dovetailed with the goals of safety whether during
construction of a new building or addition/alteration
to an existing building part thereof or during demolition
of an existing building. Section 4 ‘Safety in
Construction’ covers provisions to these effects.
Section 5 ‘Repairs, Retrofitting and Strengthening of
Buildings’ covers repair, retrofitting and strengthening
of existing buildings and Section 6 ‘Habitat and Welfare
Requirements for Workers’ deals with habitat and other
welfare requirements for construction workers at site.
3.2 The objective of universal design and accessibility
is to ensure that all users, including those with
disabilities and elderly people are able to access all the
facilities within the built environment including in the
public buildings, on an equal basis. Requirements for
accessibility in built environment for the elderly and
for persons with disabilities as given in 13 of Part 3
‘Development Control Rules and General Building
Requirements’ of the Code shall be complied with at
all stages of the construction project.
SECTION 1 CONSTRUCTION
MANAGEMENT
4 CONSTRUCTION PROJECT MANAGEMENT
4.1 General
4.1.1 A project is generally a non-recurring task having
a definable beginning and end, with a definite mission
and has a set of objectives and achievements. Project
management is application of knowledge, skills, tools
and techniques to achieve the objectives of a defined
project with the aim to ensure that a project is completed
within the scheduled time, authorized cost and to the
requirement of quality standards. Construction project
management refers to such project management when
applied to construction of built facility. Project
objectives depend on the requirements of the built
facility. From the point of view of construction project
management, project objectives may be defined in
terms of scope, time, cost and quality. This may usually
take place in project appraisal stage and shall be done
in accordance with the good practice [7(2)].
Information and guidelines given under 4.1.2 to 4.1.6
shall be appropriately utilized under different stages
of construction project.
4.1.2 Stakeholder
Stakeholder is a person, group of persons or
organizations who are actively involved in the project
or those who have an interest in the success of a project
and its environment. Generally in a construction project,
besides the owner/client, the project manager,
consultants, construction agencies and the users are the
stakeholders. In addition, depending on the nature of
the project, there may be other stakeholders such as
financer, government and public at large.
4.1.3 Construction Project Life Cycle
Construction project life cycle consists of project
formulation and appraisal, project development,
planning for construction, tender action, construction,
and commissioning and handing over, as main stages.
These stages involve defined decisions, deliverables
and completion of mile-stones for control of project,
ensuring that the adverse impact of uncertainties is
overcome at each stage in the progress. Accordingly,
the responsibilities of project team should be defined
and measured for acceptance, and liabilities determined
objectively.
Project objectives, drawn out of feasibility established
in the appraisal stage, are achieved progressively
through each of the project life cycle stages. The stage-
wise break-up of project objectives, tasks, compliance
and authorization to proceed further in the next stage
should be structured comprehensively through various
stages of life cycle. Each stage of construction project
life cycle may be considered as a subproject, thus
making overall complexities of a project more
manageable.
A typical construction project life cycle is given in
Fig. 1.
4.1.4 Construction Project Delivery Models
Project delivery model determines the manner in which
the project is planned, designed, executed and contract
administration carried out. It also determines the
contractual relationships between the owner/client,
design consultants and construction agency. The
delivery model shall define the span of control and role
and responsibilities of each of the above parties. The
main types of project delivery models that are in vogue
in construction projects are: (a) Traditional design-bid-
build, (b) Design-build with variants, (c) Turn-key and
(d) Build, operate and transfer and its variants. Each
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NATIONAL BUILDING CODE OF INDIA 2016
TIME - -
Fig. 1 Typical Construction Project Life Cycle
of the delivery models can adopt different types of
contracts depending upon the suitability of the contract
type in relation to the nature and type of projects,
project objectives and other project specific
considerations.
4.1.5 Construction Methodologies and Techniques
Suitable construction methodologies and techniques,
such as, conventional, prefabrication, systems building
approach, mixed/composite construction, mechanization
in construction and other innovative technologies, shall
be defined considering design principles adopted and
also considering the project objectives in terms of factors,
like, scope, time, cost and quality requirements. Method
statement may be made for all critical items of work.
4.1.6 Organizational Structures
Organizational structure depends on the project delivery
model. As an example, a typical organization chart for
Design-Bid-Build model is given in Fig. 2.
4. 1.6.1 Construction project tnanagement
organizational teams
For any given project delivery model, an appropriate
organizational structure shall be selected so as to facilitate
constitution of teams across various agencies involved.
Such teams are fundamental functional units generally
specific to each of the life cycle stages of a project.
Health, Safety and Environment (HSE) and quality set
up shall directly report to the Project Manager.
4.2 Stages of a Construction Project
4.2.1 Typically a construction project (whether small
or large) may be considered to involve the following
distinct broad stages:
a) Project formulation and appraisal stage:
1) Inception,
2) Feasibility, and
3) Strategic planning.
b) Pre-construction stage:
1) Project development,
2) Planning for construction, and
3) Tender action.
c) Construction stage, and
d) Commissioning and handing over stage.
4.2.2 Project Formulation and Appraisal Stage
For successful management of construction projects,
the earlier stages when the construction project is
conceived, formulated and its feasibility assessed,
leading to decision to implement the project, are equally
important. The guidelines given in the good practice
[7(2)] should be employed during project formulation
and appraisal stage of a construction project.
NOTE — This stage of a construction project is basically the
preliminary stage covering activities up to the stage of
preparation of proposals for obtaining approval for
implementing the project including financial approval and
includes inception, pre-feasibility, feasibility, related project
strategic planning and viability assessment and review prior to
approval of project.
For all other above stages, the relevant construction
management function guidelines given in 4.3 should
be employed for achieving the intended objectives.
4.2.3 Pre-Construction
4.2.3. 1 Project development
This shall involve the following:
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
9
NOTE — 'Consultants’ may cover in-house teams or outside consultants.
Fig. 2 Typical Organization Structure for Design-Bid-Build Model
a) Formalization of design brief;
b) Site survey and soil investigation;
c) Hazard risk vulnerability analysis;
d) Alternative concept designs with costing and
finalization;
e) Preliminary designs and drawings;
f) Development of design of each discipline and
their integration;
g) Obtaining statutory approvals;
h) Selection of construction methodology;
j) Preliminary cost estimates;
k) Detailed planning and design of each
discipline;
m) Construction working drawings and related
specifications with integration of engineering
inputs of all concerned disciplines;
n) Detailed cost estimates;
p) Detailed specifications and oills of quantities;
and
q) Tender documents.
Peer review proof checking of the drawings, designs
estimates shall be done in case of important projects,
depending upon their complexity and sensitivity.
Environment impact analysis and social impact analysis
shall be done in applicable cases.
4.2.3. 2 Planning for construction
The following aspects shall be considered:
a) Sequencing of project components,
b) Planning tools:
1 ) Work breakdown structures (WBS).
2) Bar charts, and
3) Network techniques and scheduling.
c) Resource planning, and
d) Time cost trade off.
4. 2. 3. 2.1 Sequencing of project components
Methodology of construction shall be detailed before
the start of the project. Sequencing of project
components shall be done on the basis of methodology
adopted and availability of resources. This shall be
reviewed during the progress of the project and revised,
if necessary.
4.2.3. 2. 2 Planning tools
The planning tools described below may be employed
for effective management of a construction project:
a) Work breakdown structure (WBS) — The
WBS shall identify the total scope of works
involved in the project and shall form the basis
for the development of detailed project
schedule. Through WBS, the project shall be
subdivided into major subdivisions (work
packages) and each major subdivision shall
be further subdivided into additional levels as
required up to the level of activities that could
form the basis for monitoring and control of
project performance in terms of time, cost and
quality parameters. WBS shall provide activity
listing with associated cost account codes for
the preparation of project schedule either by
bar charts or by network diagramming
methods.
b) Bar chart — Bar chart is the simplest form of
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project scheduling and used for small and
complex projects and in preliminary planning
and tender-stages of major projects. A typical
bar chart form of project schedule depicts the
various activities on a calendar time scale in
the form of bars in their relative positions with
start and finish dates and length of bar
indicating probable activity duration. Linked
bars represent the interdependencies between
the activities. Bar chart type of schedule shall
be used to comprehend, summarize and
display the results of complex project network
analysis and further monitoring and
controlling process.
c) Network techniques and scheduling
1) Network diagramming methods —
Network based project schedule shall be
used for major and complex projects. In
this method, the network of project
activities identified through WBS is
developed incorporating their logical
relationships and interdependencies. The
two available approaches for network
diagramming techniques are arrow
diagramming method (ADM) and
precedence diagramming method (PDM).
2) Network analysis and scheduling — The
project network incorporating the activity
durations and logical relationships shall
be analyzed with forward and backward
pass schedule calculations to establish
early and late start and finish time of
activities with their available floats,
critical activities, critical path and overall
project duration. The project schedule is
prepared in terms of calendar dates of
start and finish of activities with available
floats. The network schedule shall also
be presented in the form of linked bar
chart or in tabular format.
For details on network preparation and
analysis, reference shall be made to good
practices [7(3)]. Network schedule shall be
prepared for all disciplines and they shall be
integrated into a master control schedule.
4.2.3.2.3 Resource planning
This shall involve the following:
a) Resource allocation — The feasibility of the
network shall be checked with respect to
manpower, equipment, materials, other
resources required at the site.
b) Resource levelling — It shall be done by re¬
allocating the slack resources from non-
critical path to critical path activity in order
to obtain a reduction of time or by shifting
the activities within the floats available with
them, to obtain optimum uniform resource
requirements.
c) Resource schedule — Schedule of following
resource requirements with respect to time
shall be prepared on the basis of network
developed and kept in the database for project
control purposes:
1 ) Technology,
2) Manpower:
i) Technical staff,
ii) Skilled labour,
iii) Unskilled labour,
3) Machinery,
4) Materials, and
5) Cash flow.
Resource schedule shall be prepared separately for
client, consultant and construction agency.
4.2.3.2.4 Time cost trade off
Time cost trade off analysis shall be done to obtain a
minimum total cost of the project within the specified
time. This shall be done taking into consideration direct
cost and indirect cost of the project.
4.2.3.3 Tender action
4.2.3.3.1 Preparation of tender documents
The bill of quantities, specifications, drawings and
conditions of contract should be prepared on the basis
of design and details finalized in project proposal
development stage (see 4.2.3. 1) keeping in view the
construction project delivery model selected. The
format, terminologies and terms and conditions should
be as per the standard engineering practices. In case of
any special item or condition, the same shall be
described clearly to avoid any ambiguity.
4.2.3.3.2 Selection of construction agency
Selection of construction agency shall be done by either:
a) Open competitive bidding — In this case,
tender notice should be publicized adequately
to obtain competitive tenders from competent
agencies for the project; or
NOTE — Electronic tendering could also be considered.
b) Limited competitive bidding — In large,
specialized and important works,
prequalification of contractors shall be done
considering their financial capability, bid
capacity, experience of similar type of works,
past performance, technical staff, and plants
and machinery available.
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4.2.3.3.3 Bid evaluation, negotiation and award of
work
After due evaluation and negotiation with the bidders,
if required, the work shall be awarded to the
construction agency based on competitive technical and
financial bids.
4.2.4 Construction
This is one of the most important stages of construction
management where pre-construction stage outputs are
realized into physical tangible form within the
constraints of time and cost. The intent or need for
functional and physical characteristics, defined in the
pre-construction stage outputs through specifications,
drawings and consolidated project brief is realized
through various construction project management
functions described in 4.3 and particularly through
procurement management, time management, cost
management, quality management and health, safety
and environment management.
4.2.5 Commissioning and Handing Over
After all construction activities of the project are
complete as per specifications and designs, project
commissioning and handing over stage follows. It shall
need the compliance of the following:
a) Clearing of site,
b) Removal of all defects at the time of
completion and during defect liability period,
c) Preparation of list of inventories,
d) Certification and settlement of construction
agency’s final bills for payment,
e) Obtaining completion certificate from local
government bodies/departments,
f) Preparation of maintenance manual,
g) Performance compliance verification of built
facility,
h) Handing over all other required documents,
including guarantees, to the client/owner,
j) Restoration of surroundings, and
k) Preparation and handing over all as-built
drawings.
4.3 Construction Project Management Functions
Construction project management consists of number
of processes and these can be grouped under the
following management functions:
a) Scope management,
b) Procurement management,
c) Time management,
d) Cost management,
e) Quality management,
f) Risk management,
g) Communication management,
h) Human resources management,
j) Health and safety management,
k) Sustainability management,
m) Integration management, and
n) Other management processes.
The project management functions briefly described
below may be employed for effective management of
construction project during its different stages as
applicable. Some of the processes may, however,
overlap more than one function.
4.3.1 Scope Management
It should be ensured that project concept, details and
functions which are established and recorded during
the finalization stage, remain same except minor
changes and/or authorized variations. Scope
management includes the processes of scope planning,
scope definition, scope verification, scope monitoring,
and change control.
Scope planning, scope definition and scope verification
are associated with the preconstruction phase of the
project. Scope monitoring and change control are
critical to the construction/installation stage in order
to control time and cost over-runs. The work break
down structure of the project shall be the basic tool for
defining the scope baseline. Scope control should aim
to identity factors influencing scope change, determine
the impact of scope changes and establish the system
for scope change approval and revision of scope
baseline. Accordingly, a detailed scope management
plan should be drawn to lay down all the necessary
practices including technical and organizational
interfaces.
For detailed guidelines, reference shall be made to good
practice [7(4)].
4.3.2 Procurement Management
Procurement management includes processes for
purchase of materials, equipment, products, soliciting
services of consultants and engaging agencies for
execution of works under a contract. Project
procurement processes, which depend on type of
project delivery model include identification of
procurement needs, preparation for procurement,
soliciting proposals, selection of suppliers/consultants/
works contractors, administering of corfffact, contract
management and closure of contract. Project manager
is charged with the responsibility to help structure and
develop contract to suit the specific needs of the project.
As contract, which is an output of project procurement
management processes, is a legal document, the
procurement processes should follow detailed
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procedures with adequate review and stakeholder
appraisal opportunities.
One of the fundamental issues in construction projects,
managed through project managers, is to determine
what needs may be met by procuring products, services
and works from external agencies and what should be
accomplished by the project team. This decision is best
arrived at the earlier stages of the project (so that the
opportunities of procurement initiation at earlier stages
is not lost) and reviewed at each of the subsequent life
cycle stages of the project. Such decisions should draw
inputs from the time, cost, quality and scope
management processes. Various procurement routes
should be analysed on their suitability to both time and
cost criteria of project. As a strategy for procurement,
a project procurement management plan should be
developed to document: contract types to be used;
procurement documents; coordination of procurement
with schedules; constraints and assumptions; risk
mitigation activities (performance bonds, insurances,
etc); and pre-qualification of suppliers. In addition,
specifications, quality standards, performance data at
work locations, etc, which are part of project scope
statement, should be described. Inventory management
plays an important role in the procurement management
process.
Provision of establishment of suitable dispute redressal
system should be inbuilt to take care of any disputes
that may arise.
For detailed guidelines, reference shall be made to good
practice [7(5)].
4.3.3 Time Management
Time management aims to complete the project within
the stipulated time period. Time management essentially
involves the following processes:
a) Defining project scope in the form of work
breakdown structure to generate activity
identification and listing,
b) Activity duration estimating,
c) Activity sequencing with interactivity
dependencies,
d) Project schedule development, and
e) Project schedule control.
Work breakdown structure should be used as a tool to
prepare the project schedule by defining the project
scope and identifying and listing of the activities in the
work packages. For the quantum of work involved in
the activities, the activity durations are estimated based
on the standard productivity norms for different trades
of work. Past-documented experience and expertise
should also be used for determination of the activity
durations with the construction technology adopted and
manpower and equipment resources used. Based on the
construction methodology proposed with the
consideration of project specific constraints, the
sequencing and interdependencies of the activities are
determined and the graphical representation of activities
in the form of network should be prepared. The network
thus prepared should be analysed to develop the project
schedule with information on early and late start and
finishing of activities with their available floats and
the critical path/critical activities on the network.
Incorporating the calendar dates, the baseline schedule
may be finalized with the incorporation of milestones
for subsequent schedule monitoring and control
processes.
During the construction stage, schedule monitoring
involves methods of tracking and comparing the actual
schedule with the baseline schedule and schedule
control activities should ensure to remove deficiencies
and slippages corrected to acceptable levels.
Project scheduling and monitoring is a dynamic process
and periodic schedule updating should be done for
effective monitoring and control process. In the process,
the status of each activity should be examined. For
completed activities, actual durations utilized, are
incorporated; and for activities in progress, balance to
complete revised durations and estimated finish dates
are determined and incorporated. If the actual schedule
lags behind the baseline schedule, various options
should be considered to control and bring back the
schedule to acceptable levels. The possible control
actions, which may be considered, are: possible
reduction in activity duration of future activities with
alternate technology options, increasing the resources,
alteration in the construction logic and activity
sequencing, etc.
For detailed guidelines, reference shall be made to good
practice [7(6)].
4.3.4 Cost Management
The objective of the project cost management is to
ensure that the project is completed within the
authorized budget. The major processes involved in
the cost management are: resource planning, cost
estimation, cost budgeting/cost planning and cost
monitoring and control. The resource planning involves
determination of various types of resources, such as
appropriate technology, workforce, materials,
equipment and infrastructure facilities, their quantum
and their requirements during different stages of the
project. Preliminary cost estimate with defined scope
of work is required for obtaining the project sanction.
Detailed item wise cost estimates with bill of quantities
and specifications should be made for tendering and
subsequent project execution. The type of contract
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
13
adopted such as item rate, percentage rate, lump sum
and cost plus, influences the cost management strategy.
Most of the cost optimization techniques through value
engineering studies are achieved during the
preconstruction stage of the project. Value engineering
is a useful technique for application in cost
management. It is a systematic multi-disciplinary effort
directed towards analyzing the functions of project or
item for the purpose of achieving the best value at the
lowest overall life cycle project cost. It is an established
technique for determining value based decisions rather
than cost reduction based on change in specifications.
Suitability of construction techniques, selection of
equipment for specific purposes, considering
alternative materials and other design changes are some
of the areas of application of value engineering.
During construction stage, the efforts are more on
control mode for adherence to the budgeted cost. For
the purpose of cost control during execution, the time
based cost baseline of the project which forms the basis
for the measurement and monitoring of cost
performance, should be generated. The cost baseline
is generated by allocating the overall cost estimate to
individual project activities based on the project
schedule. Using the cost baseline, the cost control,
which comprises the following, should be exercised:
a) Periodical cost reporting,
b) Comparison of the actual cost against the
planned cost,
c) Obtaining early warning for corrective actions,
d) Control and monitoring cost changes,
e) Forecasting of final cost at completion based
on cost trend and cost changes, and
f) Modification of the cost baseline for
authorized cost changes and preparation of
revised estimates.
For detailed guidelines, reference shall be made to good
practice [7(7)].
4.3.5 Quality Management
Quality management in construction aims to achieve
required functional and physical characteristics of a
constructed facility through management actions
including planning, direction and control. Quality is
the key determinant of requirements which is expressed
through drawings and specifications. Main function of
quality management is to achieve quality objective of
satisfying requirements through performance evaluation
of construction processes and ensure that they are
directed towards overall quality. Quality management
during construction stage assumes that the design and
specifications comprehensively incorporate
requirements of users and other stakeholders. Prior to
setting out for the construction, the client should
completely understand the implications of changes to
the design and specifications during the construction
stage, which may affect quality.
Although quality is an all-encompassing concept which
also has bearing on time and cost aspects, the specific
scope of quality management may be limited to its key
functions of quality planning, quality assurance and
quality control. Quality planning refers to the
identification of relevant quality standards and
determining how to satisfy them. Quality assurance
activities include consistent evaluation of project
performance to provide confidence that the project
satisfies the relevant quality standards. Quality control
monitors project results related to the compliance to
quality standards and identifying means to eliminate
non-conformity.
On-site operations constitute most of the construction
processes. Scope of quality management for on-site
operations may be categorized broadly in three distinct
stages. In the receiving stage, materials and supplies
are inspected and tested for conformance to the
specified standards. During ‘in-process stage’, materials
and supplies are processed to form project product
components wherein process control ensures
conformance to the specified standards. In the ‘final
stage’, inspections and tests monitor the functional and
physical performance of the product/service to ensure
that they satisfy the requirements.
Planning being an integral part of the quality
management, may also consider efficient site layout
and its management for on-site operations. In addition
to time and cost implications of the site management,
the quality performance improves by efficient
organization of activities by way of providing adequate
and appropriate conditions for the work processes. Site
management needs to consider construction technology
constraints with reference to aspects related to space
availability such as permanent services, access to site,
temporary services, location of material stores, stacking
and storage areas and plants, fencing and other
temporary structures.
The various organizations connected with the project
should have their own quality management systems.
For detailed guidelines, reference shall be made to good
practice [7(8)].
4.3.6 Risk Management
Project risks have an impact on the project objectives
and need a planned response. Project risk management
processes ensure proper planning, identification,
analysis, monitoring and control to the best interest of
the project.
14
NATIONAL BUILDING CODE OF INDIA 2016
Risk management planning processes develop an
approach to risk management activities which include
planning, execution and monitoring. A risk management
plan should define lead and support role responsibilities
of project team in relation to management, budgeting,
risk responsive scheduling, classification of risk
activities based on risk break-down structure and
explanation of probability and impact for risk context.
Risk response planning detennines actions required for
reducing unpact of risks. Risk responses are established
and assigned to appropriate project participants.
Suitable risk mitigation measures should be evolved
for identified risks.
For detailed guidelines, reference shall be made to good
practice [7(9)].
4.3.7 Communication Management
For communication management, Management
Information System (MIS) is used as an important tool
for systemized approach to furnish information. It
comprises a system that collects, stores, sorts and
analyses data to generate and communicate information.
It may be a combination of manual and computerized
systems.
At the construction stage of a project, there are many
agencies involved like client, architect, engineer,
project manager, various consultants, material
suppliers, construction agencies and sub-contractors.
Each agency is divided into top level management
taking policy decisions, middle level management
monitoring the project and lower level management
involved in day to day operations of the project.
Each level of management requires information of
varying details, at different periodicities and in different
formats. Project progress information flows from lower
level to the top level management and policy decisions
flow from top level to the lower level management.
MIS integrates the work and information flow within
each agency and flow of information between different
agencies.
In construction stage of the projects, the information
may be in the form of data reflecting status of project
in terms of actual execution time for each activity, cost
incurred, resources used, quality control, material
management, bills, organization management and other
administrative aspects like disputes that may come up.
This data should be analysed to understand the overall
progress achieved and to update schedules of the
project.
Basic objectives of MIS of a construction project may
be summarized as:
a) Providing benchmark against which to
measure or compare progress and costs, like
time network schedules, cost estimates,
material and labour schedules, specifications,
working drawings.
b) Providing an organized and efficient means
of measuring, collecting, verifying and
reflecting the progress and status of operations
on the project with respect to progress, cost,
resources and quality.
c) Providing an organized, accurate and efficient
means of converting the data from operations
into information.
d) Reporting the correct and necessary
information in the required format and at the
required level of detail to managers at all
levels and to the supervisors.
e) Identifying and isolating the most important
and critical information at various stages to
be communicated to the managers and
supervisors for taking decisions.
f) Communicating the information to the
managers and supervisors in time so that
decisions may be taken at the right time.
Total MIS configuration of the construction project may
be divided into the following modules:
1) Planning and scheduling module,
2) Cost control and accounting module,
3) Trend and forecast module,
4) Project administrative and financial module,
and
5) Historical and documentation module.
All modules should be interlinked in flow of
information and generation of reports.
For large public projects, suitable mechanism may be
established for communication of relevant information
to public at large.
For detailed guidelines, reference shall be made to good
practice [7(10)].
4.3.8 Human Resource Management
All construction projects involve large number of
skilled/unskilled persons. Human resources in a project
should be adequately qualified, trained and competent.
Quality of construction work depends on the quality of
labour resource. For skilled and un-skilled labour, the
requirement for technical knowledge, skill and general
awareness are varied for different construction
processes. Labourers are required to understand their
respective responsibilities especially towards the work.
Therefore, construction management practices should
emphasize on development of competence of this
critical human resource through training programmes.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
15
The critical activities should be identified from the point
of view of technological innovations, workmanship and
environmental conditions which determine labour
behaviour and performance. In each construction
project, there are certain work related peculiarities
which call for job specific orientation. There should
be a clearly defined competence requirement for the
workers. Progressively, a formal training or a certified
course undertaken should be a preferred selection
criterion for the workers. All efforts should also be made
to impart on site skilling/training of construction
workers for specific tasks. A periodic review of the
performance may be made to establish the nature of
training required and methods for imparting training.
There is a need to address the motivational aspects, for
better performance.
For detailed guidelines, reference shall be made to good
practice [7(11)].
4.3.9 Health and Safety Management
4.3.9.1 Health management issues include looking into
the risk factors to health of construction personnel and
providing hygienic conditions at construction sites and
methods of their management. It includes managing,
a) occupational/physical health hazards.
b) short term as well as long-term ill effects of
the activities and the working environment of
the construction sites.
c) provision of personal protective equipment
required for specific health hazards.
d) laying down of construction hygiene control
methods.
4.3.9.2 Safety management issues include managing
work processes, equipment and material handling at
site for striving to achieve zero accident status at site.
For prevention and management of accidents, a proper
organizational and administrative mechanism is
required. Following steps should be taken for achieving
the same:
a) Laying down of safety regulations or
mandatory prescriptions concerning different
work processes.
b) Standardization of work processes and
management actions.
c) Regular and stipulated inspection of works and
machinery/equipment for enforcement of
mandatory regulations.
d) Providing education and training to workers
on safety issues.
e) Publicity and appeal to develop safety
consciousness.
f) Insurance of built facilities, construction
personnel and third party.
g) Regular safety audit of construction sites and
post audit actions.
h) Effective post-accident action including
accident analysis and reporting.
j) Effective post-accident management including
corrective measures to avoid repetition of such
accidents.
Safety Officer shall be appointed in accordance with
the concerned provisions of the Building and Other
Construction Workers (Regulation of Employment and
Conditions of Service) Act, 1996. Safety officer who is
posted at a medium to major construction site shall:
1) Look after the safety of the personnel, safe
handling of materials and machinery, safe
work practices and standard operating
procedures.
2) Be responsible for compliance of all statutory
obligations of the employer in regard to safety
of personnel and structures.
3) Guide and assist the site managers/engineers
to make their sites safe and accident free.
4) Train personnel in construction safety, conduct
safety surveys and design suitable documents
for recording and promoting safety on sites
and in the construction industry.
5) Arrange for safety briefing for all the persons
entering the construction area.
For detailed guidelines, reference shall be made to good
practice [7(12)].
4.3.10 Sustainability Management
4.3.10.1 Sustainability management issues include the
following:
a) Minimizing adverse environmental impact of
activities, products and services.
b) Limiting any adverse impact within the laws/
prescribed norms and their monitoring.
c) Safety of environment while working with
hazardous materials and maintaining material
safety data sheets.
d) Management of disposal of waste from the
construction sites.
e) Considering positive environmental
contribution particularly after completion of
construction.
f) Mechanism to review concerns of interested
parties.
For detailed guidelines, reference shall be made to good
practice [7(13)].
4.3.11 Integration Management
Integration management aims to provide processes
16
NATIONAL BUILDING CODE OF INDIA 2016
necessary for coordination amongst various
organizations and their teams involved. It ensures that
various organizational teams perform in an integrated
manner, with their actions coordinated to the mutual
interests towards the project. Integrated management
processes provide opportunities for resolving conflicts
and competing interests through appropriate tradeoffs.
Integration is necessary where processes interact,
especially when process responsibilities belong to
different organizational groups. Such process
interactions need organizational interfaces to be defined
and resolved at an overall level.
Integration management may also be required for
specific situations when impact of one management
function is a cause for concern for other management
functions. For example, if there is a time delay in
performing a particular construction process, it may
often have impact on the cost aspects of not only that
process but other processes involving other
organizational groups; the rescheduling may affect
coordination amongst performing groups in the down¬
stream processes and activities.
For detailed guidelines, reference shall be made to good
practice [7(14)].
SECTION 2 CONSTRUCTION PLANNING
AND SITE MANAGEMENT
5 PLANNING ASPECTS
Construction planning aspects aim to identify and
develop various stages of project execution on site
which should be consistent with the management
considerations. Planning aspects evolve out of the
objectives of project and requirements of the final
completed constructed facility. These objectives could
relate to the time constraints, cost considerations,
quality standards, safety standards, environmental
considerations and health considerations. Construction
practices would, then have to satisfy these objectives
during construction phase of the project.
Having established objectives of the construction phase,
planning determines processes, resources (including
materials, equipment, human and environmental) and
monitoring system to ensure that the practices are
appropriately aligned. Adequate knowledge about
preconstruction phase evolution of project, especially
related to customer’s requirements, is an essential
prerequisite for construction planning.
5.1 Preconstruction Phase
5.1.1 Besides the design aspects, preconstruction phase
should also address all the issues related to the
implementation of the design at the site through suitable
construction strategy. During the design stage, the site
conditions should be fully understood with anticipated
difficulties and avoid the risk of subsequent delays and
changes after the construction has started.
5.1.2 The selection of construction methods, building
systems and materials, components, manpower and
equipment and techniques are best done in the
preconstruction phase. Such selection is influenced by
the local conditions like terrain, climate, vulnerability
for disasters, etc.
5.1.3 Construction in busy localities of cities needs
special considerations and meticulous planning due to
restricted space, adjoining structures, underground
utilities, traffic restrictions, noise and environmental
pollution and other specific site constraints.
5.1.4 The constructability aspects of the proposed
construction methods needs to be carefully evaluated
at the planning stage to ensure ease of construction
besides optimizing the construction schedule and
achieving quality, reliability and maintainability of the
constructed facilities.
5.1.5 Construction practices in hilly regions needs to
take into considerations the problem of landslides, slope
stability, drainage, etc, besides ensuring no adverse
impact on the fragile environmental conditions.
5.1.6 Durability of constructions in corrosive
atmospheric conditions like coastal regions and
aggressive ground situations with high chlorides and
sulphates should also be taken care of with appropriate
construction practices.
5.1.7 Construction practices in disaster prone areas need
specific planning. The type of construction, use of
materials, construction techniques require special
considerations in such areas.
5.1.8 Adverse weather conditions have strong bearing
on construction phase. Situations wherein constructions
are to be carried out in adverse weather conditions,
such as heavy and continuous rain fall, extreme hot or
cold weather, dust storms, etc, the practices have to
address the relevant aspects. Accordingly, suiting the
site conditions, the design and field operations should
be adapted or redefined based on considerations, such
as the following:
a) Site layout which enables accessibility in
adverse weather.
b) Adequate protected storage for weather
sensitive materials/equipment.
c) Protection to personnel from extreme hot/cold
conditions.
d) Scheduling to allow maximization of outdoor
activities during fair weather conditions.
e) Special design and construction provisions for
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
17
activities in extreme temperature conditions
like hot or cold weather concreting, stability
of false work in extreme wind conditions
(gusts).
f) Adequate lighting for shorter days in winter/
night work.
g) Design for early enclosure.
5.2 Resource Planning
Resource planning aims to identify requirement,
availability and regulatory/control processes related to
resources. Resource planning is a generic expression
but the actual process of planning is specific to the
resources considered {see also 4.2.3.2.3).
In construction phases, the resources could be
categorized as materials, manufactured products,
equipment for construction, installation and fabrication,
human resources as a part of overall organization,
information resources such as reference standards and
other practice documents, environmental conditions for
work on site, infrastructure facilities and cash flow.
Therefore, the resource planning encompasses
identification, estimation, scheduling and allocation of
resources. Resource planning needs to establish a
control system for controlling consumption monitoring,
corrective action and resource reappropriation in the
event of favourable deviation. Organizational
capability, commitment to the project requirements and
other constraints such as time and cost, need to be
considered as inputs while planning resources.
Techniques of management and planning such as
Programme Evaluation and Review Technique (PERT)
and Critical Path Method (CPM) may be used.
Non-availability of basic building materials (brick,
stone, aggregate, etc) within reasonable lead would
influence the construction practice by alternative
materials. The construction practices also get decided
by the local skills of the manpower for construction
activities. The equipment selection would also be.
governed by the site constraints. Source of funding of
the project and its timeliness with reference to
requirement of cash flow should also merit
consideration. Therefore, as, the resource planning is
critical to the project viability itself, the inputs to the
resource planning need to be validated appropriately
and established for such management. Resource
planning should establish a proper system of data
collection so as to facilitate effective resources control
mechanism. Resource planning responsibility has to be
specifically defined in the overall organizational setup.
5.3 Construction Phase
5.3.1 Organizational Structure
The site management should be carried out through
suitable site organization structure with roles and
responsibilities assigned to the construction personnel
for various construction related functions.
5.3.2 Site Management
5.3.2. 1 Site layout
The layout of the construction site should be carefully
planned keeping in view the various requirements of
construction activities and the specific constraints in
terms of its size, shape, topography, traffic, and other
restrictions, in public interest. A well planned site layout
would enable safe smooth and efficient construction
operations. The site layout should take into
considerations the following factors:
a) Easy access and exit, with proper parking of
vehicle and equipment during construction
b) Properly located material stores for easy
handling and storage.
c) Adequate stack areas for bulk construction
materials.
d) Optimum location of plants and equipment
(batching plants, etc).
e) Layout of temporary services (water, power,
power suppression unit, hoists, cranes,
elevators, etc).
f) Adequate yard lighting and lighting for night
shifts.
g) Temporary buildings; site office and shelter
for workers {see 14) with use of non¬
combustible materials as far as possible
including emergency medical aids.
h) Roads for vehicular movement with effective
drainage plan.
j) Construction safety with emergency access
and evacuations and security measures.
k) Fabrication yards for reinforcement assembly,
concrete precasting and shuttering materials.
m) Fencing, barricades and signages.
5.3.2. 2 Access for firefighting equipment vehicles
Access for firefighting equipment shall be provided to
the construction site at the start of construction and
maintained until all construction work is completed.
Free access from the street to fire hydrants/static water
tanks, where available, shall be provided and
maintained at all times. No materials for construction
shall be placed within 3 m of hydrants/static water tanks.
During building operations, free access to permanent,
temporary or portable first-aid firefighting equipment
shall be maintained at all times.
5.3.2.3 Access to the upper floors during construction
In all buildings over two storeys high, at least one
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NATIONAL BUILDING CODE OF INDIA 2016
stairway shall be provided in usable condition at all
times. This stairway shall be extended upward as each
floor is completed. There shall be a handrail on the
staircase.
5.3.2.4 Electrical installations
Electrical installations, both permanent and temporary,
for construction and demolition sites, including
electrical installations for transportable construction
buildings (site sheds) shall be in accordance with 12 of
Part 8 ‘Building Services, Section 2 Electrical and
Allied Installations’ of the Code.
5.3.3 Construction Strategy and Construction
Sequence
Construction strategy and construction methods are to
be evolved at the planning and design stage specific to
the conditions and constraints of the project site and
implemented by the site management personnel to
ensure ease of construction and smooth flow of
construction activities. Sites of high water table
conditions with aggressive chemical contents of subsoil
needs special design considerations. Buildings with
basement in sites of high water table should be planned
with dewatering scheme with appropriate construction
sequence. Duration of dewatering should continue till
sufficient dead loads are achieved to stabilize the
buoyancy loads with adequate factor of safety. The
construction sequence should be planned taking into
consideration the following aspects:
a) Availability of resources (men, material and
equipment);
b) Construction methods employed including
prefabrication;
c) Planned construction time;
d) Design requirements and load transfer
mechanism;
e) Stability of ground like in hilly terrain;
f) Ensuring slope stability with retaining
structure before the main construction;
g) Installation and movement of heavy
equipment like cranes and piling equipment;
h) Effect of weather; and
j) Minimum time to be spent on working below
ground level.
SECTION 3 CONSTRUCTION PRACTICES
6 CONSTRUCTION CONTROL AND
PRACTICES
6.1 Professional Services and Responsibilities
The responsibility of professionals with regard to
planning, designing and supervision of building
construction work, etc and that of the owner shall be in
accordance with Part 2 ‘Administration’ of the Code.
All applications for permits and issuance of certificates,
etc shall be as given in Part 2 ‘Administration’ of the
Code. Employment of trained workers shall be
encouraged for building construction activity.
6.2 Site Preparation
6.2.1 While preparing the site for construction, bush
and other wood, debris, etc, shall be removed and
promptly disposed of so as to minimise the attendant
hazards.
6.2.2 Temporary buildings for construction offices and
storage shall be so located as to cause the minimum
fire hazards and shall be constructed from non¬
combustible materials as far as possible.
6.3 Habitat for Construction Workers at Site
The habitat and other welfare measures for construction
workers shall meet the requirements specified in 14.
6.4 Construction of All Elements
6.4.1 Construction of all elements of a building shall
be in accordance with good practice [7(15)]. It shall
also be ensured that the elements of structure satisfy
the appropriate fire resistance requirements as specified
in Part 4 ‘Fire and Life Safety’ of the Code, and quality
of building materials/components used shall be in
accordance with Part 5 ‘Building Materials’ of the
Code.
6.4.2 Construction of all accessibility features/elements
in a building and its built environment shall be as per
the requirements given in 13 of Part 3 ‘Development
Control Rules and General Building Requirements’ of
the Code.
6.4.3 All mechanical, electrical and plumbing (MEP)
and other services in a building shall be installed in
accordance with approved designs as per Part 8
‘Building Services’ of the Code and Part 9 ‘Plumbing
Services including Solid Waste Management’ of the
Code. Proper sequencing of installation of various
services shall be done for ensuring smooth construction
activities.
6.4.4 Necessary temporary works required to enable
permanent works, shall be executed in accordance
with 7.
6.5 Low Income Housing
For low income housing, appropriate planning and
selection of building materials and techniques of
construction have to be judiciously done and applied
in practice. Requirements of low income housing
specified in Part 3 ‘Development Control Rules and
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
19
General Building Requirements’ of the Code shall be
followed. However, all requirements regarding
structural safety, health safety and fire safety shall be
in accordance with this Part.
6.6 Use of New/ Alternative Construction Techniques
The provisions of this Part are not intended to prevent
use of any construction techniques including any
alternative materials, not specifically prescribed by the
Code, provided any such alternative has been approved.
The Authority may approve any such alternative, such
as, ferrocement construction; stretcher bond in filler
slab; glass fibre reinforced gypsum (GFRG) panel
system using composite of GFRG panel and reinforced
concrete; pre-engineered steel structures with
reinforced concrete expanded polystyrene core based
panel/other in-fill walls; light gauge steel framed
structures with suitable water resistant wall panels like
cement bonded particle board, provided it is found that
the proposed alternative is satisfactory and conforms
to the provisions of relevant parts regarding material,
design and construction and that material, method, or
work offered is, for the purpose intended, at least
equivalent to that prescribed in the Code in quality,
strength, compatibility, effectiveness, fire and water
resistance, durability and safety.
6.7 Urban Roads/City Roads Planning and
Construction
6.7.1 The urban roads, which are commonly known as
city roads/streets have been under constant
development. The emphasis has been primarily on
providing essentially required width of metalled surface
for the movement of vehicles (both motorized and non-
motorized). Footpaths of various widths and heights
are required to be provided.
The space between the buildings and the city roads
should be treated as valuable and important space
allowing for a comfortable and safe use by the
pedestrians, hawkers, cyclists including non-motorized
vehicle (NMV) drivers, and adequate space for
drainage, utilities, street lighting poles, transformers
and trees. Thus, the objective should be to create urban
streets/roads that are efficiently planned, safe for
vehicles as well as pedestrians, universally user friendly,
and sustainable.
The elements required in an efficiently planned street,
such as, kerb stones; kerb channels; kerb ramps; tactile
ground surface indicators; silt chambers with manhole
cover; drain cover slabs; drain manhole covers; service
pipes; manhole covers for electrical services; manhole
covers for telecom services; cycle tracks (NMV);
bollards across pedestrian paths; tree gratings; lighting
poles on main roads and service roads; table tops on
free left turns; pedestrian paths at intersections/
T-junctions; pedestrian paths on traffic islands;
pedestrian paths across central verge; pedestrian paths
near rotaries (un-signaled); pedestrian paths below
flyovers; signages; traffic signals; cable ducting by
discoms; central verge irrigation system; central verge,
footpath and traffic islands plantation; street furniture;
bus queue shelters; public art, public toilets, etc. should
be identified. These elements should be integrated at
the planning stage, indicating the methodology of
execution, taking care of the following while complying
with the relevant rules/regulations:
a) Road cross-section planning based on land-
use with emphasis on smooth vehicular
movements.
NOTE — This may be achieved by rationalizing lane widths
based on norms laid down by Indian Roads Congress.
b) Design of road intersections, fixing of
geometries of roads, providing provision of
entry and exits from the service roads.
c) Coordination between the traffic police,
transport authorities and the executing
agencies to be ensured for efficient location
of traffic signals, zebra crossings and the bus
queue shelters and the pickup stands for the
para-transport.
d) Standardization of kerb stones, kerb ramps and
kerb channels.
e) Appropriate selection of materials, like, paver
blocks, tiles, stone slabs or plain cement
concrete for footpaths, plazas, etc, so that they
add to aesthetics of buildings and roads.
f) Standardization of access manhole covers for
various utilities.
g) Providing footpath at one level by adjusting
the drain cover slab levels.
h) Integration of bus queue shelters with the
footpath.
j) Pedestrian friendly access across the roads to
the foot-over bridges, subways and public
toilets.
k) Access to gates of residential/commercial
properties integrated with the road through the
footpath in front.
m) Sharing of NMV with footpath necessary at
many locations.
n) Adequate provision of public conveniences
and dust bins.
p) Street lighting for proper illumination of roads
and service roads including modifications of
street lighting along with central verge and the
service roads blocked by existing trees.
q) Low height plantation on central verges,
avoiding plantation of trees.
20
NATIONAL BUILDING CODE OF INDIA 2016
r) Removal of crooked trees on footpaths for
proper and safe utilization of footpath.
s) Removal of trees obstructing the carriage ways
and their replantation, wherever feasible.
t) Freeing of trees embedded in the compound
wall/dwarf walls on footpaths to save both the
trees and the walls.
u) Providing planters in the central verge in the
deck portion of flyover to ensure proper glare
cutting during night hours and improving
aesthetics during the day.
w) Proper location of signage boards so as to be
safe from moving traffic near the footpath
edges and give clear visibility.
y) Selection, procurement and installation of
street furniture.
z) Selection, procurement and installation in
respect of accessibility features as per the
requirements given in 13 of Part 3
‘Development Control Rules and General
Building Requirements’ of the Code.
NOTE — The relevant standards/publications of Indian Roads
Congress may be referred to.
6.7.2 The road work zones are areas of conflict between
normal operating traffic, construction workers, road
building machineries and construction traffic. If it is a
construction of new road, normal operating traffic will
not be there but the care has to be taken to avoid and or
remove conflicts between workers and construction
machineries and construction traffic. Problem becomes
more serious if it is an urban road with significant
proportion of vulnerable road users. The road work
zones and the traffic around them should be so planned
and managed so as to ensure traffic safety, facilitate
smooth and efficient flow of traffic and also provide
safe working environment for the workers.
NOTE — For guidance on management of pedestrians/cyclists/
vehicles near road construction sites, reference may be made
to IRC SP 55 : 2014 ‘Guidelines on traffic management in work
zones’.
6.8 Measures against pollution and hazard due to dust,
smoke and debris, such as screens and barricading shall
be installed at the site during construction. Plastic/
tarpaulin sheet covers shall be used for trucks
transporting fine materials liable to cause environmental
pollution.
7 TEMPORARY WORKS
7.1 The construction of most types of permanent works
requires the use of some form of temporary works.
Temporary works are the parts of a construction project
that are needed to enable the permanent works to be
built. Usually the temporary works are removed after
use, for example, access, scaffolds, props, shoring,
excavation support, false work and formwork,
etc. Sometimes the temporary works are incorporated
into the permanent works, for example, haul road
foundations and crane or piling platforms which may
be used for hard standing or road foundations. The same
degree of care and attention should be given to the
design and construction of temporary works as to the
design and construction of the permanent works.
Considering that as temporary works may be in place
for only a short while, there is a tendency to assume
they are less important, which is incorrect. Lack of care
in design, selection, assembly, etc, leaves temporary
works liable to fail or collapse. While organizing the
temporary works, aspects as given below should be
followed:
a) The person organizing the temporary works
should be aware of the problems that can occur
at each stage of the process and how to prevent
these. They need to coordinate design,
selection of equipment, appointment of
contractors, supervision of work, checking
completion, authorization to load and
removal.
b) If so required, a temporary works co-ordinator
(TWC) may be employed in case of medium
and large projects, whose requisite
qualification and experience should be
specified. The role of TWC and supervisor
should be decided. The coordinator shall have
adequate field training for temporary works.
The contractor shall ensure that work is
allocated and carried out in a manner that does
not create unacceptable risk of harm to
workers or members of the public. On
projects with relatively simple temporary
works needs, a TWC may be avoided,
however, it shall be ensured that temporary
works are properly managed.
c) The cost of any temporary works is generally
included in the build-up of the tender.
d) Temporary works are often taken from site to
site and re-used and it is important to consider
the robustness of components in their design.
However, temporary works that are designed
only to be used during construction shall not
be removed until the satisfactory safety criteria
for their use has been met.
e) Proper planning and co-ordination should be
done in respect of sequence and timely
execution of temporary works, as also for
ensuring that they are correctly installed, used,
checked and maintained.
f) In each of the cases of temporary works, the
person organizing the temporary works should
assess the soil conditions to be sure that it is
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
21
suitable for the equipment involved, and check
that any assumptions made in the calculations
for the standard solution are valid for this
particular situation and the conditions on site.
On a simple job, the supplier’s data will allow
an experienced person to consider the
necessary issues without further calculation.
g) Propping using standard equipment such as
screw props (acrows) needs careful
consideration. To select the type, size, number
and decide spacing, information is needed
about the loads that will act on the props. This
will include the wall above and the additional
load from any other floor or roof beams, etc,
that enter the wall above or close to the
opening. Even with proprietary equipment,
the support system shall be worked out.
h) A local failure within the temporary
works should not initiate a global collapse of
the structure. Therefore, additional care should
be taken while removing temporary works.
The different types of temporary works can be
scaffolding, crane supports, falsework, formwork, and
trench support. Detailed knowledge about each type of
temporary work is necessary for safe construction. The
requirements as given in 7.2 to 7.6 shall be satisfied in
case of temporary works.
Proprietary equipment supplier should be identified and
approved. It should be ascertained, whether following
has been performed:
1) They have designed the foundations,
2) Any assumption made that have to be
confirmed/investigated,
3) Independent checking done and by whom,
4) Status of drawings, and
5) Procedures checked at site.
In management of temporary works, the owner/client
has to ensure,
i) checks on competence on designers;
ii) steps taken to ensure co-operation between the
permanent and temporary works designers;
iii) coordination at site meetings; and
iv) advise clients on the suitability of the initial
construction phase plan, that is, the
arrangements for controlling significant site
risks.
7.2 Scaffolding
Scaffolding includes providing a temporary safe
working platform for erection, maintenance,
construction, repair, access, and inspection. Scaffolding
and their erection shall be in accordance with the good
practice [7(16)].
7.3 Tower Cranes
Tower cranes are usually supplied on a hire basis, with
the client being responsible for the design and
construction of the base upon which the crane is erected.
Details of loading are provided by the crane supplier
and the base is most commonly designed as a temporary
structure, though sometimes a crane base is
incorporated into the permanent structure to save on
cost and time.
Loads are given in two forms, ‘in service’ loads, where
the crane is functioning and wind speeds are restricted
(that is, cranes will not operate at high wind speeds),
and ‘out of service’ loads, where the crane is not being
used but maximum wind speeds may occur.
The location for a crane should be carefully selected
to provide a maximum working radius, and when two
cranes are being used on the same site, mast heights
and jib lengths shall be considered.
Cranes should typically be structured around two rails
at their base between 4.5 m and 1 0 m apart with wheels
in each comer. Cranes should not normally be tied
down, so sufficient kentledge should be provided so as
to ensure that vertical loading from the crane passes
through the rails and into the foundation.
The foundation shall be so designed that the unfactored
loading from the crane and the unfactored pressure is
less than the allowable bearing pressure of the soil.
Various foundation types can be selected depending on
the ground conditions. Where possible a structural fill
can be compacted and used to support a crane with the
load spreading through layers of track support at 45°
in to the soil strata below. When loads from the crane
increase, reinforced concrete foundations may be
required. This can involve a series of reinforced
concrete beams used to support line loads as a result of
the crane loading.
When ground conditions are particularly poor,
pile foundations may be necessary. The design shall
ensure that reinforcement at the top of the pile top
should not cause problems for positioning the mast base
section of the crane.
Tower cranes shall embody all fundamental principles
of design in accordance with the good practice [7(1 7)]
so as to secure reliability and safety in operation. The
particular requirements for controls for tower cranes
and the arrangement of basic control used for
positioning loads shall be in accordance with the good
practice [7(18)].
7.4 Falsework
Falsework involves a temporary structure used to
22
NATIONAL BUILDING CODE OF INDIA 2016
support other permanent structures until they can
support themselves. Falsework shall be designed and
erected in accordance with the good practice [7(19)].
7.5 Formwork
Formwork is the term used for a temporary mould into
which concrete is poured and formed. Traditional
formwork is fabricated using timber, but it can also be
constructed from steel, glass fiber reinforced plastics
and other materials.
Timber formwork is normally constructed on site
using timber and plywood. It is easy to produce,
although it can be time consuming for larger structures.
Re-usable plastic formwork is generally used for quick
pours of concrete. The formwork is assembled either
from interlocking panels or from a modular system and
is used for relatively simple concrete structures. It is
not as versatile as timber formwork due to the
prefabrication requirements and is best suited for low-
cost, repetitive structures such as mass housing
schemes.
Stay-in-place structural formwork is generally
assembled on site using prefabricated fibre-reinforced
plastic. It is used for concrete columns and piers and
stays in place, acting as permanent axial and shear
reinforcement for the structural member. It also
provides resistance to environmental damage to both
the concrete and reinforcing bars. Proprietary systems
are used to support vertical formwork while concrete
cures, consisting of series of tubes and ties.
When selecting formwork the type of concrete and
temperature of the pour are important considerations
as they both effect the pressure exerted on the
formwork. Striking of formwork shall be governed by
Part 6 ‘Structural Design, Section 5 Concrete:
Subsection 5 A Plain and Reinforced Concrete’ of the
Code.
High quality workmanship and inspection are
necessary to ensure a high standard of work including
finish.
7.6 Trench Support
A trench is defined as an excavation when its length
greatly exceeds its depth. Shallow trenches are usually
considered to be less than 6 m deep and deep trenches
have depth greater than 6 m. Depending on the
dimensions of a trench, excavation can either be carried
out by hand or by using a mechanical digger. Trenches
are commonly required to allow services, pipelines
or foundations to be laid.
Water ingress into the trench is often a major issue and
ground water table locations and soil strata should be
investigated before any extensive excavation takes
place. Over short periods of time, for relatively shallow
depths most soil types will stand almost vertically
without any problems. However, trenches other than
those which are relatively shallow may require a trench
support scheme. Traditionally, trenching involved
using timber to support horizontal and vertical soil
loads and this technique is still used today. Timber
trenching is generally used for low risk, narrow
trenches, shafts or headings. The timber solutions
require good workmanship and are reasonably labour-
intensive; however, they are versatile and the
equipment required is easy to handle and transport.
Trench boxes are suitable for low-risk situations in
stable, dry ground and can be placed in pre-excavated
trenches or installed using the ‘dig and push’ technique.
The system requires at least two struts at each panel
for stability which should be considered when access
is required for construction work or piping.
Trench sheets are the most adaptable of the systems
available, and are most commonly used to retain poorer
soil. They can support deeper trenches with larger
surcharges and provide a continuous support. They
require multiple levels of strut support and the
slenderness of the sheets can often limit the depth of
the trench as they are installed by light machinery and
could buckle under large vertical loads.
While making deep excavation near an existing
structure, it is necessary that the lateral force caused
by the existing structure should be taken care of.
Trench supports shall be provided in accordance with
the good practice [7(20)].
8 STORAGE, STACKING AND HANDLING
PRACTICES
8.1 General
8.1.1 Planning and Storage Layout
8.1. 1.1 For any site, there should be proper planning
of the layout for stacking and storage of different
materials, components and equipment with proper
access and proper manoeuvrability of the vehicles
carrying the material. While planning the layout, the
requirements of various materials, components and
equipment at different stages of construction shall be
considered.
8. 1.1. 2 Materials shall be segregated as to kind, size
and length and placed in neat, orderly piles that are
safe against falling. If piles are high they shall be
stepped back at suitable intervals in height. Piles of
materials shall be arranged so as to allow a passageway
of not less than 1 m width in between the piles or stacks
for inspection or removal. All passageways shall be
kept clear of dry vegetation.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
23
8. 1.1.3 Materials shall be stored, stacked and handled
in such a manner as to prevent deterioration or intrusion
of foreign matter and to ensure the preservation of their
quality and fitness for the work.
8. 1.1.4 Materials shall be stacked on well drained, firm
and unyielding surface. Materials shall not be stacked
so as to impose any undue stresses on walls or other
structures.
8. 1.1.5 Materials shall be stacked in such a manner as
not to constitute a hazard to passerby. At such places
the stacks shall have suitable warning signs in day time
and red lights on and around them at night.
8.1. 1.6 Stairways, passageways and gangways shall not
become obstructed by storage of building materials,
tools or accumulated rubbish.
8.1.2 Protection Against Atmospheric Agencies
Materials stored at site, depending upon the individual
characteristics, shall be protected from atmospheric
actions, such as rain, sun, winds and moisture, to avoid
deterioration.
8.1.3 Protection Against Fire and Other Hazards
8.1.3.1 Materials, like timber, bamboo, coal, paints,
etc, shall be stored in such a way that there may not be
any possibility of fire hazards. Inflammable materials
like kerosene and petrol, shall be stored in accordance
with the relevant rules and regulations so as to ensure
the desired safety during storage. Stacks shall not be
piled so high as to make them unstable under fire
fighting conditions and in general they shall not be more
than 4.5 m in height. The provisions given in good
practice [7(21)] shall be followed. Explosives like
detonators shall be stored in accordance with the
existing regulations of The Explosives Act, 1884.
8.1.3.2 Materials which are likely to be affected by
subsidence of soil like precast beams, slabs and timber
of sizes shall be stored by adopting suitable measures
to ensure unyielding supports.
8.1.3.3 Materials liable to be affected by floods, tides,
etc, shall be suitably stored to prevent their being
washed away or damaged due to floods, tides, etc.
8.1.4 Manual Handling
When heavy materials have to be handled manually
each workman shall be instructed by his foreman or
supervisor for the proper method of handling such
materials. Each workman shall be provided with
suitable equipment for his personal safety as necessary.
All workers shall wear adequate clothing to protect
themselves from direct sun-rays and other irritants.
Supervisors shall also take care to assign enough men
to each such job depending on the weight and the
distance involved.
8.2 Storage, Stacking and Handling of Materials
8.2.1 The storage, stacking and handling of materials
generally used in construction shall be as given in 8.2.2
to 8.2.31, which have been summarized in the form of
a check list in Annex A. Exposure to asbestos fibres/
dust is known to be harmful to health of human beings.
Prescribed guidelines in accordance with good practice
[7(22)] shall be followed for handling and usage of
asbestos cement products.
8.2.2 Cement
a) Storage and stacking — Cement shall be stored at
the work site in a building or a shed which is dry, leak-
proof and as moisture-proof as possible. The building
or shed for storage should have minimum number of
windows and close fitting doors and these should be
kept closed as far as possible.
Cement received in bags shall be kept in such a way
that the bags are kept free from the possibility of any
dampness or moisture coming in contact with them.
Cement bags shall be stacked off the floor on wooden
planks in such a way as to keep them about 150 mm to
200 mm clear above the floor. The floor may comprise
lean cement concrete or two layers of dry bricks laid
on a well consolidated earth. A space of 600 mm
minimum shall be left around between the exterior walls
and the stacks ( see Fig. 3). In the stacks the cement
bags shall be kept close together to reduce circulation
of air as much as possible. Owing to pressure on bottom
layer of bags sometimes ‘warehouse pack’ is developed
in these bags. This can be removed easily by rolling
the bags when cement is taken out for use. Lumped
bags, if any should be removed and disposed of.
The height of stack shall not be more than 10 bags to
prevent the possibility of lumping up under pressure.
The width of the stack shall be not more than four bags
length or 3 m. In stacks more than 8 bags high, the
cement bags shall be arranged alternately length-wise
and cross-wise so as to tie the stacks together and
minimise the danger of toppling over. Cement bags shall
be stacked in a manner to facilitate their removal and
use in the order in which they are received; a table
showing date of receipt of cement shall be put on each
stack to know the age of cement.
For extra safety during monsoon, or when it is expected
to store for an unusually long period, the stack shall be
completely enclosed by a water proofing membrane
such as polyethylene, which shall close on the top of
the stack. Care shall be taken to see that the
waterproofing membrane is not damaged any time
during the use.
Cement in gunny bags, paper bags and polyethylene
bags shall be stored separately.
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NATIONAL BUILDING CODE OF INDIA 2016
* 10 BAGS MAXIMUM A—1
SECTION XX
A = PLANKS
B = WOODEN BATTENS
C = 150 mm THICK LEAN CEMENT
CONCRETE OR DRY BRICKS
IN TWO LAYERS
D = 150 mm THICK/CONSOLIDATED EARTH
Fig. 3 Typical Arrangement in Cement Godown
In case cement is received in drums, these shall be
stored on plane level ground, as far as possible near
the concrete mixing place. After taking out the required
quantity of cement, the lid of the drum shall be securely
tied to prevent ingress of moisture.
In case cement is received in silos, the silos shall be
placed near the concrete batching plant. Proper access
shall be provided for the replacement of silos.
Different types of cements shall be stacked and stored
separately.
b) Handling — Hooks shall not be used for handling
cement bags unless specifically permitted by the
engineer-in-charge. Bags shall be removed uniformly
from the top of the piles to avoid tipping of the stack.
For information regarding bulk handling of cement
(see 8.2.4),
8.2.3 Lime
8.2.3. 1 Quicklime before slaking
a) Storage and stacking — Quicklime should be
slaked as soon as possible. If unavoidable it
may be stored in compact heaps having only
the minimum of exposed area. The heaps shall
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
25
be stored on a suitable platform and covered
to avoid direct contact with rain or being
blown away by wind. In case quick lime is
stored in a covered shed, a minimum space of
300 mm should be provided all-round the
heaps to avoid bulging of walls.
Unslaked lime shall be stored in a place
inaccessible to water and because of fire
hazards, shall be segregated from the
combustible materials.
b) Handling — See 8.2.4.
8.2.3.2 Hydrated lime
a) Storage and stacking — Hydrated lime is
generally supplied in containers, such as jute
bags lined with polyethylene or craft paper
bags. It should be stored in a building to
protect the lime from dampness and to
minimise warehouse deterioration.
The building should be with a concrete floor
and having least ventilation to eliminate
draughts through the walls and roof. In
general, the recommendations given in 8.2.2
for storing of cement shall be applicable for
hydrated lime. When air movement is reduced
to a practical minimum, hydrated lime can be
stored for up to three months without
appreciable change.
b) Handling — See 8.2.4.
8.2.3.3 Dry slaked lime
a) Storage and stacking — The lime shall be
stored in a dry and closed godown.
b) Handling — See 8.2.4.
8.2.4 Handling of Cement and Lime
Workers, handling bulk cement or lime shall wear
protective clothing, respirators, and goggles; shall be
instructed in the need of cleanliness to prevent
dermatitis, and shall be provided with hand cream,
petroleum jelly, or similar preparation for protection
of exposed skin. Workers handling cement, who are
continually exposed to it, shall, in addition to the above
be equipped with hand gloves and dust mask.
Bulk cement stored in silos or bins may fail to feed to
the ejection system. When necessary to enter a silo or
bin for any purpose, the ejection system employed shall
be shut down and locked out electrically as well as
mechanically. When necessary for a workman to enter
such storage area, he shall wear a life-line, with another
workman outside the silo or hopper attending the rope.
8.2.5 Masonry Units
a) Stones — Stones of different sizes, types and
classification shall be stored separately. Stones
shall be stacked on dry firm ground in a regular
heap not more than 1 m in height. Veneering
stones shall be stacked against vertical support
on a firm dry ground in tiers, upto a height of
1 .2 m. A distance of about 0.8 m shall be kept
between two adjacent stacks.
b) Bricks — Bricks shall be stacked in regular
tiers as and when they are unloaded to
minimise breakage and defacement. These
shall not be dumped at site. In the case of
bricks made from clays containing lime
Kankar, the bricks in stack should be
thoroughly soaked in water (docked) to
prevent lime bursting.
Bricks shall be stacked on dry firm ground.
For proper inspection of quality and ease in
counting, the stacks shall be 50 bricks long,
10 bricks high and not more than 4 bricks in
width, the bricks being placed on edge, two at
a time along the width of the stack. Clear
distance between adjacent stacks shall not be
less than 0.8 m. Bricks of each truck load shall
be put in one stack. Bricks of different types,
such as, clay bricks, clay fly ash bricks, fly
ash lime bricks, sand lime (calcium silicate)
bricks shall be stacked separately. Bricks of
different classifications from strength
consideration and size consideration (such as,
conventional and modular) shall be stacked
separately. Also bricks of different types, such
as, solid, hollow and perforated shall be
stacked separately.
c) Blocks - — Blocks are available as hollow and
solid concrete blocks, hollow and solid light
weight concrete blocks, autoclaved aerated
concrete blocks, concrete stone masonry
blocks and soil based blocks. Blocks shall be
unloaded one at a time and stacked in regular
tiers to minimise breakage and defacement.
These shall not be dumped at site. The height
of the stack shall not be more than 1 .2 m, the
length of the stack shall not be more than
3.0 m, as far as possible and the width shall
be of two or three blocks. Normally blocks
cured for 28 days only should be received at
site. In case blocks cured for less than 28 days
are received, these shall be stacked separately.
All blocks should be water cured for 10 to 14
days and air cured for another 1 5 days; thus
no blocks with less than 28 days curing shall
be used in building construction. Blocks shall
be placed close to the site of work so that least
effort is required for their transportation. The
date of manufacture of the blocks shall be
suitably marked on the stacks of blocks
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NATIONAL BUILDING CODE OF INDIA 2016
manufactured at factory or site.
d) Handling — Brick stacks shall be placed close
to the site of work so that least effort is
required to unload and transport the bricks
again by loading on pallets or in barrows.
Unloading of building bricks or handling in
any other way likely to damage the comers or
edges or other parts of bricks shall not be
permitted.
8.2.6 Floors, Wall and Roof Tiles
a) Storage and stacking — Floor, wall and clay
roof tiles of different types, such as, cement
concrete tiles (plain, coloured and terrazzo)
and ceramic tiles (glazed and unglazed) shall
be stacked on regular platform as far as
possible under cover in proper layers and in
tiers and they shall not be dumped in heaps.
In the stack, the tiles shall be so placed that
the mould surface of one faces that of another.
Height of the stack shall not be more than one
metre.
Tiles of different quality, size and thickness
shall be stacked separately to facilitate easy
removal for use in work. Tiles when supplied
by manufacturers packed in wooden crates
shall be stored in crates. The crates shall be
opened one at a time as and when required
for use.
b) Handling — Ceramic tiles and roof tiles are
generally supplied in cartons which shall be
handled with care to avoid breakage. It is
preferable to transport these at the site on
platform trolleys.
8.2.7 Aggregate
a) Storage and stacking — Aggregates shall be
stored at site on a hard dry and level patch of
ground. If such a surface is not available, a
platform of planks or old corrugated iron
sheets, or a floor of bricks, or a thin layer of
lean concrete shall be made so as to prevent
the mixing with clay, dust, vegetable and other
foreign matter.
Stacks of fine and coarse aggregate shall be
kept in separate stock piles sufficiently
removed from each other to prevent the
material at the edges of the piles from getting
intermixed. On a large job it is desirable to
construct dividing walls to give each type of
aggregates its own compartment. Fine
aggregates shall be stacked in a place where
loss due to the effect of wind is minimum.
b) Handling — When withdrawals are made
from stock piles, no overhang shall be
permitted.
Employees required to enter hoppers shall be
equipped with safety belts and life-lines,
attended by another person. Machine driven
hoppers, feeders, and loaders shall be locked
in the off position prior to entry, electrically
as well as mechanically.
8.2.8 Pulverized Fuel Ash/Fly Ash/Silica
a) Storage and stacking — Fly ash/Silica fume
shall be stored in such a manner as to permit
easy access for proper inspection and
identification of each consignment. Fly ash in
bulk quantities shall be stored in stack similar
to fine aggregates, avoiding any intrusion of
foreign matter. Fly ash in bags shall be stored
in stacks not more than 1 0 bags high. Silica
fume, in general, shall be stored similar to
cement/fly ash storage depending upon the
storage requirements in bags/bulk form.
b) Handling — See 8.2.4.
8.2.9 Cinder
Cinder shall be stored in bulk quantities in stacks similar
to coarse aggregates avoiding any extrusion of foreign
matter.
8.2.10 Timber
a) Storage and stacking — Timber shall be
stored in stacks upon well treated and even
surfaced beams, sleepers or brick pillars so
as to be above the ground level by at least
150 mm to ensure that the timber will not be
affected by accumulation of water under it.
Various members shall preferably be stored
separately in different lengths, and material
of equal lengths shall be piled together in
layers with wooden battens, called crossers,
separating one layer from another. The
crossers shall be of sound wood, straight and
uniform in thickness. In case, where separate
crossers are not available smaller sections of
the available structural timber may be
employed in their place. In any layer an air
space of about 25 mm shall be provided
between adjacent members. The longer pieces
shall be placed in the bottom layers and shorter
pieces in the top layers but one end of the stack
shall be in true vertical alignment. The crossers
in different layers shall be in vertical
alignment. The most suitable width and height
of a stack are recommended to be about 1.5 m
and 2.0 m. Distance between adjacent stacks
is recommended to be at least 450 mm. In case
the stacking with the help of battens is not
possible, the timber may be close piled in
heaps on raised foundations with the
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
27
precautions specified above.
The stacks shall be protected from hot dry
winds or direct sun and rain. Heavy weights,
such as metal rails or large sections of wood,
are recommended to be placed on the top of
the stack to prevent distortion or warping of
the timber in the stack. In case timber is to be
stored for about a year or more, to prevent end¬
cracking in the material, the ends of all members
shall be coated with coal tar, aluminium leaf
paints (hardened gloss oil), microcrystalline
wax or any other suitable material.
b) Care must be taken that handler or workers
are not injured by rails, straps, etc, attached
to the used timber. This applies particularly
to planks and formwork for shuttering.
8.2.11 Bamboo
8.2.11.1 The site shall be properly inspected and termite
colonies or mounds, if detected, shall be destroyed.
All refuse and useless cellulosic materials shall be
removed from the site. The ground may then be
disinfected by suitable insecticides. The area should
have good drainage.
8.2.11.2 Bamboo may preferably be stacked on high
skids or raised platform at least 300 mm above ground.
Storage under cover reduces the liability to fungal
attack. Good ventilation and frequent inspection are
important.
8.2.11.3 Bamboo dries by air-seasoning under cover
in the storage yards from 6 to 12 weeks’ time.
8.2.11.4 Prophylactic treatment of bamboo during
storage prevents losses due to fungi and insects even
under open storage. Following chemicals have been
found suitable at a coverage rate of 24 litre per tonne:
a) Sodium pentachlorophenate : 1 percent
solution.
b) Boric acid + borax (1:1) : 2 percent solution.
c) Sodium pentachlorophenate : 2.5 percent
solution + boric acid + borax (5:1:1).
A mixture of these compounds yields the best results.
NOTE — For better protection of structural bamboo (if stored
outside), repetition of the treatment after four to six months is
desirable.
8.2.12 Partially Prefabricated Wall and Roof
Components
a) Storage and stacking — The wall components
comprise blocks, sills, lintels, etc. The blocks
shall be stacked in accordance with 8.2.5 (c).
These shall be stacked on plane level ground
having a floor of bricks or a thin layer of lean
concrete.
The roof components such as precast RC
joists, prefabricated brick panels, RC planks,
channel units, cored units, waffle units,
L -panel, single tee and double tee sections,
ferrocement panels, etc shall be unloaded as
individual components. These shall be stacked
on plane level ground having a floor of bricks
or a thin layer of lean concrete. RC planks,
prefabricated brick panels and ferrocement
panels shall be stacked against a brick masonry
wall in slightly inclined position on both sides
of the wall. Channel units, cored units and
L-panels shall be stacked one over the other
up to five tiers. The waffle units shall be
stacked upside down as individual units. The
RC joists, single tee and double tee sections
shall be stacked as individual units one
adjacent to the other. The distance between
any two adjacent stacks shall not be less than
450 mm.
b) Handling — The components shall be handled
by holding the individual components at
specified points so that the stresses due to
handling are minimised.
8.2.13 Steel
a) Storage and stacking — For each
classification of steel, separate areas shall be
earmarked. It is desirable that ends of bars and
sections of each class be painted in distinct
separate colours. Steel reinforcement shall be
stored in a way as to prevent distortion and
corrosion. It is desirable to coat reinforcement
with cement wash before stacking to prevent
scaling and rusting.
Bars of different classification, sizes and
lengths shall be stored separately to facilitate
issues in such sizes and lengths as to minimise
wastage in cut from standard lengths.
In case of long storage or in coastal areas,
reinforcement bars shall be stacked above
ground level by at least 1 50 mm and a coat of
cement wash shall be given to prevent scaling
and rusting.
Structural steel of different sections, sizes and
lengths shall be stored separately. It shall be
stored above ground level by at least 150 mm
upon platforms, skids or any other suitable
supports to avoid distortion of sections. In case
of coastal areas or in case of long storage,
suitable protective coating of cement wash
shall be given to prevent scaling and rusting.
b) Handling — Tag lines shall be used to control
the load in handling reinforcements or
structural steel when a crane is employed.
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NATIONAL BUILDING CODE OF INDIA 2016
Heavy steel sections and bundles shall be
lifted and carried with the help of slings and
tackles and shall not be carried on the
shoulders of the workers.
8.2.14 Aluminium Sections
a) Storage and stacking — Aluminium sections
of different classification, sizes and lengths
shall be stored separately, on a level platform
under cover.
b) Handling — The aluminium sections shall not
be pulled or pushed from the stack nor shall
be slid over each other, to protect the
anodizing layer.
8.2.15 Doors, Windows and Ventilators
a) Storage and stacking — Metal and plastic
doors, windows and ventilators shall be
stacked upright (on their sills) on level ground
preferably on wooden battens and shall not
come in contact with dirt or ashes. If received
in crates they shall be stacked according to
manufacturer’s instructions and removed from
the crates as and when required for the work.
Metal and plastic frames of doors, windows
and ventilators shall be stacked upside down
with the kick plates at the top. These shall not
be allowed to stand for long in this manner
before being fixed so as to avoid the door
frames getting out of shape and hinges being
strained and shutters drooping.
During the period of storage of aluminium
doors, windows and ventilators, these shall be
protected from loose cement and mortar by
suitable covering, such as tarpaulin. The
tarpaulin shall be hung loosely on temporary
framing to permit circulation of air to prevent
moisture condensation.
All timber and other lignocellulosic material
based frames and shutters shall be stored in a
dry and clean covered space away from any
infestation and dampness. The storage shall
preferably be in well-ventilated dry rooms.
The storage shall preferably be in well-
ventilated dry rooms. The frames shall be
stacked one over the other in vertical stacks
with cross battens at regular distances to keep
the stack vertical and straight. These cross
battens should be of uniform thickness and
placed vertically one above the other. The door
shutters shall be stacked in the form of clean
vertical stacks one over the other and at least
80 mm above ground on pallets or suitable
beams or rafters. The top of the stack shall be
covered by a protecting cover and weighted
down by means of scantlings or other suitable
weights. The shutter stack shall rest on hard
and level surface.
If any timber or other lignocellulosic material
based frame or shutter becomes wet during
transit, it shall be kept separate from the
undamaged material. The wet material may
be dried by stacking in shade with battens in
between adjacent boards with free access of
dry air. Separate stacks shall be built up for
each size, each grade and each type of
material. When materials of different sizes,
grades and types are to be stacked in one stack
due to shortage of space, the bigger size shall
be stacked in the lower portion of the stacks.
Suitable pallets or separating battens shall be
kept in between the two types of material.
Precast concrete door and window frames
shall be stored in upright position adopting
suitable measures against risk of subsidence
of soil/support.
b) Handling — While unloading, shifting,
handling and stacking timber or other
lignocellulosic material based, metal and
plastic door and window frames and shutters,
care shall be taken that the pieces are not
dragged one over the other as it may cause
damage to their surface particularly in case of
the decorative shutters. The pieces should be
lifted and carried preferably flat avoiding
damage to comers or sides.
8.2.16 Roofing Materials
8.2.16.1 Roofing sheets shall be stored and stacked in
such a manner as not to damage them in any way.
8.2.16.2 Asbestos cement sheet
a) Storage and stacking — Asbestos cement
sheets shall be stacked horizontally to a height
of not more than 1 m on a firm and level
ground, with timber or other packing beneath
them. If stacked in exposed position, they shall
be protected from damage by wind. Asbestos
cement sheets of same variety and size shall
be stacked together. Damaged sheets shall not
be stacked with sound materials. All damaged
sheets shall be salvaged as early as possible.
b) Handling — Not more than two sheets shall
be first pushed forward along the valley line
say about one fourth of the sheet length and
preferably carried by two workers. Asbestos
cement sheets shall be lowered or raised gently
and not thrown.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
29
8.2.16.3 Corrugated galvanized iron sheets and
aluminium sheets
a) Storage and stacking — Corrugated
galvanized iron sheets and aluminium sheets
shall be stacked horizontally to a height of not
more than 0.5 m on a firm and level ground,
with timber or other packing beneath them.
To protect them from dust and rain water, these
shall be covered with tarpaulin or polyethylene
sheets.
b) Handling — In bulk handling of CGI sheets,
workers shall be provided with suitable hand
protection
8.2.16.4 Plastic sheets and glass reinforced plastic
(GRP) sheets
a) Storage and stacking — Plastic sheets and
glass reinforced plastic (GRP) sheets shall be
stacked under a shed to a height of not more
than 0.5 m on a firm and level ground with
timber or other packing beneath them.
b) Handling — Handling shall be done to avoid
any damage to the sheets.
8.2.17 Boards
8.2.17.1 Gypsum boards
a) Storage and stacking — Gypsum boards shall
be stored flat in a covered clean and dry place.
b) Handling — See 8.2.17.2 (b).
8.2.17.2 Plywood, fibre board, particle board, block
board, etc
a) Storage and stacking — Plywood, fibre board,
particle board, block board, etc, shall not be
stored in the open and exposed to direct sun
and rain. The boards shall be stacked on a flat
dunnage, on the top of which a wooden frame
shall be constructed with battens of
50 mm x 25 mm (Min) in such a way that it
supports all four edges and comers of the
boards with intermediate battens placed at
suitable intervals to avoid warping. If required,
the stack shall be adequately raised above
ground level to ensure that it will not be
affected by accumulation of water under it.
The board shall be stacked in a solid block in
a clear vertical alignment. The top sheet of
each stack shall be suitably weighed down to
prevent warping, wherever necessary.
b) Handling — The board shall be unloaded and
stacked with utmost care avoiding damage to
the comers and surface. In case of decorative
plywood and decorative boards, the surfaces
of which are likely to get damaged by dragging
one sheet over another, it is advisable that
these are lifted as far as possible in pairs facing
each other.
8.2.18 Plastic and Rubber Flooring Sheets and Tiles
a) Storage and stacking — Plastic and rubber
sheets have tendency to break-down during
storage. Plastic and rubber sheets shall be
stored according to manufacturer’s
instructions.
The coolest store room available shall be
utilized for the storage of the sheets. The store
rooms where the sheets are stored shall be well
ventilated and direct light should not be
allowed to fall on them.
The sheets shall be stored away from electric
generators, electric motors, switchgears and
other s b electrical equipment as they
produce harmful odour/gases.
Contamination of the sheets with vegetable
and mineral oils; greases; organic solvents;
acids and their fumes; alkalies; dust and grit
shall be prevented. Where greasy
contamination occurs, this shall be removed
immediately with petrol and the sheets and
tiles thoroughly wiped dry and dusted with
chalk.
Undue stretch and strain, kinks, sharp bends
or folds of the sheets and tiles shall be avoided.
In case of long storage, the sheets shall be
turned over periodically and treated with chalk
powder, if necessary.
b) Handling — While handling plastic and
rubber sheets, workers shall lift the sheets and
carry them flat to avoid sharp bends or folds
of the sheets.
8.2.19 Glass Sheets
a) Storage and stacking — The special glasses
shall be stored and handled as per
manufacturer’s instructions. It is important
that all glass sheets whether stored in crates
or not shall be kept dry. Suitable covered
storage space shall be provided for the safe
storage of the glass sheets. The glass sheets
shall be lifted and stored on their long edges
and shall be put into stacks of not more than
25 panes, supported at two points by fillets of
wood at about 300 mm from each end. The
first pane laid in each stack shall be so placed
that its bottom edge is about 25 mm from the
base of the wall or other support against which
the stack rests. The whole stack shall be as
close and as upright as possible. To prevent
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NATIONAL BUILDING CODE OF INDIA 2016
slipping on smooth floor, the floor shall be
covered with gunny bags. The glass sheets of
different sizes, thickness and type shall be
stacked separately. The distance between any
two stacks shall be of the order of 400 mm.
b) Handling — Workers handling glass panes,
waste glass pieces and fibre glass shall be
provided with suitable hand protection. In
removing glass sheets from crates, due care
shall be taken to avoid damages. Glass edges
shall be covered or otherwise protected to
prevent injuries to workers. Special glasses
shall be stored and handled as per
manufacturer’s instructions.
8.2.20 Cast Iron, Galvanized Iron and Asbestos Cement
Pipes and Fittings
a) Storage and stacking - The pipes shall be
unloaded where they are required, when the
trenches are ready to receive them.
Storage shall be provided at the bottom layer
to keep the stack stable. The stack shall be in
pyramid shape or the pipes placed lengthwise
and crosswise in alternate layers. The pyramid
stack is advisable in smaller diameter pipes
for conserving space in storing them. The
height of the stack shall not exceed 1.5 m.
Each stack shall contain only pipes of same
class and size, with consignment or batch
number marked on it with particulars or
suppliers wherever possible.
Cast iron detachable joints and fittings shall
be stacked under cover and separated from
the asbestos cement pipes and fittings.
Rubber rings shall be kept clean, away from
grease, oil, heat and light.
b) Handling — Pipes in the top layer shall be
handled first. At a time only one pipe shall be
handled by two labourers while carrying to
the actual site and shall be carried on
shoulders. Fittings shall be handled
individually.
8.2.21 Polyethylene Pipes
a) Storage and stacking — Black polyethylene
pipes may be stored either under cover or in
the open. Natural polyethylene pipes,
however, should be stored under cover and
protected from direct sunlight.
Coils may be stored either on edge or stacked
flat one on top of the other, but in either case
they should not be allowed to come into
contact with hot water or steam pipes and
should be kept away from hot surface.
Straight lengths should be stored on horizontal
racks giving continuous support to prevent the
pipe taking on a permanent set. Storage of
pipes in heated areas exceeding 27°C should
be avoided.
b) Handling — Removal of pipe from a pile shall
be accomplished by working from the ends of
the pipe.
8.2.22 Unplasticized PVC Pipes
a) Storage and stacking — Pipes should be
stored on a reasonably flat surface free from
stones and sharp projections so that the pipe
is supported throughout its length. The pipe
should be given adequate support at all times.
In storage, pipe racks should be avoided. Pipe
should not be stacked in large piles especially
under warm temperature conditions as the
bottom pipes may distort thus giving rise to
difficulty in jointing. Socket and spigot pipes
should be stacked in layers with sockets placed
at alternate ends of the stacks to avoid lopsided
stacks.
It is recommended not to store a pipe inside
another pipe. On no account should pipes be
stored in a stressed or bend condition or near
a source of heat. Pipes should not be stacked
more than 1 .5 m high. Pipes of different sizes
and classes should be stacked separately.
In tropical conditions, pipes should be stored
in shade. In very cold weather, the impact
strength of PVC is reduced making it brittle.
The ends of pipe should be protected from
abrasion particularly those specially prepared
for jointing either spigot or socket solvent
welded joints or soldered for use with
couplings.
If due to unsatisfactory storage or handling, a
pipe becomes kinked, the damaged portion
should be cut out completely. Kinking is likely
to occur only on very thin walled pipes.
b) Handling — Great care shall be exercised in
handling these pipes in wintry conditions as
these become brittle in very cold weather.
8.2.23 Pipes of Conducting Materials
a) Storage and stacking — Pipes shall be stacked
on solid level sills and contained in a manner
to prevent spreading or rolling of the pipe.
Where quantity storage is necessary, suitable
packing shall be placed between succeeding
layers to reduce the pressure and resulting
spreading of the pile.
In stacking and handling of pipes and other
conducting materials, the following minimum
safety distances shall be ensured from the
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
31
overhead power lines:
1) 11 kV and below : J .40 m
2) Above 1 1 and below 33 kV : 3.60 m
3) Above 33 and below 132 kV : 4.70 m
4) Above 132 and below 275 kV : 5.70 m
5) Above 275 and below 400 kV : 6.50 m
b) Handling — Removal of pipes from a pile
shall be accomplished by working from the
ends of the pipe. During transportation, the
pipes shall be so secured as to ensure against
displacement.
8.2.24 Piles and Poles
a) Storage and stacking — Piles and poles shall
be carefully stacked on solid, level sills so as
to prevent rolling or spreading of the pile.
The storage area shall be maintained free of
vegetation and flammable materials.
b) Handling — When placing piles or poles on
the stack, workers shall work from the ends
of the piles/poles. Similar precautions shall
be observed in removal of piles/poles from
the stack. Tag lines shall be used to control
piles and poles when handling for any purpose.
In stacking and handling of piles and poles, precautions
as laid down in 8.2.18 (a) shall be followed.
8.2.25 Paints, Varnishes and Thinners
a) Storage and stacking — Paints, varnishes,
lacquers, thinners and other flammable
materials shall be kept in properly sealed or
closed containers. The containers shall be kept
in a well ventilated location, free from
excessive heat, smoke, sparks or flame. The
floor of the paint stores shall be made up of
100 mm thick loose sand.
Paint materials in quantities other than
required for daily use shall be kept stocked
under regular storage place.
Where the paint is likely to deteriorate with
age, the manner of storage shall facilitate
removal and use of lots in the same order in
which they are received.
Temporary electrical wirings/fittings shall not
be installed in the paint store. When electric
lights, switches or electrical equipment are
necessary, they shall be of explosion proof
design.
b) Handling — Adequate ventilation to prevent
the accumulation of flammable vapours to
hazardous levels of concentration shall be
provided in all areas where painting is done.
When painting is done in confined spaces where
flammable or explosive vapours may develop, any
necessary heat shall be provided through duct work
remote from the source of flame.
Sources of ignition, such as open flame and exposed
heating elements, shall not be permitted in area or rooms
where spray painting is done nor shall smoking be
allowed there.
Care should be taken not to use any naked flame inside
the paint store. Buckets containing sand shall be kept
ready for use in case of fire. Fire extinguishers when
required shall be of foam type conforming to accepted
standards [7(23)] {see also good practice [7(24)]}.
Each workman handling lead based paints shall be
issued !4 litre milk per day for his personal
consumption.
8.2.26 Bitumen, Road Tar, Asphalt, etc
a) Storage and stacking - Drums or containers
containing all types of bitumen, road tar,
asphalt, etc, shall be stacked vertically on their
bottoms in up to 3 tiers. Leaky drums shall be
segregated. Empty drums shall be stored in
pyramidal stacks neatly in rows.
b) Handling — See 9.13.3.1.2 and 9.13.3.4.
8.2.27 Bituminous Roofing Felts
a) Storage and stacking — Bituminous roofing
felts shall be stored away from other
combustible materials and shall be kept under
shade.
b) Handling — Bituminous roofing felts should
be handled in a manner to prevent cracking
and other damages.
8.2.28 Flammable Materials
a) Storage and stacking — In addition to the
requirements as laid down in 8.1.3, the
following provisions shall also apply:
1) Outdoor storage of drums requires some
care to avoid contamination because
moisture and dirt in hydraulic brake and
transmission fluid, gasoline, or lubricants
may cause malfunction or failure of
equipment, with possible danger to
personnel. The storage area should be free
of accumulations of spilled products,
debris and other hazards.
2) Compressed gases and petroleum
products shall not be stored in the same
building or close to each other. Storage
of petroleum products should be as per
Petroleum Rules, 2002, as amended from
time-to-time.
32
NATIONAL BUILDING CODE OF INDIA 2016
b) Handling — Petroleum products delivered to
the job site and stored there in drums shall be
protected during handling to prevent loss of
identification through damage to drum
markings, tags, etc. Unidentifiable petroleum
products may result in improper use, with
possible fire hazard, damage to equipment or
operating failure.
Workers shall be required to guard carefully against
any part of their clothing becoming contaminated w'ith
flammable fluids. They shall not be allowed to continue
work when their clothing becomes so contaminated.
8.2.29 Water
Water to be stored for construction purposes shall be
stored in proper tanks to prevent any ingress of organic
impurities. The aggregate capacity of storage tanks shall
be determined after taking into account the
requirements of firefighting.
8.2.30 Sanitary Appliances
a) Storage and stacking — Ail sanitary
appliances shall be carefully stored under
cover to prevent damage. When accepting and
storing appliances, consideration shall be
given to the sequence of removal from the
store to the assembly positions. Vitreous
fittings shall be stacked separately from the
metal ones.
b) Handling — Bigger sanitary appliances shall
be handled one at a time. Traps, water seals
and gullies shall be handled separately. While
handling sanitary fittings they shall be free
from any oil spilling, etc. The hands of the
workers shall also be free from any oily
substance. Before lowering the appliances in
their position the supporting brackets,
pedestals, etc, shall be checked for their
soundness and then only the fixtures be
attached.
8.2.31 Other Materials
Polymeric materials such as coatings, sheeting,
reflective surfacing/sheeting, etc, shall be stored as per
the manufacturers’ instructions. Special precautions
shall be taken in case of storage, handling and usage of
toxic materials.
Small articles like screws, bolts, nuts, door and window
fittings, polishing stones, protective clothing, spare
parts of machinery, linings, packings, water supply and
sanitary fittings, and electrical fittings, insulation board,
etc, shall be kept in suitable and properly protected
containers or store rooms. Valuable small materials shall
be kept under lock and key.
8.2.32 Special Considerations
8.2.32.1 Materials constantly in use shall be relatively
nearer to the place of use.
8.2.32.2 Heavy units like precast concrete members
shall be stacked near the hoist or the ramp.
8.2.32.3 Materials which normally deteriorate during
storage shall be kept constantly moving, by replacing
old materials with fresh stocks. Freshly arrived
materials shall never be placed over materials which
had arrived earlier.
8.2.32.4 Appropriate types of fire extinguishers shall
be provided at open sites where combustible materials
are stored and for each storage shed/room where
flammable/combustible materials are stored. For
guidance regarding selection of the appropriate types
of fire extinguishers reference may be made to good
practice [7(24)]. It is desirable that a minimum of two
extinguishers are provided at each such location.
8.2.32.5 Workers handling excavated earth from
foundation, particularly if the site happens to be
reclaimed area or marshy area or any other infected
area, shall be protected against infection affecting their
exposed body portions.
8.2.32.6 House keeping
Stairways, walkways, scaffolds, and access ways shall
be kept free of materials, debris and obstructions. The
engineer-in-charge/the foreman shall initiate and carry
out a programme requiring routine removal of scrap
and debris from scaffolds and walkways.
8.2.32.7 Where stacking of the materials is to be done
on road side berms in the street and other public place,
the owner shall seek permission from the Authority for
such stacking and also for removing the remnants of
the same after the construction is over, so as to avoid
any hazard to the public.
8.3 Unloading Rail/Road Wagons and Motor
Vehicles
8.3.1 Loading and unloading from rail/road wagons
8.3. 1.1 Appropriate warning signals shall be displayed
to indicate that the wagons shall not be coupled or
moved.
8.3. 1.2 The wheels of wagons shall always be sprigged
or chained while the wagons are being unloaded. The
brakes alone shall not be depended upon.
8.3. 1.3 Special level bars shall preferably be used for
moving rail wagons rather than ordinary crow bars.
8.3. 1.4 Where gangplanks are used between wagons
and platforms of piles (heaps), cleats at lower end of
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
33
gangplank, or pin through end of gangplanks, shall be
used to prevent sliding. If gangplank is on a gradient,
cleats or abrasive surface shall be provided for the entire
length.
8. 3. 1.5 When rail/road wagons are being loaded or
unloaded near passageways or walkways, adequate
warning signals shall be placed on each end of the
wagon to warn pedestrians.
8.3.2 Loading and Unloading from Motor Vehicles
8.3.2. 1 The motor vehicles shall be properly blocked
while being loaded or unloaded; brakes alone shall not
be depended upon to hold them.
8. 3.2. 2 When motor vehicles are being loaded or
unloaded near passageways or walkways, adequate
warning signs shall be placed on each end of the vehicle
to warn the pedestrians.
8.3. 2.3 Adequate lighting shall be provided while
loading/unloading.
8.3.3 Handling Heavy/Long Items
8.3.3. 1 Loading and unloading of heavy items, shall,
as far as possible, be done with cranes or gantries. The
workman shall stand clear of the material being moved
by mechanical equipment. The slings and the ropes used
shall be of adequate load carrying capacity, so as not
to give way and result in accidents.
8.3.3. 2 While heavy and long components are being
manually loaded into motor vehicle, wagons, trailer,
etc, either wooden sleepers or steel rails of sufficient
length and properly secured in position shall be put in
a gentle slope against the body of the wagon/vehicle at
3 or 4 places for loading. These long items shall be
dragged, one by one, gently and uniformly along these
supports by means of ropes, being pulled by men with
feet properly anchored against firm surface. As soon
as the items come on the floor of the vehicle, the same
may be shifted by crowbars and other suitable leverage
mechanism, but not by hands to avoid causing accident
to the workers.
8.3.3.3 Similar procedure as outlined under 8.3.3.2 shall
be followed for manual unloading of long or heavy
items.
SECTION 4 SAFETY IN CONSTRUCTION
9 SAFETY IN CONSTRUCTION OF ELEMENTS
OF A BUILDING
9.1 General
9.1.1 The provisions of this section shall apply to the
erection/alteration of the various parts of a building or
similar structure. The construction of the different
elements shall conform to 6.4.
9.1.2 Other Laws
Nothing herein stated shall be construed to nullify any
rules, regulations, safety standards or statutes of the
local state governments or those contained in the
various Acts of the Government of India. The specific
rules, regulations and acts pertaining to the protection
of the public or workers from health and other hazards,
wherever specified by the Local/State Authority or in
the Acts of the Government take precedence over
whatever is herein specified in case of a doubt or
dispute.
9.1.3 Safety Management
9.1.3. 1 The safety of personnel engaged in building
construction should be ensured through a well planned
and well organized mechanism by employing the
guidelines given in good practice [7(12)].
9.1.3.2 Notwithstanding the guidelines given in 9.1.3. 1,
all provisions given in relevant Act/Rules/Regulations
as amended from time to time shall be followed; in this
regard, reference shall also be made to the Building
and other Construction Workers (Regulation of
Employment and Conditions of Service) Act, 1 996 and
the rules/regulations framed thereunder.
9.2 Temporary Construction, Use of Side Walls and
Temporary Encroachments
9.2.1 Temporary Construction
The plans and specifications of temporary
constructions, which are likely to interfere with facilities
or right of way provided by the Authority, shall be
submitted to the Authority for approval showing clearly
the layout, design and construction.
9.2. 1.1 Temporary structure referred to in 9.2.1 shall
apply to the following types of structures :
a) Structures with roof or walls made of straw,
hay, ulugrass, golpatta, hogle, darma, mat,
canvas cloth or other like materials not
adopted for permanent or continuous
occupancy.
b) Site-work sheds, truck-runways, trestles, foot¬
bridges, etc.
9.2.2 For detailed information regarding fire safety
aspects in respect of construction, location,
maintenance and use of temporary structures
[mentioned in 9.2.1.1(a)] including pandals used by
public for outdoor assembly, reference may be made
to good practice [7(25)].
9.2.3 Special permits shall be obtained for the storage
of the materials on side walks and highways. It shall be
ensured that the material dump or the storage shed does
not create a traffic hazard, nor it shall interfere with
the free flow of the pedestrian traffic. Special permits
34
NATIONAL BUILDING CODE OF INDIA 2016
shall also be obtained for the use of water and electricity
from the public facilities. Whenever such utilities are
made use of, adequate safety precautions regarding
drainage and elimination of contamination and hazards
from electricity shall be taken.
9.2.4 In order to ensure safety for the adjoining
property, adequate temporary protective guards are to
be provided. In case these protective devices project
beyond the property, the consent of the Authority and
that of the owner of the adjoining property shall be
obtained.
9.3 Testing
9.3.1 Tests
No structure, temporary support, scaffolding or any
construction equipment during the construction or
demolition of any building or structure shall be loaded
beyond the allowable loads and working stresses as
provided for in Part 6 ‘Structural Design’ of the Code
{see also good practices [7(26)]}.
9.3. 1.1 Whenever any doubt arises about the structural
adequacy of a scaffolding, support or any other
construction equipment, it shall be tested to two and a
half times the superimposed dead and imposed loads
to which the material or the equipment is subjected to
and the member/material shall sustain the test load
without failure if it is to be accepted.
9.3.2 Notwithstanding the test mentioned above, if any
distress in any member is visible, the member shall be
rejected.
9.4 Inspection and Rectification of Hazardous
Defects
9.4.1 Inspection
The Authority shall inspect the construction equipment
and if during the inspection, it is revealed that unsafe/
illegal conditions exist, the Authority shall intimate the
owner and direct him to take immediate remedial
measures to remove the hazard/violation.
9.4.2 Rectification
The owner shall proceed to rectify the defect, hazardous
condition or violation within 24 h of the receipt of the
notice from the Authority. The Authority shall have full
powers to rectify the unsafe condition and all expenses
incurred in this connection is payable by the owner of
the property. Illegal encroachments and non-payment
of money due, in respect of the rectification of unsafe
conditions may vest a lien on the property with the
Authority {see also Part 2 ‘Administration’ of the Code).
9.4.3 When the strength and adequacy of any scaffold
or other construction equipment is in doubt or when
any complaint is made, the Authority shall get the same
inspected before use.
9.5 Foundations
9.5.1 General
The distribution of the supporting foundation shall be
such as to avoid any harmful differential settlement of
the structure. The type and design of the foundation
adopted shall ensure safety to workers during
construction and residents of the neighbouring property.
Sufficient care shall be taken in areas, where withdrawal
of ground water from surrounding areas could result in
damages to such foundations. During the construction
of the foundation, it shall be ensured that the adjoining
properties are not affected by any harmful effects.
9.5.2 Adjoining Properties
The person causing excavation shall, before starting
the work, give adequate notices in writing to the owner
of the adjoining properties, safety of which is likely to
be affected due to excavation. After having given such
notices, wherein details regarding the type of protective
works that are anticipated to be incorporated in the
excavation are shown, written permission shall be
obtained for such excavation from the adjoining
property owners. Where necessary, the person causing
excavation shall make adequate provision to protect
the safety of adjacent property. If on giving such notices
and the precautionary measures having been approved
by the Authority, the adjoining property owner still
refuses to give necessary facilities to the person causing
excavation for protecting/providing both temporary and
permanent supports to such property, the responsibility
for any damage to the adjoining property shall be that
of the adjoining property owner. The person causing
excavation shall be absolved of responsibility for any
loss of property or life in the adjoining property.
9. 5. 2.1 Protection to neighbouring structures and
adjoining services
In driven piles, vibration is set up which may cause
damage to adjoining structures or service lines
depending on the nature of soil condition and the
construction standard of such structures and service
lines. Possible extent of all such damages shall be
ascertained in advance and operation and mode of
driving shall be planned with appropriate measures to
ensure safety.
Wherever in the vicinity of a site where bored or driven
piling works are to be carried out there are old structures
which are likely to be damaged, tell-tales shall be fixed
on such structures to watch their behaviour and timely
precautions taken against any undesirable effect.
In case of bored piles, measures shall be taken to ensure,
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
35
that there is no appreciable movement of soil mass into
the borehole which may cause subsidence to any
existing foundation in the close proximity. In wet holes
where such possibilities are likely to be there the same
shall be minimised by approved technique and the
operation should be planned.
9.5.3 During construction, inspection shall be made by
the engineer-in-charge to ensure that all protective
works carried out to safe-guard the adjoining property
are sufficient and in good order to ensure safety
( see Part 2 ‘Administration’ of the Code).
9.5.4 Before carrying out any excavation work/pile
driving, the position, depth and size of underground
structures, such as water pipes, mains, cables or other
services in the vicinity to the proposed work, may be
obtained from the Authority to prevent accidents to
workers engaged in excavation work and calamities for
the general public.
Prior to commencement of excavation detailed data of
the type of soils that are likely to be met with during
excavation shall be obtained and the type of protective
works by way of shoring timbering, etc, shall be decided
upon for the various strata that are likely to be
encountered during excavation. For detailed information
regarding safety requirements during excavation
reference may be made to good practice [7(20)].
9.6 General Requirements and Common Hazards
During Excavation
9.6.1 Location of Machinery and Tools
Excavating machinery consisting of both heavy and
light types shall be kept back from the excavation site
at a distance which would be safe for such type of
equipment. Heavy equipment, such as excavating
machinery and road traffic shall be kept back from the
excavated sites at a distance of not less than the depth
of trench or at least 6 m for trench deeper than 6 m.
Care shall also be taken to keep excavating tools and
materials far away from the edge of trench to prevent
such items being inadvertently knocked into the trench.
9.6.2 Excavated Materials
Excavated materials shall be kept back from the edges
of the trench to provide clear benn of safe width. Where
this is not feasible, the protective works designed for
the trenches shall take into consideration, the additional
load due to overburden of materials.
9.6.2. 1 Other surcharges
Proximity of buildings, piles of lumber, crushed rocks,
sam and other construction materials, large trees, etc,
may impose surcharges on the side of the trench to cause
sliding, etc. Under these conditions additional
protective works shall be provided to support the sides
of the trench.
9.6.3 Type of Strata
Adequate precautions, depending upon the type of strata
met with during excavation (like quick sand, loose fills
and loose boulder) shall be taken to protect the workers
during excavation. Effect of climatic variations and
moisture content variations on the materials under
excavation shall be constantly watched and precautions
taken, where necessary, immediately to prevent
accidents at work site.
9.6.4 Overhang and Slopes
During any excavation, sufficient slopes to excavated
sides by way of provision of steps or gradual slopes
shall be provided to ensure the safety of men and
machine working in the area.
9.6.5 Blasting for foundation of building is prohibited
unless special permission is obtained from the
Authority. Where blasting technique has to be resorted
to, prior inspection for the stability of slopes shall be
carried out. After blasting, overhangs or loose boulders
shall be cleared by expert workers carrying out blasting
prior to continuation of the excavation by normal
working parties.
9. 6. 5.1 Burrowing or mining or what is known as
‘gophering’ shall not be allowed. In any trench where
such methods have been followed, the cavities felt shall
be eliminated by cutting back the bare slope before
removing any further materia! from the section of the
trench.
9.6.6 Health Hazards
Where gases or fumes are likely to be present in
trenches, sufficient mechanical ventilation, to protect
the health and safety of persons working there, shall be
provided. If necessary, the personnel working there,
shall be provided with respiratory protective equipment
when work in such unhealthy conditions has to be
carried out. The precautionary measures provided shall
be inspected by the local health authorities prior to
commencement of the work.
9.6.7 Safety of Materials
Materials required for excavation, like ropes, planks
for gangways and walkways, ladders, etc, shall be
inspected by the engineer-in-charge who shall ensure
that no accident shall occur due to the failure of such
materials {see Part 5 ‘Building Materials’ of the Code).
9.6.8 Fencing and Warning Signals
Where excavation is going on, for the safety of public
and the workers, fencing shall be erected, if there is
likelihood of the public including cattle frequenting the
area. Sufficient number of notice boards and danger
sign lights shall be provided in the area to avoid any
36
NATIONAL BUILDING CODE OF INDIA 2016
member of public from inadvertently falling into the
excavation. When excavations are being done on roads,
diversion of the roads shall be provided with adequate
notice board and lights indicating the diversion well
ahead. Where necessary, recourse may be had for
additional precautionary measures by way of watchmen
to prevent accident to the general public, especially
during hours of darkness.
9.6.9 Effect of Freezing and Thawing
Due to expansion of water when freezing, rock
fragments, boulders, etc, are frequently loosened.
Therefore, the side walls of the excavation shall be
constantly watched for signs of cracks during a thaw.
When depending in whole or in part on freezing to
support the side walls, great care shall be taken during
thaws to provide suitable bracing or remedy the
condition by scaling of the loose material from the sides.
9.6.10 Vibrations from Nearby Sources
Vibration due to adjacent machinery, vehicles, rail¬
roads, blasting, piling and other sources require
additional precautions to be taken.
9.6.11 Precautions While Using Petroleum Powered
Equipment
At the site of excavation, where petroleum powered
equipment is used, petroleum vapours are likely to
accumulate at lower levels and may cause fire explosion
under favourable circumstances. Care should, therefore,
be taken to avoid all sources of ignition in such places.
9.7 Piling and Other Deep Foundations
9.7.1 General
9.7.1. 1 Safety programme
All operations shall be carried out under the immediate
charge of a properly qualified and competent foreman
who shall also be responsible for the safety
arrangements of the work.
9. 7. 1.2 For work during night, lighting of at least
100 lux intensity shall be provided at the work site.
9. 7. 1.3 Barricading/fencing shall be provided, wherever
necessary, around the working area or the watchmen
provided to prevent onlookers from trespassing into
the construction sites. In case of digging a bore hole,
precautions shall be taken that it is properly barricaded
and is not left open to avoid accidental fall into the
bore well.
9. 7. 1.4 The working area shall be investigated to
ascertain the presence of any buried obstruction and
actual position of all service lines passing through the
work site shall be known before the work commences.
Particular attention shall be given in case live electrical
cables pass underground, which may interfere within
the depth of the foundation.
9. 7. 1.5 The safety provisions shall be brought to the
notice of all concerned and matters needing special
attention shall be displayed at a prominent place at the
work spot.
9.7. 1.6 All necessary personal protective equipment like
full body harnesses, safety helmets and safety shoes,
as considered suitable, shall be kept available for the
use of persons employed on the site and maintained in
condition suitable for immediate use.
9.7.1. 7 A first-aid kit shall be maintained at the site
near the place of work, to comply with the requirements
and provisions for the work.
9.7.1. 8 Those engaged in mixing and stacking of cement
bags or any other material injurious to human body
shall be provided with protective wear suitable for the
purpose. Welders engaged in the work of welding shall
use welding goggles/shields, helmets and gloves.
9. 7. 1.9 Every crane driver or hoisting appliance
operator shall be competent to the satisfaction of the
engineer-in-charge and no person under the age of
21 years should be in-charge of any hoisting machine
including any scaffolding winch, or give signals to
operator. Crane driver and hoisting appliance operator
shall posses the knowledge of inherent risks involved
in the operation of lifting appliances by undergoing a
formal training at any institution of national importance
acceptable to the employer and is medically examined
periodically including in compliance to the requirement
as may be specified in the Building and other
Construction Workers ’ (Regulation of Employment and
Conditions of Service Central) Rules , 1998.
9.7.1.10 Working in compressed air, in case of deep
foundations, requires several precautions to be observed
to safeguard the workers against severe hazards to life,
compressed air disease and related ailments. For
detailed information regarding safety requirements,
reference may be made to good practice [7(27)].
9.7.2 Piling Rig
9.7.2. 1 There are numerous types of piling rigs in piling
work, depending on the need for the site conditions.
While utilizing specialized rigs the instructions issued
by the suppliers shall be kept in view.
9. 7.2. 1.1 Pile drivers shall not be erected in dangerous
proximity to electric conductors.
9.7.2. 1.2 If two pile drivers are erected at one place
these shall be separated by a distance at least equal to
the longest leg in either rig.
9. 7. 2. 2 The frame of any rig shall be structurally safe
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
37
for all anticipated dead, live or wind loads. Whenever
there is any doubt about the structural strength, suitable
test shall be carried out by the foreman and the results
of the test recorded. No pile-driving equipment shall
be taken into use until it has been inspected and found
to be safe.
9. 7.2.3 Pile drivers shall be firmly supported on heavy
timber sills, concrete beds or other secure foundation.
If necessary, to prevent danger, pile drivers shall be
adequately guyed.
When the rig is not in use, extra precautionary measures
for stability, such as securing them with minimum four
guys, shall be adopted to prevent any accidents due to
wind, storm, gales and earthquake.
9.7.2.4 Access to working platforms and the top pulley
shall be provided by ladders. Working platforms shall
be protected against the weather.
9.7.2.4.1 In tall driven piling rigs or rigs of similar
nature where a ladder is necessary for regular use, the
ladder shall be securely fastened and extended for the
full height of the rig. The ladder shall also be maintained
in good condition at all times.
9.7.2.5 Exposed gears, fly wheels, etc, shall be fully
enclosed. Boilers, hoisting drums and brakes shall be
kept in good condition and sheltered from weather,
wherever possible.
9.7.2.6 Pile driving equipment in use shall be inspected
by a competent engineer at regular intervals not
exceeding three months. Also a register shall be
maintained at the site of work for recording the results
of such inspections. Pile lines and pulley blocks shall
be inspected by the foreman before the beginning of
each shift for any excess wear or any other defect.
9. 7. 2. 6.1 Defective parts of pile drivers, such as
sheaves, mechanism slings and hose shall be repaired
by only competent person and duly inspected by
foreman-in-charge of the rig and the results recorded
in the register. No steam or air equipment shall be
repaired while it is in operation or under pressure.
Hoisting ropes on pile drivers shall be made of
galvanized steel.
9. 1.2.1 All bolts and nuts which are likely to be loosened
due to vibration during pile driving shall be checked
regularly and tightened.
9. 7.2. 8 Steam and air lines shall be controlled by easily
accessible shut-off valves. These lines shall consist of
armoured hose or its equivalent. The hose of steam and
air hammers shall be securely lashed to the hammer so
as to prevent it from whipping if a connection breaks.
Couplings of sections of hose shall be additionally
secured by ropes or chains.
9.1. 2.9 When not in use, the hammer shall be in dropped
position and shall be held in place by a cleat, timber or
any other suitable means.
9.7.2.10 For every hoisting machine and for every chain
ring hook, shackle, swivel and pulley block, used in
hoisting or as means of suspension, the safe working
loads shall be ascertained. In case of doubt actual testing
shall be carried out and the working load shall be taken
as half of the tested load. Every hoisting machine and
all gears referred to above shall be plainly marked with
the safe working load. In case of a hoisting machine
having a variable safe working load, each safe working
load together with the conditions under which it is
applicable shall be clearly indicated. No part of any
machine or any gear shall be loaded beyond the safe
working load except for the purpose of testing.
All hoisting appliances should be fitted with automatic
safe load indicator, boom angle indicator, swing alarm,
back horn, over lift boom alarm. A register shall be
maintained containing a system of identification of all
tools and tackles, their date of purchase, safe working
load and date of examination by competent person. All
loads shall have tag-lines attached in order to ensure
that the load can be controlled at all times.
9.7.2.11 Motor gearing, transmission, electrical wiring
and other dangerous parts of hoisting appliances should
be provided with efficient safeguards. Hoisting
appliances shall be provided with such means as will
reduce, to the minimum, the risk of accidental descent
of the load and adequate precautions shall be taken to
reduce to the minimum, the risk of any part of
suspended load becoming accidentally displaced. When
workers are employed on electrical installations which
are already energized, insulating mats and wearing
apparel, such as gloves, etc, as may be necessary, shall
be provided. Sheaves on pile drivers shall be guarded
so that workers may not be drawn into them.
When loads have to be inclined, they shall be
adequately counter-balanced and the tilting device shall
be secured against slipping.
9.7.2.12 Adequate precautions shall be taken to prevent
a pile driver from overturning, if a wheel breaks.
9.7.2.13 Adequate precautions shall be taken by
providing stirrups or by other effective means, to
prevent the rope from coming out of the top pulley or
wheel.
9.7.2.14 Adequate precautions shall be taken to prevent
the hammer from missing the pile.
9.7.2.15 If necessary to prevent danger, long piles and
heavy sheet piling should be secured against falling.
9.7.2.16 Wherever steam boilers are used, the safety
regulations of boiler shall be strictly followed and safety
38
NATIONAL BUILDING CODE OF INDIA 2016
valves shall be adjusted to 0.07 N/mm2 in excess of
working pressure accurately.
9.7.2.17 Where electricity is used as power for piling
rig, only armoured cable conforming to the relevant
Indian Standard shall be used and the cable shall be
thoroughly waterproofed.
9.7.3 Operation of Equipment
9.7.3. 1 Workers employed in the vicinity of pile drivers
shall wear helmets conforming to accepted
standard [7(28)].
9.7.3.2 Piles shall be prepared at a distance at least
equal to twice the length of the longest pile from the
pile driver.
9.7.3.3 Piles being hoisted in the rig should be so slung
that they do not have to be swung round, and may not
inadvertently, swing or whip round. A hand rope shall
be fastened to a pile that is being hoisted to control its
movement. While a pile is being guided into position
in the leads, workers shall not put their hands or arms
between the pile and the inside guide or on top of the
pile, but shall use a rope for guiding.
9.7.3.4 While a pile is being hoisted all workers not
actually engaged in the operation shall keep at a distance
which ensures safety. Piles shall not be slewed over
public areas without stopping the pedestrians and road
traffic first.
9.7.3.5 Before a wood pile is hoisted into position it
shall be provided with an iron ring or cap over the
driving end to prevent brooming.
9.7.3. 6 When creosoted wood piles are being driven,
adequate precautions shall be taken, such as the
provision of personal protective equipment and barrier
creams to prevent workers receiving eye or skin injuries
from splashes of creosote.
9.7.3. 7 When piles are driven at an inclination to the
vertical, if necessary to prevent danger, these should
rest in a guide.
9. 7.3. 8 No steam or air line shall be blown down until
all workers are at a safe distance.
9.7.4 Sheet Piling
9.7.4. 1 If necessary to prevent danger from wind or
other sources, a hand rope shall be used to control the
movement of steel sheet sections that are being
transported.
9. 7. 4.2 Workers who have to sit on a steel sheet section
to interlock sheets shall be provided with stirrups or
other devices to afford them a safe seat. Workers shall
not stand or sit on sheet piling while it is being released
from the slings, lowered or moved into position.
9. 7.4.3 Workers handling sheets should wear gloves.
9. 7. 4. 4 If necessary to prevent danger from
displacement by the current, steel sheet sections shall
be braced until they are firmly in position. If necessary
to prevent danger from undercutting of the cofferdam
by the current a substantial berm shall be installed
upstream.
9. 7. 4.5 Adequate pumping facilities shall be available
at cofferdams to keep them clear of water. Also adequate
means of escape, such as ladders and boats shall be
provided at cofferdams for the protection of workers
in case of flooding.
9. 7.4. 6 Adequate supplies of life-saving equipment
shall be provided for workers employed on cofferdams.
9.7.4. 7 When sheet sections are being removed, their
movements shall be controlled by cables or other
effective means.
9.8 Walls
9.8.1 General
Depending on the type of wall to be constructed the
height of construction per day shall be restricted to
ensure that the newly constructed wall does not come
down due to lack of strength in the lower layers.
Similarly, in long walls adequate expansion/crumple
joints shall be provided to ensure safety.
9.8.2 Scaffold
Properly designed and constructed scaffolding built by
competent workers shall be provided during the
construction of the walls to ensure the safety of workers.
The scaffolding may be of timber, metal or bamboo
sections and the materials in scaffolding shall be
inspected for soundness, strength, etc, at site by the
engineer-in-charge prior to erection of scaffolds. Steel
scaffolds intended for use in normal building
construction work shall conform to accepted standard
[7(29)]. Bamboo and timber scaffolds shall be properly
tied to the junctions with coir ropes of sufficient strength
or mechanical joints to ensure that joints do not give
way due to the loa^ of workers and material. Joining
the members of scaffolds only with nails shall be
prohibited as they are likely to get loose under normal
weathering conditions. In the erection or maintenance
of tall buildings, scaffoldings shall be of non¬
combustible material especially when the work is being
done on any building in occupation. After initial
construction of the scaffolding, frequent inspections of
scaffolding shall be carried out regularly. The platforms,
gangways and runways provided on the scaffoldings
shall be of sufficient strength and width to ensure safe
passage for the workers working on the scaffolding.
The joints provided in these gangways, platforms, etc,
shall be such as to ensure a firm foot-hold to the
workers. Where necessary, cross bars shall be provided
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
39
to the full width of gangway or runway to facilitate
safe walking. For detailed information regarding safety
requirements for erection, use and dismantling of
scaffolds, reference may be made to good practices
[7(30)].
9.8.2. 1 The engineer-in-charge shall ensure by frequent
inspections that gangways of scaffolding have not
become slippery due to spillage of material. Loose
materials shall not be allowed to remain on the
gangways. Where necessary, because of height or
restricted width, hand-rails shall be provided on both
sides. Workers shall not be allowed to work on the
scaffolding during bad weather and high winds.
9.8. 2. 2 In the operations involved in the erection or
maintenance of outside walls, fittings, etc, of tall
buildings, it is desirable to use one or more net(s) for
the safety of the workers when the workers are required
to work on scaffoldings.
9,8.3 Ladders
All ladders shall be constructed of sound materials and
shall be capable of carrying their intended loads safely.
The ladders shall have not only adequate strength but
rigidity as well. If a ladder shows tendency to spring, a
brace shall be attached to its middle and supported from
some other non-yielding fixed object. No ladder having
a missing or defective rung or one which depends for
its support solely on nails, shall be used. Ladders shall
not be used as guys, braces or skids or for any other
purpose for which they are not intended. They shall
not be used in horizontal position as runways. They
shall not be overcrowded. Wherever possible, ladders
shall not be spliced. Where splicing is unavoidable, it
shall be done only under the supervision of engineer-
in-charge. Ladders leading to landings or walkways
shall extend at least 1 m above the landing and shall be
secured at the upper end. To prevent slipping, a ladder
shall be secured at the bottom end. If this cannot be
done, a person shall be stationed at the base whenever
it is in use. As a further precaution, the pitch at which a
lean-to-ladder is used shall be suffi mat the horizontal
distance of its foot from the vertical plane of its top
shall be not more than one quarter of its length. If the
surface of the floor on which the ladder rests is smooth
or sloping, the ladder shall be provided with non-slip
bases. If the use of a ladder is essential during strong
winds, it shall be securely lashed in position. No ladder
shall be placed or leant against window pane, sashes
or such other unsafe or yielding objects, nor placed in
front of doors opening towards it. If set up in driveways,
passageways or public walkways, it shall be protected
by suitable barricades. When ascending or descending,
the user shall face the ladder, use both his hands and
place his feet near the ends of the rungs rather than
near the middle. It is dangerous to lean more than 30 cm
to side in order to reach a larger area from a single
setting of the ladder. Instead, the user shall get down
and shift the ladder to the required position.
Metal ladders shall not be used around electrical
equipment or circuits of any kind where there is a
possibility of coming in contact with the current. Metal
ladders shall be marked with signs reading ‘CAUTION —
DO NOT USE NEAR ELECTRICAL EQUIPMENT’.
Wooden ladders shall be inspected at least once in a
month for damage and deterioration. Close visual
inspection is recommended in preference to load
testing. This condition is particularly applicable to rope
and bamboo ladders wherein fraying of ropes and
damage to bamboo is likely to occur due to materials
falling on them. When a ladder has been accidentally
dropped it shall be inspected by the engineer-in-charge
prior to re-use. Overhead protection shall be provided
for workers under ladder. For detailed information
regarding safety requirements for use of ladders,
reference may be made to good practice [7(31)].
9.8.4 Opening in Walls
Whenever making of an opening in the existing wall is
contemplated, adequate supports against the collapse
or cracking of the wall portion above or roof or
adjoining walls shall be provided.
9. 8.4.1 Guarding of wall openings and holes
Wall opening barriers and screens shall be of such
construction and mounting that they are capable of
withstanding the intended loads safely. For detailed
information reference may be made to good practice
[7(32)]. Every wall opening from which there is a drop
of more than 1 200 mm shall be guarded by one of the
following:
a) Rail, roller, picket fence, half door or
equivalent barrier — The guard may be
removable but should preferably be hinged or
otherwise mounted so as to be conveniently
replaceable. Where there is danger to persons
working or passing below on account of the
falling materials, a removable toe board or the
equivalent shall also be provided. When the
opening is not in use for handling materials,
the guards shall be kept in position regardless
of a door on the opening. In addition, a grab
handle shall be provided on each side of the
opening. The opening should have a sill that
projects above the floor level at least 25 mm.
b) Extension platform, into which materials may
be hoisted for handling, shall be of full length
of the opening and shall have side rails or
equivalent guards.
9. 8. 4.2 Every chute wall opening from which there is a
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NATIONAL BUILDING CODE OF INDIA 2016
drop of more than 1 200 mm shall be guarded by one
or more of the barriers specified in 9.8.4.1 or as required
by the conditions.
9.8.5 Projection from Walls
Whenever projections cantilever out of the walls,
temporary formwork shall be provided for such
projections and the same shall not be removed till walls
over the projecting slabs providing stability load against
overturning are completely constructed.
9.9 Common Hazards During Walling
9.9.1 Lifting of Materials for Construction
Implements used for carrying materials to the top of
scaffoldings shall be of adequate strength and shall not
be overloaded during the work. Where workers have
to work below scaffoldings or ladder, overhead
protection against the falling materials shall be
provided. Care shall be taken in carrying large bars,
rods, etc, during construction of the walls to prevent
any damage to property or injury to workers.
9.9.2 Haulage of Materials
9.9.2. 1 In case of precast columns, steel beams, etc,
proper precautions shall be taken to correctly handle,
use and position them with temporary arrangement of
guys till grouting of the base.
9. 9.2.2 Manila or sisal rope shall not be used in rainy
season for hoisting of heavy materials as they lose their
strength with alternate wetting and drying.
9.9.3 Electical Hazards
No scaffolding, ladder, working platform, gangway
runs, etc, shall exist within 3 m from any uninsulated
electric wire.
9.9.4 Fire Hazards
Gangways and the ground below the scaffolding shall
be kept free from readily combustible materials
including waste and dry vegetation at all times.
Where extensive use of blow torch or other flame is
anticipated scaffoldings, gangways, etc, shall be
constructed with fire resistant materials. A portable dry
powder extinguisher of 3 kg capacity shall be kept
handy.
9.9.5 Mechanical Hazards
Care shall be taken to see that no part of scaffolding or
walls is struck by truck or heavy moving equipment
and no materials shall be dumped against them to
prevent any damage. When such scaffoldings are in or
near a public thoroughfare, sufficient warning lights
and boards shall be provided on the scaffoldings to
make them clearly visible to the public.
9.9.6 Fragile Materials
During glazing operations, adequate precautions shall
be taken to ensure that the fragments of fragile materials
do not cause any injury to workers or general public in
that area by way of providing covering to such material,
side protection at work site. etc.
9.10 Roofing
9.10.1 Prevention of accidental falling of workers
during the construction of roofs shall be ensured by
providing platforms, catch ropes, etc. If the materials
are to be hoisted from the ground level to the roof level,
adequate precautions shall be taken by way of correct
technique of handling, hoists of sufficient strength to
cater for the quantity of stores to be hoisted and
prevention of overloading such hoists or buckets,
prevention of overturning of hoists or buckets. Where
in a multi-storeyed building, the floor of one storey is
to be used for storage of materials for the construction
of roofs, it shall be ensured that the quantum of stores
kept on the floor along with the load due to personnel
engaged in the construction work shall not exceed the
rated capacity of the floors.
9.10.2 While roofing work is being done with
corrugated galvanized iron or asbestos cement sheets,
it shall be ensured that joints are kept secured in position
and do not slip, thus causing injury to workers. Workers
should not be allowed to walk on asbestos cement sheets
but should be provided with walking boards. While
working with tiles, it shall be ensured that they are not
kept loose on the roof site resulting in falling of tiles
on workers in lower area. In slopes of more than 30° to
the horizontal, the workers shall use ladders or other
safety devices to work on the roof.
9.10.3 If any glass work is to be carried out in the roof,
it shall be ensured that injury to passerby due to
breaking of glass is prevented. During wet conditions,
the workers shall be allowed to proceed to work on a
sloping roof, only if the engineer-in-charge has satisfied
himself that the workers are not likely to slip due to
wet conditions.
9.10.4 Flat Roof
In any type of flat roof construction, any formwork
provided shall be properly designed and executed to
ensure that it does not collapse during construction.
During actual construction of roof, frequent inspection
of the formwork shall be carried out to ensure that no
damage has occurred to it.
9.10.5 While using reinforcement in roofs, it shall be
ensured that enough walking platforms are provided in
the reinforcement area to ensure safe walking to the
concreting area. Loose wires and unprotected rod ends
shall be avoided.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
41
9.10.6 Guarding of Floor Openings and Floor Holes
9.10.6.1 Every temporary floor opening shall have
railings, or shall be constantly attended by someone.
Every floor hole into which persons can accidentally
fall shall be guarded by either,
a) a railing with toe board on all exposed sides;
or
b) a floor hole cover of adequate strength and it
should be hinged in place. When the cover is
not in place, the floor hole shall be constantly
attended by someone or shall be protected by
a removable railing.
9.10.6.2 Every stairway floor opening shall be guarded
by a railing on all exposed sides, except at entrance to
stairway. Every ladder way floor opening or platform
shall be guarded by a guard railing with toe board on
all exposed sides (except at entrance to opening), with
the passage through the railing either provided with a
swinging gate or so offset that a person cannot walk
directly into the opening.
9.10.6.3 Guarding of open-side floors and platform
Every open-sided floor or platform 1 200 mm or more
above adjacent floor or ground level shall be guarded
by a railing (or the equivalent) on all open sides, except
where there is entrance to ramp, stair-way, or fixed
ladder. The railing shall be provided with a toe board
beneath the open sides wherever,
a) persons may pass;
b) there is moving machinery; or
c) there is equipment with which falling materials
could create a hazard.
For detailed information, reference may be made to
good practice [7(32)].
9.11 Additional Safety Requirements for Erection
of Concrete Framed Structures (High-Rise
Buildings)
9.11.1 Handling of Plant
9.11.1.1 Mixers
All gears, chains and rollers of mixers shall be properly
guarded. If the mixer has a charging skip the operator
shall ensure that the workers are out of danger before
the skip is lowered. Railings shall be provided on the
ground to prevent anyone walking under the skip while
it is being lowered.
All cables, clamps, hooks, wire ropes, gears and
clutches, etc, of the mixer, shall be checked and cleaned,
oiled and greased, and serviced once a week. A trial
run of the mixer shall be made and defects shall be
removed before operating a mixer.
When workers are cleaning the inside of the drums,
operating power of the mixer shall be locked in the off
position and all fuses shall be removed and a suitable
notice hung at the place.
9.11.1.2 Cranes
Crane rails where used shall be installed on firm ground
and shall be properly secured. In case of tower cranes,
it shall be ensured that the level difference between the
two rails remains within the limits prescribed by the
manufacturer to safeguard against toppling of the crane.
Requirements for tower cranes as given in 7.3 shall
also be complied with.
Electrical wiring which can possibly touch the crane
or any member being lifted shall be removed, or made
dead by removing the controlling fuses and in their
absence controlling switches.
All practical steps shall be taken to prevent the cranes
being operated in dangerous proximity to a live
overhead power line. In particular, no member of the
crane shall be permitted to approach within the
minimum safety distances as laid down in 8.2.23 (a).
If it becomes necessary to operate the cranes with
clearances less than those specified above, it shall be
ensured that the overhead power lines shall invariably
be shut off during the period of operation of cranes.
Location of any underground power cables in the area
of operation shall also be ascertained and necessary
safety precautions shall be taken.
Cranes shall not be used at a speed which causes the
boom to swing.
A crane shall be thoroughly examined at least once in a
period of 6 months by a competent person who shall
record a certificate of the check.
The operator of the crane shall follow the safe reach of
the crane as shown by the manufacturer.
No person shall be lifted or transported by the crane
on its hook or boom.
Toe boards and limit stops should be provided for wheel
barrows on the loading/unloading platforms. Material
should be loaded securely with no projections.
Concrete buckets handled by crane or overhead
cableway shall be suspended from deep throated hooks,
preferably equipped with swivel and safety latch. In
the concrete buckets, both bottom drop type and side
drop type, closing and locking of the exit door of the
bucket shall always be checked by the man-in-charge
of loading concrete in the bucket to avoid accidental
opening of the exit door and consequent falling of
concrete.
Interlocking or other safety devices should be installed
42
NATIONAL BUILDING CODE OF INDIA 2016
at all stopping points of the hoists. The hoists shaft
way should be fenced properly.
When the bucket or other members being lifted are out
of sight of the crane operator, a signalman shall be
posted in clear view of the receiving area and the crane
operator.
A standard code of hand signals shall be adopted in
controlling the movements of the crane, and both the
driver and the signaller shall be thoroughly familiar
with the signals.
The driver of the crane shall respond to signals only
from the appointed signaler but shall obey stop signal
at any time no matter who gives it.
If a travelling gantry crane is operating over casting
beds, a warning signal which sounds automatically
during travel should be provided to avoid accidents to
workers crossing or standing in the path of the moving
loads.
9.11.1.3 Trucks
When trucks are being used on the site, traffic problems
shall be taken care of. A reasonably smooth traffic
surface shall be provided. If practicable, a loop road
shall be provided to permit continuous operation of
vehicles and to eliminate their backing. If a continuous
loop is not possible, a turnout shall be provided.
Backing operations shall be controlled by a signalman
positioned so as to have a clear view of the area behind
the truck and to be clearly visible to the truck driver.
Movement of workers and plant shall be routed to avoid
crossing, as much as possible, the truck lanes.
9.11.1.4 Concrete pumps (Air compressor operated)
Safety requirements in accordance with good practice
[7(33)] shall be followed.
9.11.2 Formwork
9.11.2.1 Formwork shall be designed after taking into
consideration spans, setting temperature of concrete,
dead load and working load to be supported and safety
factor for the materials used for formwork {see also
with good practice [7(26)]}.
9.11.2.2 All timber formwork shall be carefully
inspected before use and members having cracks and
excessive knots shall be discarded.
9.11.2.3 As timber centering usually takes an initial set
when vertical load is applied, the design of this
centering shall make allowance for this factor.
9.11.2.4 The vertical supports shall be adequately
braced or otherwise secured in position that these do
not fall when the load gets released or the supports are
accidently hit.
9.11.2.5 Tubular steel centering shall be used in
accordance with the manufacturer’s instructions. When
tubular steel and timber centering is to be used in
combination necessary precautions shall be taken to
avoid any unequal settlement under load.
9.11.2.6 A thorough inspection of tubular steel centering
is necessary before its erection and members showing
evidence of excessive resting, kinks, dents or damaged
welds shall be discarded. Buckled or broken members
shall be replaced. Care shall also be taken that locking
devices are in good working order and that coupling
pins are effectively aligned to frames.
9.11.2.7 After assembling the basic unit, adjustment
screws shall be set to their approximate final adjustment
and the unit shall be level and plumb so that when
additional frames are installed the tower shall be in
level and plumb. The centering frames shall be tied
together with sufficient braces to make a rigid and solid
unit. It shall be ensured that struts and diagonals braces
are in proper position and are secured so that frames
develop full load carrying capacity. As erection
progresses, all connecting devices shall be in place and
shall be fastened for full stability of joints and units.
9.11.2.8 In case of timber posts, vertical joints shall be
properly designed. The connections shall normally be
with bolts and nuts. Use of rusted or spoiled threaded
bolts and nuts shall be avoided.
9.11.2.9 Unless the timber centering is supported by a
manufacturer’s certificate about the loads it can stand,
centering shall be designed by a competent engineer.
9.11.2.10 Centering layout shall be made by a qualified
engineer and shall be strictly followed. The bearing
capacity of the soil shall be kept in view for every
centering job. The effect of weather conditions as dry
clay may become very plastic after a rainfall and show
marked decrease in its bearing capacity.
9.11.2.11 Sills under the supports shall be set on firm
soil or other suitable material in a pattern which assures
adequate stability for all props. Care shall be taken not
to disturb the soil under the supports. Adequate drainage
shall be provided to drain away water coming due to
rains, washing of forms or during the curing of the
concrete to avoid softening of the supporting soil strata.
9.11.2.12 All centering shall be finally, inspected to
ensure that,
a) footings or sills under every post of the
centering are sound.
b) all lower adjustment screws or wedges are
sung against the legs of the panels.
c) all upper adjustment screws or heads of jacks
are in full contact with the formwork.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
43
d) panels are plumb in both directions.
e) all cross braces are in place and locking
devices are in closed and secure position.
f) In case of Chhajas and balconies, the props
shall be adequate to transfer the load to the
supporting point.
9.11.2.13 During pouring of the concrete, the centering
shall be constantly inspected and strengthened, if
required, wedges below the vertical supports tightened
and adjustment screws properly adjusted as necessary.
Adequate protection of centering shall be secured from
moving vehicles or swinging loads.
While pouring concrete, it should be placed in such a
manner that the load should be transmitted to the
support of formwork uniformly without causing high
eccentric load.
Caution shall be exercised to avoid heap storage of
bricks/sand in roof/floor slab as it may lead to failure
of slab.
9.11.2.14 Forms shall not be removed earlier than as
laid down in the specifications and until it is certain
that the concrete has developed sufficient strength to
support itself and all loads that will be imposed on it.
Only workers actually engaged in removing the
formwork shall be allowed in the area dunng these
operations. Those engaged in removing the formwork
shall wear helmets, gloves and heavy soled shoes and
approved safety belts if adequate footing is not provided
above 2 m level. While cutting any tying wires in
tension, care shall be taken to prevent backlash which
might hit a workman.
9.11.2.14.1 The particular order in which the supports
are to be dismantled should be followed according to
the instructions of the site engineer.
9.11.3 Ramps and Gangways
9.11.3.1 Ramps and gangways shall be of adequate
strength and evenly supported. They shall either have
a sufficiently flat slope or shall have cleats fixed to the
surface to prevent slipping of workers. Ramps and
gangways shall be kept free from grease, mud, snow or
other slipping hazards or other obstructions leading to
tripping and accidental fall of a workman.
9.11.3.1.1 Ramps and gangways meant for transporting
materials shall have even surface and be of sufficient
width and provided with skirt boards on open sides.
9.11.4 Materials Hoists
9.11.4.1 The hoist should be erected on a firm base,
adequately supported and secured. All materials
supporting the hoist shall be appropriately designed
and strong enough for the work intended and free from
defects.
9.11.4.2 The size of the drum shall match the size of
the rope. Not less than two full turns of rope shall remain
on the drum at all times. Ropes shall be securely
attached to the drum.
9.11.4.3 All ropes, chains and other lifting gear shall
be properly made of sound materials, free from defects
and strong enough for the work intended. They shall
be examined by a competent person who shall clearly
certify the safe working load on each item and the
system.
9.11.4.4 Hoistways shall be protected by a substantial
enclosure at ground level, at all access points and
wherever persons may be struck by any moving part.
9.11.4.5 Gates at access points should be at least 2 m
high, wherever possible. Gates shall be kept closed at
all times except when required open for immediate
movement of materials at that landing place.
9.11.4.6 All gates shall be fitted with electronic or
mechanical interlocks to prevent movement of the hoist
in the event of a gate being opened.
9.11.4.7 Winches used for hoists shall be so constructed
that a brake is applied when the control lever or switch
is not held in the operating position (dead-man’s
handle).
9.11.4.8 The hoist tower shall be tied to a building or
structure at every floor level or at least every 3 m. The
height of the tower shall not exceed 6 m after the last
tie or a lesser height as recommended by the
manufacturer. All ties on a hoist tower shall be secured
using right angled couples.
9.11.4.9 The hoist shall be capable of being operated
only from one position at a time. It shall not be operated
from the cage. The operator shall have a clear view of
all levels or, if he has not, a clear and distinct system of
signaling shall be employed.
9.11.4.10 All hoist platform shall be fitted with guards
and gates to a height of at least 1 m, to prevent materials
rolling/falling from the platform.
9.11.4.11 Where materials extend over the height of
the platform guards, a frame shall be fitted and the
materials secured to it during hoisting/lowering. Care
should be taken to ensure that neither the frame nor
materials interfere or touch any part of the hoisting
mechanism.
9.11.4.12 The platfonn of a goods hoist shall carry a
notice stating,
a) the safe working load; and
b) that passengers shall not ride on the hoist.
9.11 .4.13 All hoist operators shall be adequately trained
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and competent, and shall be responsible for ensuring
that the hoist is not overloaded or otherwise misused.
9.11.4.14 All hoists shall be tested and thoroughly
examined by a competent person before use on a site,
after substantial alteration, modification or repair of
hoists, and at least every 6 months.
9.11.4.15 Every hoist shall be inspected at least once
each week by a competent person and a record of these
inspections kept.
9.11.5 Prestressed Concrete
9.11.5.1 In pre-stressing operations, operating,
maintenance and replacement instructions of the
supplier of the equipment shall be strictly adhered to.
9.11.5.2 Extreme caution shall be exercised in all
operations involving the use of stressing equipment as
wires/strands under high tensile stresses become a lethal
weapon.
9.11.5.3 During the jacking operation of any tensioning
element(s) the anchor shall be kept turned up close to
anchor plate, wherever possible, to avoid serious
damage, if a hydraulic line fails.
9.11.5.4 Pulling-headers, bolts and hydraulic jacks/
rams shall be inspected for signs of deformation and
failure. Threads on bolts and nuts should be frequently
inspected for diminishing cross section. Choked units
shall be carefully cleaned.
9.11.5.5 Care shall be taken that no one stands in line
with the tensioning elements and jacking equipment
during the tensioning operations and that no one is
directly over the jacking equipment when deflection is
being done. Signs and banders shall be provided to
prevent workers from working behind the jacks when
the stressing operation is in progress.
9.11.5.6 Necessary shields should be put up
immediately behind the prestressing jacks during
stressing operations.
9.11.5.7 Wedges and other temporary anchoring devices
shall be inspected before use.
9.11.5.8 The prestressing jacks shall be periodically
examined for wear and tear.
9.11.5.9 Prestressing shall be done in accordance with
Part 6 ‘Structural Design, Section 5 Plain, Reinforced
and Prestressed Concrete, Subsection 5B Prestressed
Concrete’ of the Code.
9.11.6 Erection of Prefabricated Members
9.11.6.1 A spreader beam shall be used wherever
possible so that the cable can be as perpendicular to
the members being lifted as practical. The angle
between the cable and the members to be lifted shall
not be less than 60°.
9.11.6.2 The lifting wires shall be tested for double the
load to be handled at least once in six months. The guy
line shall be of adequate strength to perform its function
of controlling the movement of members being lifted.
9.11.6.3 Temporary scaffolding of adequate strength
shall be used to support precast members at
predetermined supporting points while lifting and
placing them in position and connecting them to other
members.
9.11.6.4 After erection of the member, it shall be guyed
and braced to prevent it from being tipped or dislodged
by accidental impact when setting the next member.
9.11.6.5 Precast concrete units shall be handled at
specific picking points and with specific devices.
Girders and beams shall be braced during transportation
and handled in such a way as to keep the members
upright. Lifting, handling and installation of
prefabricated members shall be in accordance with
Part 6 ‘Structural Design, Section 7 Prefabrication and
Systems Building: Subsection 7A Prefabricated
Concrete’ of the Code.
9.11.6.6 Methods of assembly and erection specified
by the designer, shall be strictly adhered to at site.
Immediately on erecting any unit in position, temporary
connections or supports as specified shall be provided
before releasing the lifting equipment. The permanent
structural connections shall be established at the earliest
opportunity.
9.11.7 Heated Concrete
When heaters are being used to heat aggregates and
other materials and to maintain proper curing
temperatures, the heaters shall be frequently checked
for functioning and precautions shall be taken to avoid
hazards in using coal, liquid, gas or any other fuel.
9.11.8 Structural Connections
9.11.8.1 When reliance is placed on bond between
precast and in-situ concrete the contact surface of the
precast units shall be suitably prepared in accordance
with the specifications.
9.11.8.2 The packing of joints shall be carried out in
accordance with the assembly instructions.
9.11.8.3 Levelling devices, such as wedges and nuts
which have no load bearing function in the completed
structure shall be released or removed as necessary prior
to integrating the joints.
9.11.8.4 If it becomes necessary to use electric power
for in-situ work, the same should be stepped down to a
safe level as far as possible.
9.11.9 Workers working in any position where there is
a falling hazard shall wear safety belts or other adequate
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
45
protection shall be provided.
9.12 Additional Safety Requirements for Erection
of Structural Steel Work
9.12.1 Safety Organization
The agency responsible for erecting the steel work
should analyze the proposed erection scheme for safety;
the erection scheme should cover safety aspects right
from the planning stage up to the actual execution of
the work.
9.12.2 Safety of Workpersons
9.12.2.1 General
While engaging persons for the job the supervisor
should check up and make sure that they are skilled in
the particular job they have to perform.
The helmets shall be worn properly and at all times
during the work and shall conform to the accepted
standard [7(28)].
The safety goggles shall be used while performing
duties which are hazardous to eye like drilling, cutting
and welding. The goggles used shall conform to the
accepted standard [7(34)] and should suit individual
workers.
The welders and gas cutters shall be equipped with
proper protective equipment like gloves, safety boots,
aprons and hand shields [ see accepted standard 7(35)].
The filter glass of the hand shield shall conform to the
accepted standard [7(34)] and should be suitable to the
eyes of the particular worker.
When the work is in progress, the area shall be cordoned
off by barricades to prevent persons from hitting against
structural components, or falling into excavated
trenches or getting injured by falling objects.
Warning signs shall be displayed where necessary to
indicate hazards, for example (a) ‘440 V’, (b) ‘DO NOT
SMOKE’, (c) ‘MEN WORKING AHEAD’, etc. Hand
lamps shall be of low voltage preferably 24 V to prevent
electrical hazards.
All electrically operated hand tools shall be provided
with double earthing.
9.12.2.2 Anchors for guys or ties shall be checked for
proper placement. The weight of concrete in which the
anchors are embedded shall be checked for uplift and
sliding. Split-end eye anchors shall only be used in
good, solid rock. The first load lifted by a guy derrick
shall be kept at a small height for about 1 0 min and the
anchors immediately inspected for any signs or
indications of failure.
9.12.2.3 When a number of trusses or deep girders are
loaded in one car or on one truck, all but one being
lifted shall be tied back unless they have been tied or
braced to prevent their falling over and endangering
men unloading.
9.12.2.4 The erection gang shall have adequate supply
of bolts, washers, rivets, pins, etc, of the correct size.
Enough number of bolts shall be used in connecting
each piece using a minimum of two bolts in a pattern
to ensure that the joint will not fail due to dead load
and erection loads. All splice connections in columns,
crane girders, etc, shall be completely bolted or riveted
or welded as specified in the drawing before erection.
9.12.2.5 Girders and other heavy complicated structural
members may require special erection devices like
cleats and hooks, which can be shop assembled and
bolted or riveted or welded to the piece and may be
left permanently in the place after the work.
9.12.2.6 If a piece is laterally unstable when picked at
its centre, use of a balance beam is advisable, unless a
pair of bridles slings can be placed far enough apart,
for them to act as safe lifting points. The top flange of
a truss, girder or long beam may be temporarily
reinforced with a structural member laid flat on top of
the member and secured temporarily.
9.12.2.7 On deep girders, and even on some trusses, a
safety ‘bar’ running their full length will aid the riggers,
fitters and others employed on the bottom flange or
bottom chord to work with greater safety. This can be
a single 16 mm diameter wire rope through vertical
stiffeners of such members about 1 m above the bottom
flange and clamped at the ends with wire rope clamps.
If the holes cannot be provided, short eye bolts can be
welded to the webs of the girder at intervals to be
removed and the surface chipped or ground to leave it
smooth after all work on the piece has been completed.
9.12.2.8 Safety belts shall always be available at work
spot to be used, whenever necessary. The rope shall be
chemically treated to resist dew and rotting. These shall
not be tied on sharp edges of steel structures. They shall
be tied generally not more than 2 m to 3 m away from
the belt.
9.12.2.9 On a guy derrick or climbing crane job, the
tool boxes used by the erection staff shall be moved to
the new working floor each time the rig is changed. On
a mobile crane job, the boxes shall be moved as soon
as the crane starts operating in a new area not too far
away for the men to reach the boxes conveniently. While
working a tall and heavy guy derrick, it is advisable to
control tension in guys by hand winches to avoid jerks,
which may cause an accident.
9.12.2.10 The proper size, number and spacing of wire
rope clamps shall be used, depending on the diameter
of the wire rope. They shall be properly fixed in
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NATIONAL BUILDING CODE OF INDIA 2016
accordance with the procedure given in the accepted
standard [7(36)]. They shall be checked as soon as the
rope has been stretched, as the rope, especially if new,
tends to stretch under the applied load, which in turn
may cause it to shrink slightly in diameter. The clamps
shall then be promptly tightened to take care of this
new condition. In addition, the clamps shall be
inspected frequently to be sure that they have not
slipped and are tight enough.
9.12.2.11 When the men can work safely from the steel
structure itself, this is preferable to hanging platforms
or scaffolds, as it eliminates additional operations,
which in turn, reduces the hazard of an accident. To
aid men working on floats or scaffolds, as well as men
in erection gangs, or other gangs using small material,
such as bolts and drift pins, adequate bolt baskets or
similar containers with handles of sufficient strength
and attachment to carry the loaded containers, shall be
provided. The men should be trained to use such
containers, and to keep small tools gathered up and
put away in tool boxes when not in use. Material shall
not be dumped overboard when a scaffold is to be
moved. Rivet heaters shall have safe containers or
buckets for hot rivets left over at the end of the day.
9.12.2.12 During the erection of tall buildings, it is
desirable to use nylon nets of sufficient width at a height
of 3 m to 4 m from ground to provide safety to people.
The safety net should be made from man-made or
machine-made fibre ropes which are UV stabilized and
conforming to the accepted standard [7(37)].
9.12.2.13 Safety against fire
A fire protection procedure is to be set up if there is to
be any flame cutting, burning, heating, riveting or any
operation that could start a fire. For precautions to be
observed during welding and cutting operations,
reference may be made to good practice [7(38)]. The
workers should be instructed not to throw objects like
hot rivets, cigarette stubs, etc, around. Sufficient fire
extinguishers shall be placed at strategic points.
Extinguishers shall always be placed in cranes, hoists,
compressors and similar places. Where electrical
equipment are involved, C02 or dry powder extinguishers
shall be provided {see also good practice [7(24)]}.
9.12.2.14 Riding on a load, tackle or runner shall be
prohibited.
9.12.2.15 The load shall never be allowed to rest on
wire ropes. Ropes in operation should not be touched.
Wire rope with broken strand shall not be used for
erection work. Wire ropes/manila ropes conforming to
acceptable standards [7(39)] shall be used for guying.
9.12.2.16 Lifting appliances
Precautions as laid down in 9.11.1.2 shall be followed.
9.12.2.17 Slinging
Chains shall not be joined by bolting or wiring links
together. They shall not be shortened by tying knots. A
chain in which the links are locked, stretched or do not
move freely shall not be used. The chain shall be free
of kinks and twists. Proper eye splices shall be used to
attach the chain hooks.
Pulley blocks of the proper size shall be used to allow
the rope free play in the sheave grooves and to protect
the wire rope from sharp bends under load. Idle sling
should not be carried on the crane hook alongwith a
loaded sling. When idle slings are carried they shall be
hooked.
While using multilegged slings, each sling or leg shall
be loaded evenly and the slings shall be of sufficient
length to avoid a wide angle between the legs.
9.12.2.18 Riveting operations
9.12.2.18.1 Handling rivets
Care shall be taken while handling rivets so that they
do not fall, strike or cause injury to men and material
below. Rivet catchers shall have false wooden bottoms
to prevent rivets from rebounding.
9.12.2.18.2 Riveting dollies
Canvas, leather or rope slings shall be used for riveting
dollies. Chain shall not be used for the purpose.
9.12.2.18.3 Riveting hammers
Snaps and plungers of pneumatic riveting hammers
shall be secured to prevent the snap from dropping out
of place. The nozzle of the hammer shall be inspected
periodically and the wire attachment renewed when
bom.
9.12.2.18.4 Fire protection
The rivet heating equipment should be as near as
possible to the place of work. A pail of water shall
always be kept ready for quenching the fire during
riveting operations and to prevent fires when working
near inflammable materials.
9.12.2.19 Welding and gas cutting
9.12.2.19.1 For safety and health requirements in
electric gas welding and cutting operations, reference
may be made to good practice [7(40)]. The
recommendations given in 9.12.2.19.2 to 9.12.2.19.4
are also applicable.
9.12.2.19.2 All gas cylinders shall be used and stored
in the upright position only and shall be conveyed in
trolleys. While handling by cranes they shall be carried
in cages. The cylinders shall be marked ‘full’ or ‘empty’
as the case may be. Gas cylinders shall be stored away
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
47
from open flames and other sources of heat. Oxygen
cylinders shall not be stored near combustible gas, oil,
grease and similar combustible materials. When the
cylinders are in use, cylinder valve key or wrench shall
be placed in position. Before a cylinder is moved,
cylinder valve shall be closed. All cylinder valves shall
be closed when the torches are being replaced or
welding is stopped for some reason. The cylinder valve
and connections shall not be lubricated.
9.12.2.19.3 Gas cutting and welding torches shall be
lighted by means of special lighters and not with
matches. The cables from welding equipment should
be placed in such a way that they are not run over by
traffic. Double earthing shall be provided. Before
undertaking welding operations near combustible
materials, suitable blanketing shall be provided and fire
extinguishers kept nearby. Welding shall not be
undertaken in areas where inflammable liquids and
gases are stored.
9.12.2.19.4 Gas lines and compressed air lines shall
be identified by suitable colour codes for easy
identification, to avoid confusion and to prevent fire
and explosion hazards.
9.12.3 Safety of Structure
9.12.3.1 General
The structure itself should be safeguarded during its
erection. The first truss of the roof system shall be guyed
on each side before the hoisting rope is detached from
it. After the subsequent trusses and roof purlins are
erected, protective guides shall be firmly established
and the required wind bracings shall be erected to
prevent the whole structure being blown over by a
sudden gale at night. Bracing and guying precautions
shall be taken on every structure until it is complete.
Guying shall be specifically done for trusses and
structural components which after their erection form
an erection device. On structures used for temporary
material storage overloading shall be avoided.
9.12.3.1.1 Erection of columns shall be immediately
followed by vertical bracing between columns before
the roof structure is erected.
9.13 Miscellaneous Items
9.13.1 Staircase Construction
While staircase is under construction, depending on
the type of construction, namely, concrete or brickwork,
etc, suitable precautions shall be taken by way of
support, formworks, etc, to prevent any collapse.
Workers or any other person shall not be allowed to
use such staircases till they are tested and found fit for
usage by the Authority/engineer-in-charge. Till the
permanent handrails are provided, temporary provisions
like ropes, etc, shall be provided on staircases prior to
commencement of use of such staircases.
9.13.2 Lift Wells
Till the installation of the lift is completed, lift wells
shall be protected with check boards or railings together
with notice boards, danger lights, etc, to prevent persons
accidentally falling into the wells. The handrails
provided shall be capable of withstanding pressure
exerted due to nonnal bumping of an individual against
the same.
9.13.3 Construction Involving the Use of Hot
Bituminous Tar Materials
9.13.3.1 Safety programme
9.13.3.1.1 General
On all major works, an experienced and competent
foreman or supervisor shall be placed in-charge of the
work, and shall be made responsible for the strict
observance of the safety rules. He shall stock the
necessary protective equipment, fire extinguishing
equipment, first-aid kit, etc. He shall also keep a record
of the accidents taking place on any particular job, with
reasons thereof, and shall suggest suitable remedial
measures to the management for prevention thereof.
9.13.3.1.2 Protective covering
Workers engaged on jobs involving handling of hot
bitumen, tar, and bituminous mixtures shall use
protective wears, such as boots and gloves, preferably
of asbestos or otherwise of rubber; goggles and helmet.
No workers shall be permitted to handle such materials
without wearing the needed protective covering.
9.13.3.1.3 Fire fighting arrangements
When heating and handling of hot bituminous materials
is to be done in the open, sufficient stocks of clean dry
sand or loose earth shall be made available at the work
site to cope with any resultant fires. When neither such
materials are available, nor are any suitable type of fire
extinguishers provided at the work site in the open,
and reliance has to be on using water for fighting any
fire, the water supply available should be in abundance
and the water shall be applied to the fire in the form of
spray. When heating of bituminous materials is carried
out in enclosed spaces, sufficient number of properly
maintained dry powder fire extinguisher or foam
extinguisher conforming to accepted standards [7(23)]
shall be kept in readiness on the work site.
9.13.3.2 Sprayer, spreader/paver
9.13.3.2.1 Sprayer
The sprayer shall be provided with a fire resisting
screen. The screen shall have an observation window.
48
NATIONAL BUILDING CODE OF INDIA 2016
Piping for hot tar and bitumen shall be adequately
insulated to protect workers from injury by burns.
Flexible piping work under positive pressure shall be
of metal which shall be adequately insulated. Workers
shall not stand facing the wind directions while spraying
hot binder, lest it may fall on them causing bums.
9.13.3.2.2 Spreader/Paver
Spreaders in operation shall be protected by signals,
signs or other effective means. People should be warned
against walking over hot mixture laid. Gravel spreaders
shall always keep a safe distance from sprayer. Elevated
platforms on spreaders shall be protected by suitable
railing and be provided with an access ladder.
9.13.3.3 Equipment for heating of bitumen and tars
9.13.3.3.1 Tanks, vats, kettles, pots, drums and other
vessels for heating tar, bitumen and other bituminous
materials shall be,
a) adequately resistant to damage by heat,
transportation, etc;
b) capable of holding a full load without danger
of collapse, bursting or distortion;
c) provided with a close fitting cover suitable for
smothering a fire in the vessel or protection
from rain; and
d) leak proof, and provided with suitable outlets
which can be controlled for taking out the hot
material.
9.13.3.3.2 Suitable indicator gauges shall be used to
ascertain level and temperature of the material in the
boiler. On no account shall workers be allowed to peep
into the boiler for this purpose. For ascertaining levels,
in small plants, dipstick may also be used.
9.13.3.3.3 Gas and oil-fired bitumen and tar kettles or
pots shall be equipped with burners, regulators and
safety devices of types approved by the Authority.
Heating appliances for vessels shall distribute the heat
uniformly over the heating surface so as 'to avoid
overheating. In case of bituminous mixtures using
mineral aggregates filler together with bitumen, it is
preferable to have some means for stirring as well. Only
vessels heated by electricity shall be used inside
buildings. Tar boilers shall never be used on
combustible roof.
9.13.3.3.4 Buckets for hot bitumen, bituminous
materials of tar shall have,
a) the bail or handle firmly secured; and
b) a second handle near the bottom for tipping.
9.13.3.3.5 Bitumen or tar boilers mounted on wheels
for easy transport or towing shall preferably be provided
with hand pumps for spraying purposes.
9.13.3.3.6 Vessels in operation shall be kept at a safe
distance from combustible materials. When vessels are
used in confined spaces, the gases, fumes and smoke
generated shall be removed by exhaust ventilation or
by forced ventilations. Vessels that are being heated
shall not be left unattended. Pieces of bituminous
material shall not be thrown into the hot vessels so as
to cause splashing. Covers shall be kept closed when
vessels are not in use. Containers shall not be filled
with hot bitumen or tar to a level that might cause danger
when they are carried or hoisted. Enough space shall
be left in vessels for expansion of binder, when heated.
9.13.3.3.7 Bitumen/tar shall be kept dry and to avoid
fire due to foaming, boiler shall have a device that
prevents foam from reaching the burners or anti¬
foaming agents shall be used to control the same.
Alternatively, to avoid fire due to foaming, the heating
shall be at low temperature till the water entrapped, if
any, is completely evaporated. Any water present in
the boiler shall also be drained before using it for
heating binders. No open light shall be used for
ascertaining the level of binder in boilers. If a burner
goes out, the fuel supply shall be cut off and the heating
tube shall be thoroughly blown out by the fan so as to
prevent a back fire.
9.13.3.3.8 Cutbacks shall not be heated over an open
flame unless a water jacket is used. While they are being
heated the vessel shall be kept open.
9.13.3.3.9 Piping shall not be warmed with burning rags
and instead blow-lamps or similar devices shall be used.
9.13.3.3.10 Spilled bitumen or tar shall be promptly
cleaned up around boilers.
9.13.3.3.11 Inspection openings shall not be opened
while there is any pressure in the boiler.
9.13.3.3.12 When tanks are cleaned by steam, adequate
precautions shall be taken to prevent any build up of
pressure.
9.13.3.4 Handling bitumen/tar
Bitumen/tar shall not be heated beyond the temperature
recommended by the manufacturer of the product.
While discharging heated binder from the boiler,
workers shall not stand opposite to the jet so as to avoid
the possibility of hot binder falling on them. The
container shall be handled only after closing the control
valve. While handling hot bitumen/tar, workers shall
exercise scrupulous care to prevent accidental spillage
thereof. The buckets and cans in which the hot material
is carried from boiler shall be checked before use to
ensure that they are intact and safe. Mops and other
applicators contaminated with bituminous materials
shall not be stored inside buildings.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
49
9.13.3.5 Bitumen plants
Safety requirements shall be in accordance with good
practice [7(41)].
9.13.4 Timber Structure
Preventive measures against hazards in work places
involving construction of timber structures shall be
taken in accordance with good practice [7(42)].
9.14 Finishes
9.14.1 Painting, Polishing and Other Finishes
Only the quantity of paint, thinner and polish required
for the day’s work should be kept at the work spot.
9.14.1.1 All containers of paint, thinner and polish
which are not in actual use should be closed with tight
fitting lids and kept at a safe place away from the actual
work site.
9.14.1.2 A 5 kg dry powder fire extinguisher
conforming to the accepted standard [7(43)] shall be
kept handy.
9.14.1.3 Metal receptacles with pedal operated metal
lids shall be kept handy at the work site for depositing
used cotton rags/waste. The contents of such receptacles
shall be disposed off before the end of each day’s work
at a safe place, preferably by burning under proper
supervision.
9.14.1.4 All containers of paint shall be removed from
the work site and deposited in the paint store before
the close of day’s work. Used paint brushes shall be
cleaned and deposited in the store along with the
containers.
9.14.1.5 Some paints/polishing and finishing materials
are injurious to the health of workers. Adequate
protective clothing, respiratory equipment, etc, shall
be provided for the use of workers during such
operations where necessary.
9.15 Fragile Fixtures
It shall be ensured that sufficient number of workers
and equipment are provided to carry the fragile fixtures
like sanitary fittings, glass panes, etc, to prevent injury
to workers due to accidental dropping of such fixtures.
9.16 Safety in Special Operations
Safety in compressed air work, drilling, blasting and
welding operations shall be in accordance with good
practices [7(44)].
9.17 Electrical Installations and Lifts
9.17.1 Temporary Electrical Wiring
9.17.1.1 Frayed and/or bare wires shall not be used for
temporary electrical connections during constaiction.
50
All temporary wiring shall be installed and supervised
by a competent electrician. Adequate protection shall
be provided for all electrical wiring laid on floor which
may have to be crossed over by construction machinery
or by the workers. All flexible wiring connecting the
electrical appliances shall have adequate mechanical
strength and shall preferably be enclosed in a flexible
metal sheath. Overhead wires/cables shall be so laid
that they leave adequate head room.
9.17.1.2 All electrical circuits, other than those required
for illumination of the site at night, shall be switched
off at the close of day’s work. The main switch board
from which connections are taken for lighting, power
operated machinery, etc, shall be located in an easily
accessible and prominent place. No articles of clothing
nor stores shall be kept at the back of or over the board
or anywhere near it. One 3 kg/4.5 kg C02 extinguisher
or one 5 kg dry powder extinguisher conforming to the
accepted standard [7(43)] shall be provided near the
switch board.
9.7.1.3 Requirements as given in 12 ofPart 8 ‘Building
Services, Section 2 Electrical and Allied Installations’
of the Code shall also be complied with.
9.17.2 Permanent Electrical Installations
Besides the fire safety measures for electrical
installations covered under 9.17.1, safety in electric
installations in buildings and installations of lifts shall
be in accordance with 12 ofPart 8 ‘Building Services,
Section 2 Electrical and Allied Installations’ of the
Code, and Part 8 ‘Building Services, Section 5
Installation of Lifts, Escalators and Moving Walks’ of
the Code, respectively.
9.18 General Safety Requirements for Workplace
9.18.1 Sanitation
a) Adequate toilet facilities shall be provided for
the workers within easy access of their place
of work. The total number to be provided shall
be not less than one per 30 employees in any
one shift.
b) Toilet facilities shall be provided from the start
of building operations, and connection to a
sewer shall be made as soon as practicable.
c) Every toilet shall be so constructed that the
occupant is sheltered from view and protected
from the weather and falling objects.
d) Toilet facilities shall be maintained in a
sanitary condition. A sufficient quantity of
disinfectant shall be provided. Natural or
artificial illumination shall be provided.
NATIONAL BUILDING CODE OF INDIA 2016
e) An adequate supply of drinking water shall
be provided, and unless connected to a
municipal water supply, samples of the water
shall be tested at frequent intervals by the
Authority.
9.18.2 Fire Protection
9.18.2.1 In addition to the provision of fire extinguishers,
as specified in this part of the Code, other fire extinguishing
equipment shall also be provided and conveniently located
within the building under construction or on the building
site, as required by the Authority.
9.18.2.1.1 All fire extinguishers shall be maintained in
a serviceable condition at all times in accordance with
good practice [7(24)] and all necessary guidelines
regarding fire protection at workplaces followed in
accordance with good practice [7(21)].
9.18.2.1.2 It shall be ensured that all workers and
supervisory staff are fully conversant with the correct
operation and use of fire extinguishers provided at the
construction site.
9.18.2.1.3 Telephone number of local fire brigade
should be prominently displayed near each telephone
provided at construction site.
9.18.2.1.4 Watch and ward services should be provided
at construction sites during holidays and nights.
9.18.2.2 Access shall be provided and maintained at
all times to all fire fighting equipment, including fire
hose, extinguishers, sprinkler valves and hydrants.
9.18.2.2.1 Approach roads for fire fighting should be
planned, properly maintained and kept free from
blockage. Width of approach road should be not less
than 5 m to facilitate fire fighting operations.
9.18.2.2.2 Emergency plan and fire order specifying
the individual responsibility in the event of fire should
be formulated and mock drills should be practised
periodically in case of large and important construction
sites to ensure upkeep and efficiency of fire fighting
appliances.
9.18.2.2.3 Periodical inspection should be carried out
to identify any hazard and proper records maintained
and follow up action taken.
9.18.2.2.4 Evacuation facilities and fire exits should
be provided at all locations susceptible to fire hazards.
9.18.2.3 Where the building plans require the
installation of fixed fire fighting equipment, such as
hydrants, stand pipes, sprinklers and underground water
mains or other suitable arrangements for provision of
water shall be installed, completed and made available
for permanent use as soon as possible, but in any case
not later than the stage at which the hydrants, etc, are
required for use as specified in 9.18.2.3.1 to 9.18.2.3.4,
9.18.2.3.1 A stand pipe system (landing valves),
permanent in nature shall be installed and made
available before the building has reached the height of
15 m above the grade, and carried up with each floor.
9.18.2.3.2 The standpipe (landing valve/intemal fire
hydrant) and its installation shall conform to the
accepted standards [7(45)].
9.18.2.3.3 The standpipe shall be carried up with each
floor and securely capped at the top. Top hose outlets,
should at all times, be not more than one floor below
the floor under construction.
9.18.2.3.4 A substantial box, preferably of metal, should
be provided and maintained near each hose outlet. The
box should contain adequate lengths of hose to reach
all parts of the floor as well as a short branch fitted
with 12 mm or 20 mm nozzle.
9.18.2.4 Close liaison shall be maintained with the local
Fire Brigade, during construction of all buildings above
15 m in height and special occupancies, like
educational, assembly, institutional, industrial, storage,
hazardous and mixed occupancies with any of the
aforesaid occupancies having area more than 500 m2
on each floor.
9.18.2.5 It is desirable that telephone system or other
means of inter-communication system be provided
during the construction of all buildings over 15 m in
height or buildings having a plinth area in excess
of 1 000 m2.
9.18.2.6 All work waste, such as scrap timber, wood
shavings, sawdust, paper, packing materials and oily
waste shall be collected and disposed of safely at the
end of each day’s work. Particular care shall be taken
to remove all waste accumulation in or near vertical
shaft openings like stairways, lift-shaft, etc.
9.18.2.7 An independent water storage facility shall be
provided before the commencement of construction
operations for fire-fighting purposes. It shall be
maintained and be available for use at all times.
9.18.2.8 Fire cut-offs
Fire walls and exit stairways required for a building
should be given construction priority. Where fire doors,
with or without automatic closing devices, are stipulated
in the building plans they should be hung as soon as
practicable and before any significant quantity of
combustible material is introduced in the building.
9.18.2.8.1 As the work progresses, the provision of
permanent stairways, stairway enclosures, fire walls and
other features of the completed structure which will
prevent the horizontal and vertical spread of fire should
be ensured.
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9.18.3 Clothing
9.18.3.1 It shall be ensured that the clothes worn by
the workers be not of such nature as to increase the
chances of their getting involved in accident to
themselves or to others. As a rule, wearing of Chaddars
or loose garments shall be prohibited.
9.18.3.2 Workers engaged in processes which splash
liquid or other materials which will injure the skin shall
have enough protective clothing to cover the body.
9.18.3.3 Individuals engaged in work involving use of
naked flames (such as welding) shall not wear synthetic
fibre or similar clothing which increases the risk of fire
hazards.
9.18.4 Safety Measures Against Fall Prevention
Persons working at heights may use safety belts and
harnesses. Provision of cat-walks, wire mesh, railings
reduces chances of fall-ladder and scaffoldings,
stagings, etc, should be anchored on firm footing and
should be secured and railing should be provided as
far as possible. All accesses should be barricaded to
prevent accidental fall. For details as fall prevention
reference may be made to good practice [7(46)].
9.18.5 Falling Materials Hazard Prevention
Preventive measures against falling materials hazards
in work places shall be taken in accordance with good
practice [7(47)].
9.18.6 Disposal of Debris
Preventive measures against hazards relating to disposal
of debris shall be taken in accordance with [7(48)].
9.19 Construction Machinery
9.19.1 Specification and requirements of construction
machinery used in construction or demolition work shall
conform to accepted standards [7(49)].
9.19.2 For safety requirements for working with
construction machinery, reference may be made to good
practice [7(50)].
9.19.3 Petroleum powered air compressors, hoists,
derricks, pumps, etc, shall be so located that the
exhausts are well away from combustible materials.
Where the exhausts are pipes to outside the building
under construction, a clearance of at least 1 50 mm shall
be maintained between such piping and combustible
material.
9.19.4 Earthing/grounding of electrically powered
equipment/tools shall be ensured. Also all electric
powered equipment should be switched off from mains,
after completion of day’s job.
10 SAFETY IN DEMOLITION OF BUILDINGS
10.1 The safety requirements for carrying out
demolition/dismantling work shall be as given in 10.2
to 10.15.
10.2 Planning
Before beginning the actual work of demolition a
careful study shall be made of the structure which is to
be pulled down and also of all its surroundings. This
shall, in particular, include study of the manner in which
the various parts of the building to be demolished are
supported and how far the stage by stage demolition
will affect the safety of the adjoining structure. A
definite plan of procedure for the demolition work,
depending upon the manner in which the loads of the
various structural parts are supported, shall be prepared
and approved by the engineer-in-charge and this shall
be followed as closely as possible, in actual execution
of the demolition work. Before the commencement of
each stage of demolition, the foreman shall brief the
workers in detail regarding the safety aspects to be kept
in view.
It should be ensured that the demolition operations do
not, at any stage, and endanger the safety of the
adjoining buildings. Moreover, the nuisance effect of
the demolishing work on the use of the adjacent
buildings should be kept to the minimum.
No structure or part of the structure or any floor or
temporary support or scaffold, side wall or any device
for equipment shall be loaded in excess of the safe
carrying capacity, in its then existing condition.
Electrical installations for demolition sites shall be in
accordance with 12 of Part 8 ‘Building Services,
Section 2 Electrical and Allied Installations’ of the
Code.
10.3 Precautions Prior to Demolition
10.3.1 On every demolition job, danger signs shall be
conspicuously posted all around the structure and all
doors and openings giving access to the structure shall
be kept barricaded or manned except during the actual
passage of workers or equipment. However, provisions
shall be made for at least two independent exits for
escape of workers during any emergency.
10.3.2 During nights, red lights shall be placed on or
about all the barricades.
10.3.3 Where in any work of demolition it is imperative,
because of danger existing, to ensure that no
unauthorized person shall enter the site of demolition
during the outside hours; a watchman should be
employed. In addition to watching the site he shall also
be responsible for maintaining all notices, lights and
barricades.
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10.3.4 All the necessary safety appliances shall be
issued to the workers and their use explained. It shall
be ensured that the workers are using all the safety
appliances while at work.
10.3.5 The power on all electrical service lines shall
be shut off and all such lines cut or disconnected at or
outside the property line, before the demolition work
is started. Prior to cutting of such lines, the necessary
approval shall be obtained from the electrical
authorities concerned. The only exception will be any
power lines required for demolition work itself.
10.3.6 All gas, water steam and other service lines shall
be shut off and capped or otherwise controlled at or
outside the building line, before demolition work is
started.
10.3.7 All the mains and meters of the building shall
be removed or protected from damage.
10.3.8 If a structure to be demolished has been partially
wrecked by fire, explosion or other catastrophe, the
walls and damaged roofs shall be shored or braced
suitably.
10.3.9 Protection of the Public
10.3.9.1 Safety distances to ensure safety of the public
shall be clearly marked and prominently sign posted.
Every sidewalk or road adjacent to the work shall be
closed or protected. All main roads, which are open to
the public, shall be kept open to the public clear and
unobstructed at all times. Diversions for pedestrians
shall be constructed, where necessary for safety.
10.3.9.2 If the structure to be demolished is more than
two storeyed or 7.5 m high, measured from the side
walk or street which cannot be closed or safely diverted,
and the horizontal distance from the inside of the
sidewalk to the structure is 4.5 m or less, a substantial
sidewalk shed shall be constructed over the entire length
of the sidewalk adjacent to the structure, of sufficient
width with a view to accommodating the pedestrian
traffic without causing congestion. The side walk shed
shall be lighted sufficiently to ensure safety at all times.
For detailed information reference may be made to good
practice [7(51)].
A toe board of at least 1 m high above the roof of the
shed shall be provided on the outside edge and ends of
the sidewalk shed. Such boards may be vertical or
inclined outward at not more than 45°.
Except where the roof of a sidewalk shed solidly abuts
the structure, the face of the sidewalk shed towards the
building shall be completely closed by providing
sheeting/planking to prevent falling material from
penetrating into the shed.
The roof of sidewalk sheds shall be capable of
sustaining a load of 73 N/mm2. Only in exceptional
cases, say due to lack of other space, the storing of
material on a sidewalk shed may be permitted in which
case the shed shall be designed fora load of 146 N/mm2.
Roof of sidewalk shed shall be designed taking into
account the impact of the falling debris. By frequent
removal of loads it shall be ensured that the maximum
load, at any time, on the roof of work shed is not more
than 6 000 N/m2. The height of sidewalk shed shall be
such as to give a minimum clearance of 2.4 m.
Sidewalk shed opening, for loading purposes, shall be
kept closed at all time except during actual loading
operations.
The deck flooring of the sidewalk shed shall consist of
plank of not less than 50 mm in thickness closely laid
and deck made watertight. All members of the shed
shall be adequately braced and connected to resist
displacement of members or distortion of framework.
10.3.9.3 When the horizontal distance from the inside
of the sidewalk to the structure is more than 4.5 m and
less than 7.5 m, a sidewalk shed or fence or a substantial
railing shall be constructed on the inside of the sidewalk
or roadway along the entire length of the demolition
side of the property with movable bars as may be
necessary for the proper execution of the work.
NOTE — For guidance on management of pedestrians/cyclists/
vehicles near road construction sites, reference may be made
to IRC SP 55 : 2014 ‘Guidelines on traffic management in work
zones’.
10.4 Precautions During Demolition
10.4.1 Prior to commencement of work, all material of
fragile nature like glass shall be removed.
10.T2 Ml openings shall be boarded up.
10.4.3 Dust shall be controlled by suitable means to
prevent harm to workers.
10.4.4 Stacking of materials or debris shall be within
safe limits of the structural member. Additional
supports, where necessary, shall be given.
10.4.5 Adequate natural or artificial lighting and
ventilation shall be provided for the workers.
10.5 Sequence of Demolition Operations
10.5.1 The demolition work shall be proceeded with in
such a way that,
a) it causes the least damage and nuisance to the
adjoining building and the members of the
public; and
b) it satisfies all safety requirements to avoid any
accidents.
10.5.2 All existing fixtures required during demolition
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53
operations shall be well protected with substantial
covering to the entire satisfaction of the rules and
regulations of the undertakings or they shall be
temporarily relocated.
10.5.3 Before demolition work is started, glazed sash,
glazed doors and windows, etc, shall be removed. All
fragile and loose fixtures shall be removed. The lath
and all loose plaster shall be stripped off throughout
the entire building. This is advantageous because it
reduces glass breakage and also eliminates a large
amount of dust producing material before more
substantial parts of the buildings are removed.
10.5.4 All well openings which extend down to floor
level shall be barricaded to a height of not less than
one metre above the floor level. This provision shall
not apply to the ground level floor.
10.5.5 All floor openings and shafts not used for
material chutes shall be floored over and be enclosed
with guard rails and toe boards.
10.5.6 The demolition shall always proceed
systematically storey by storey in descending order. All
work in the upper floor shall be completed and
approved by the engineer-in-charge prior to disturbance
to any supporting member on the lower floor.
Demolition of the structure in sections may be permitted
in exceptional cases, if proper precautions are ensured
to prevent injuries to persons and damage to property.
10.6 Walls
10.6.1 While walls of sections of masonry are being
demolished, it shall be ensured that they are not allowed
to fall as single mass upon the floors of the building
that are being demolished so as to exceed the safe
carrying capacity of the floors. Overloading of floors
shall be prevented by removing the accumulating debris
through chutes or by other means immediately. The
floor shall be inspected by the engineer-in-charge before
undertaking demolition work and if the same is found
to be incapable to carry the load of the debris, necessary
additional precautions shall be taken so as to prevent
any possible unexpected collapse of the floor.
10.6.2 Walls shall be removed part by part. Stages shall
be provided for the men to work on if the walls are less
than one and a half brick thick and dangerous to work
by standing over them.
10.6.3 Adequate lateral bracing shall be provided for
walls which are unsound. For detailed information
reference may be made to good practice [7(51)].
10.7 Flooring
10.7.1 Prior to removal of masonry or concrete floor
adequate support centering shall be provided.
10.7.2 When floors are being removed, no worker or
person shall be allowed to work in the area, directly
underneath and such area shall be barricaded to prevent
access to it.
10.7.3 Planks of sufficient strength shall be provided
to give workers firm support to guard against any
unexpected floor collapse.
10.8 Demolition of Steel Structures
10.8.1 When a derrick is used, care shall be taken to
see that the floor on which it is supported is amply
strong for the loading so imposed. If necessary heavy
planking shall be used to distribute the load to floor
beam and girders.
10.8.2 Overloading of equipment shall not be allowed.
10.8.3 Tag lines shall be used on all materials being
lowered or hoisted up and a standard signal system shall
be used and the workers instructed on the signals.
10.8.4 No person shall be permitted to ride the load
line.
10.8.5 No beams shall be cut until precautions have
been taken to prevent it from swinging freely and
possibly striking any worker or equipment or to any
part of the structure being demolished.
10.8.6 All structural steel members shall be lowered
from the building and shall not be allowed to drop.
10.9 Catch Platform
10.9.1 In demolition of exterior walls of multistorey
structures, catch platform of sufficient strength to
prevent injuries to workers below and public shall be
provided, when the external walls are more than 20 m
in height.
10.9.2 Such catch platform shall be constructed and
maintained not more than 3 storeys below the storey
from which exterior wall is being demolished. When
demolition has progressed to within 3 storeys of ground
level, catch platform will not be considered necessary.
10.9.3 Catch platform shall be capable of sustaining a
live load of not less than 6 100 N/m2.
10.9.4 Materials shall not be dumped on the catch
platform nor shall they be used for storage of materials.
10.10 Stairs, Passageways and Ladders
10.10.1 Stairs with railings, passageways and ladders
shall be left in place as long as possible and maintained
in a safe condition.
10.10.2 All ladders shall be secured against, slipping
out at the bottom and against movement in any direction
at the top.
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10.11 Mechanical Demolition
When demolition is to be performed by mechanical
devices, such as weight ball and power shovels, the
following additional precautions may be observed:
a) The area shall be barricaded for a mipimum
distance of 1 Vi times the height of the wall;
b) While the mechanical device is in operation,
no worker shall be allowed to enter the
building being demolished;
c) The device shall be so located as to avoid
falling debris; and
d) The mechanical device, when being used, shall
not cause any damage to adjacent structure,
power line, etc.
10.12 Demolition of Certain Special Types and
Elements of Structures
10.12.1 Roof Trusses
If a building has a pitched roof, the structure should be
removed to wall plate level by hand methods. Sufficient
purlins and bracing should be retained to ensure stability
of the remaining roof trusses while each individual truss
is removed progressively.
10.12.1.1 Temporary bracing should be added, where
necessary, to maintain stability. The end frame opposite
to the end where dismantling is commenced, or a
convenient intermediate frame should be independently
and securely guyed in both directions before work
starts.
10.12.1.2 On no account should the bottom tie of roof
trusses be cut until the principal rafters are prevented
from making outward movement.
10.12.1.3 Adequate hoisting gears suitable for the loads
shall be provided. If during demolition any thing is to
be put on the floor below the level of the truss, it shall
be ensured that the floor is capable of taking the load.
10.12.2 Heavy Floor Beams
Heavy baulks of timber and steel beams should be
supported before cutting at the extremities and should
then be lowered gently to a safe working place.
10.12.3 Jack Arches
Where tie rods are present between main supporting
beams, these should not be cut until after the arch or
series of arches in the floor have been removed. The
floor should be demolished in strips parallel to the span
of the arch rings (at right angles to the main floor
beams).
10.12.4 Brick Arches
Expert advice should be obtained and, at all stages of
the demolition, the closest supervision should be given
by persons fully experienced and conversant in the type
of work to ensure that the structure is stable at all times.
However, the following points may be kept in view:
a) On no account should the restraining influence
of the abutments be removed before the dead
load of the spandrel fill and the arch rings are
removed.
b) A single span arch can be demolished by hand
by cutting narrow segments progressively
from each springing parallel to the span of the
arch, until the width of the arch has been
reduced to a minimum which can then be
collapsed.
c) Where deliberate collapse is feasible, the
crown may be broken by the demolition ball
method working progressively from edges to
the centre.
d) Collapse of the structure can be affected in
one action by the use of explosives. Charges
should be inserted into bore holes drilled in
both arch and abutments.
e) In multi-span arches, before individual arches
are removed, lateral restraint should be
provided at the springing level. Demolition
may then proceed as for single span; where
explosives are used it is preferable to ensure
the collapse of the whole structure in one
operation to obviate the chance of leaving
unstable portion standing.
10.12.5 Cantilever (Not Part of a Framed Structure)
Canopies, cornices, staircases and balconies should be
demolished or supported before tailing down load is
removed.
10.12.6 In-situ Reinforced Concrete
Before commencing demolition, the nature and
condition of the concrete, the condition and position
of reinforcement, and the possibility of lack of
continuity of reinforcement should be ascertained.
Demolition should be commenced by removing
partitions and external non-load bearing cladding.
10.12.6.1 Reinforced concrete beams
A supporting rope should be attached to the beam. Then
the concrete should be removed from both ends by
pneumatic drill and the reinforcement exposed. The
reinforcement should then be cut in such a way as to
allow the beam to be lowered under control to the floor.
10.12.6.2 Reinforced concrete columns
The reinforcement should be exposed at the base after
restraining wire guy ropes have been placed round the
member at the top. The reinforcement should then be
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
55
cut in such a way as to allow it to be pulled down to the
floor under control.
10.12.6.3 Reinforced concrete walls
These should be cut into strips and demolished as for
columns.
10.12.6.4 Suspended floors and roofs
The slab should be cut into strips parallel to the main
reinforcement and demolished strip by strip. Where
ribbed construction has been used, the principle of
design and method of construction should be
determined before demolition is commenced. Care
should be taken not to cut the ribs inadvertently.
10.12.7 Precast Reinforced Concrete
Due precautions shall be taken to avoid toppling over
of prefabricated units or any other part of the structure
and whenever necessary temporary supports shall be
provided.
10.12.8 Prestressed Reinforced Concrete
Before commencing of the demolition work, advice of
an engineering expert in such demolition shall be
obtained and followed.
10.13 Lowering, Removal and Disposal of Materials
10.13.1 Dismantled materials may be thrown to the
ground only after taking adequate precautions. The
material shall preferably be dumped inside the building.
Normally such materials shall be lowered to the ground
or to the top of the sidewalk shed where provided by
means of ropes or suitable tackles.
10.13.2 Through Chutes
10.13.2.1 Wooden or metal chutes may be provided
for removal of materials. The chutes shall preferably
be provided at the centre of the building for efficient
disposal of debris.
10.13.2.2 Chutes, if provided at an angle of more than
45° from the horizontal, shall be entirely enclosed on
all the four sides, except for opening at or about the
floor level for receiving the materials.
10.13.2.3 To prevent the descending material attaining
a dangerous speed, chute shall not extend in an
unbroken line for more than two storeys. A gate or stop
shall be provided with suitable means for closing at
the bottom of each chute to stop the flow of materials.
10.13.2.4 Any opening into which workers dump debris
at the top of chute shall be guarded by a substantial
guard rail extending at least one metre above the level
of the floor or other surface on which men stand to
dump the materials into the chute.
10.13.2.5 A toe board or bumper, not less than 50 mm
thick and 1 50 mm high shall be provided at each chute
openings, if the material is dumped from the wheel
barrows. Any space between the chute and the edge of
the opening in the floor through which it passes shall
be solidly planked over.
10.13.3 Through Holes in the Floors
10.13.3.1 Debris may also be dropped through holes
in the floor without the use of chutes. In such a case the
total area of the hole cut in any intermediate floor, one
which lies between floor that is being demolished and
the storage floor shall not exceed 25 percent of such
floor area. It shall be ensured that the storage floor is
of adequate strength to withstand the impact of the
falling material.
10.13.3.2 All intermediate floor openings for passage
of materials shall be completely enclosed with
barricades or guard rails not less than one metre high
and at a distance of not less than 1 m from the edge of
general opening. No barricades or guard rails shall be
removed until the storey immediately above has been
demolished down to the floor line and all debris cleared
from the floor.
10.13.3.3 When the cutting of a hole in an intermediate
floor between the storage floor and the floor which is
being demolished makes the intermediate floor or any
portion of it unsafe, then such intermediate floor shall
be properly shored. It shall also be ensured that the
supporting walls are not kept without adequate lateral
restraints.
10.13.4 Removal of Materials
10.13.4.1 As demolition work proceeds, the released
serviceable materials of different types shall be
separated from the unserviceable lot (hereinafter called
‘Malta’) at suitable time intervals and properly stocked
clear of the spots where demolition work is being done.
10.13.4.2 The Malta obtained during demolition shall
be collected in well-formed heaps at properly selected
places, keeping in view safe conditions for workers in
the area. The height of each Malta heap shall be limited
to ensure its toppling over or otherwise endangering
the safety of workers or passersby.
10.13.4.3 The Malta shall be removed from the
demolition site to a location as required by the local
civil authority. Depending on the space available at the
demolition site, this operation of conveying Malta to
its final disposal location may have to be carried out a
number of times during the demolition work. In any
case, the demolition work shall not be considered as
completed and the area declared fit for further
occupation till all the Malta has been carried to its
final disposal location and the demolition areas tidied
up.
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10.13.4.4 Materials which are likely to cause dust
nuisance or undue environmental pollution in any other
way, shall be removed from the site at the earliest and
till then they shall be suitably covered. Such materials
shall be covered during transportation also.
10.13.4.5 Following other requirements should also be
met:
a) Glass and steel should be dumped or buried
separately to prevent injury.
b) Workman should be provided with suitable
protective gears for personal safety during
works, like safety helmets, boots, hand gloves,
goggles, special attire, etc.
c) Work of removal of debris should be carried
out during day. In case of poor visibility
artificial light may be provided.
d) Debris should first be removed from top. Early
removal from bottom or sides of dump may
cause collapse of debris, causing injuries.
10.14 Miscellaneous
10.14.1 No demolition work should be carried out
during night as far as possible, especially when the
structure to be demolished is in an inhabited area. If
such night work has to be done, additional precautions
by way of additional red warning signals, working lights
and watchmen, shall be provided to avoid any injury
to workers and public. Demolition work shall not be
carried out during storm and heavy rain.
10.14.2 Warning devices shall be installed in the area
to warn the workers in case of any danger.
10.14.3 Safety devices like industrial safety helmets
conforming to the accepted standards [7(28)] and
goggles made of celluloid lens, shall be issued to the
workers. Foreman-in-charge of the work areas shall
ensure that all the workers are wearing the safety
devices before commencing any work.
10.14.4 Construction sheds and tool boxes shall be so
located as to protect workers from injuries from the
falling debris.
10.14.5 Where there is a likelihood of injuries to hands
of workers when demolishing RCC, steel structures, etc,
gloves of suitable materials shall be worn by workers.
10.14.6 Sufficient protection by way of both overhead
cover and screens shall be provided to prevent injuries
to the workers and the public.
10.14.7 Safety belts or ropes shall be used by workers
when working at higher levels.
10.14.8 Grading of Plot
When a building has been demolished and no building
operation has been projected or approved, the vacant
plot shall be filled, graded and maintained in conformity
to the established street grades at kerb level. The plot
shall be maintained free from the accumulation of
rubbish and all other unsafe and hazardous conditions
which endangers the life or health of the public; and
provisions shall be made to prevent the accumulation
of water or damage to any foundations on the premises
or the adjoining property.
10.15 First-Aid
10.15.1 A copy of all pertinent regulations and notices
concerning accidents, injury and first-aid shall be
prominently exhibited at the work site.
10.15.2 Depending on the scope and nature of the work,
a person, qualified in first-aid shall be available at work
site to render and direct first-aid to casualties. He shall
maintain a list of individuals qualified to serve in first-
aid work. Enough first-aid kit, including a stretcher and
a cot with accessories shall be provided at site. A
telephone may be provided to first-aid assistant with
telephone numbers of the hospitals prominently
displayed.
Complete reports of all accidents and action taken
thereon shall be forwarded to the competent authorities.
SECTION 5 REPAIRS, RETROFITTING AND
STRENGTHENING OF BUILDINGS
11 MAINTENANCE MANAGEMENT
Maintenance management of building is the art of
preserving over a long period what has been
constructed. Whereas construction stage lasts for a short
period, maintenance continues for comparatively very
large period during the useful life of building.
Inadequate or improper maintenance adversely affects
the environment in which people work, thus affecting
the overall output. In the post construction stage the
day to day maintenance or upkeep of the building shall
certainly delay the decay of the building structure.
Though the building may be designed to be very durable
it needs maintenance to keep it in good condition. The
maintenance management of buildings shall be done
in accordance with Part 12 ‘Asset and Facility
Management’ of the Code.
12 PREVENTION OF CRACKS
12.1 Cracks in buildings are of common occurrence. A
building component develops cracks whenever stress
in the component exceeds its strength. Stress in a
building component could be caused by externally
applied forces, such as dead, imposed, wind or seismic
loads, or foundation settlement or it could be induced
internally due to thermal movements, moisture changes,
chemical action, etc.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
57
12.2 Cracks could be broadly classified as structural
or non-structural. Structural cracks are those which are
due to incorrect design, faulty construction or
overloading and these may endanger the safety of a
building. Extensive cracking of an RCC beam is an
instance of structural cracking. Non-structural cracks
are mostly due to internally induced stresses in building
materials and these generally do not directly result in
structural weakening. In course of time, however,
sometime non-structural cracks may, because of
penetration of moisture through cracks or weathering
action, result in corrosion of reinforcement and thus
may render the structure unsafe. Vertical cracks in a
long compound wall due to shrinkage or thermal
movement is an instance of non-structural cracking.
Non-structural cracks, normally do not endanger the
safety of a building, but may look unsightly, or may
create an impression of faulty work or may give a
feeling of instability. In some situations, cracks may,
because of penetration of moisture through them, spoil
the internal finish, thus adding to cost of maintenance.
It is, therefore, necessary to adopt measures of
prevention or minimization of these cracks.
12.3 For complete details on causes and prevention of
non-structural cracks, reference shall be made to good
practice SP 25:1984 ‘Handbook on causes and
prevention of cracks in buildings’.
13 REPAIRS AND SEISMIC STRENGTHENING
OF BUILDINGS
13.1 General Principles and Concepts
13.1.1 Non-structural/ Architectural Repairs
13.1.1.1 The buildings affected by earthquake may
suffer both non-structural and structural damages. Non-
structural repairs may cover the damages to civil and
electrical items, including the services in the building.
Repairs to non-structural components need to be taken
up after the structural repairs and retrofitting work are
carried out. Care should be taken about the connection
details of architectural components to the main
structural components to ensure their stability.
13.1.1.2 Non-structural and architectural components
get easily affected/ dislocated during the earthquake.
These repairs involve one or more of the following:
a) Patching up of defects such as cracks and fall
of plaster;
b) Repairing doors, windows, replacement of
glass panes;
c) Checking and repairing electric conduits/
wiring;
d) Checking and repairing gas pipes, water pipes
and plumbing services;
e) Rebuilding non-structural walls, smoke
chimneys, parapet wulls, etc;
f) Replastering of walls, as required;
g) Rearranging disturbed roofing tiles;
h) Relaying cracked flooring at ground level; and
j) Redecoration - white washing, painting, etc.
The architectural repairs as stated above do not restore
the original structural strength of structural components
in the building and any attempt to carry out only repairs
to architectural/non-structural elements, neglecting the
required structural repairs, may have serious
implications on the safety of the building. The damage
would be more severe in the event of the building being
shaken by a similar shock because original energy
absorption capacity of the building would have been
reduced.
13.1.2 Structural Repairs/Restoration
13.1.2.1 Prior to taking up of the structural repairs for
restoration of original strength and any strengthening
measures, it is necessary to conduct detailed damage
assessment to determine,
a) the structural condition of the building to
decide whether a structure is amenable for
repair; whether continued occupation is
permitted; to decide the structure as a whole
or a part require demolition, if considered
dangerous;
b) if the structure is considered amenable for
repair then detailed damage assessment of the
individual structural components (mapping of
the crack pattern, distress location; crushed
concrete, reinforcement bending/yielding,
etc). Non-destructive testing techniques could
be employed to determine the residual strength
of the members; and
c) to work out the details of temporary supporting
arrangement of the distressed members so that
they do not undergo further distress due to
gravity loads.
13.1.2.2 After the assessment of the damage of
individual structural elements, appropriate repair
methods are to be carried out component-wise
depending on the extent of damage. The restoration
work may consist of the following:
a) Removal of portions of cracked masonry walls
and piers and rebuilding them in richer mortar.
Use of non-shrinking mortar will be
preferable.
b) Addition of reinforcing mesh on both faces
of the cracked wall, holding it to the wall
through spikes or bolts and then covering it,
suitably, with cement mortar or micro¬
concrete (maximum size of aggregate limited
58
NATIONAL BUILDING CODE OF INDIA 2016
to 6 mm or less as suitable), and may be with
use of micro-reinforcement as fibre or ferro-
cement.
c) Injecting cement, polymer-cement mixture or
epoxy materials, which are strong in tension,
into the cracks in walls.
d) The cracked reinforced concrete elements
may be repaired by epoxy grouting and could
be strengthened by epoxy or polymer mortar
application like shotcreting, jacketing, etc.
NOTE — In mortar for masonry or plaster, fibres can be used.
13.1.3 Seismic Strengthening
The main purpose of the seismic strengthening is to
upgrade the seismic resistance of a damaged building
while repairing so that it becomes safer under future
earthquake occurrences. This work may involve some
of the following actions:
a) Increasing the lateral strength in one or both
directions by increasing column and wall
areas or the number of walls and columns.
b) Giving unity to the structure, by providing a
proper connection between its resisting
elements, in such a way that inertia forces
generated by the vibration of the building can
be transmitted to the members that have the
ability to resist them. Typical important
aspects are the connections between roofs or
floors and walls, between intersecting walls
and between walls and foundations.
c) Eliminating features that are sources of
weakness or that produce concentration of
stresses in some members. Asymmetrical
plan distribution of resisting members, abrupt
changes of stiffness from one floor to the
other, concentration of large masses and large
openings in walls without a proper peripheral
reinforcement are examples of defects of this
kind.
d) Avoiding the possibility of brittle modes of
failure by proper reinforcement and
connection of resisting members.
13.1.4 Seismic Retrofitting
Many existing buildings do not meet the seismic
strength requirements of present earthquake codes due
to original structural inadequacies and material
degradation due to time or alterations carried out
during use over the years. Their earthquake resistance
can be upgraded to the level of the present day codes
by appropriate seismic retrofitting techniques, such
as mentioned in 13.1.3.
13.1.5 Strengthening or Retrofititng Versus
Reconstruction
13.1.5.1 Replacement of damaged buildings or
existing unsafe buildings by reconstruction is,
generally, avoided due to a number of reasons, the
main ones among them being,
a) higher cost than that of strengthening or
retrofitting;
b) preservation of historical architecture; and
c) maintaining functional social and cultural
environment.
In most instances, however, the relative cost of
retrofitting to reconstruction cost determines the
decision. As a thumb rule, if the cost of repair and
seismic strengthening is less than about 50 percent of
the reconstruction cost, the retrofitting is adopted. This
may also require less working time and much less
dislocation in the living style of the population. On
the other hand reconstruction may offer the possibility
of modernization of the habitat and may be preferred
by well-to-do communities.
13.1.5.2 Cost wise the building construction including
the seismic code provisions in the first instance, works
out to be the cheaper in terms of its own safety and
that of the occupants. Retrofitting an existing
inadequate building may involve as much as 4 to 5
times the initial extra expenditure required on seismic
resisting features. Repair and seismic strengthening
of a damaged building may even be 5 to 10 times as
expensive. It is, therefore, very much safe as well as
cost-effective to construct earthquake resistant
buildings at the initial stage itself according to the
relevant seismic IS codes.
13.2 For detailed guidelines for repairs and seismic
strengthening of masonry buildings, reference shall
be made to good practice [7(52)].
13.3 For detailed guidelines for improving earthquake
resistance of low strength masonry buildings,
reference shall be made to good practice [7(53)].
13.4 For detailed guidelines for improving earthquake
resistance of earthen buildings, reference shall be
made to good practice [7(54)].
13.5 For detailed guidelines for seismic evaluation
and strengthening of existing reinforced concrete
buildings, reference shall be made to good practice
[7(55)]..
SECTION 6 HABITAT AND WELFARE
REQUIREMENTS FOR WORKERS
14 HABITAT AND OTHER WELFARE
REQUIREMENTS FOR CONSTRUCTION
WORKERS
14.1 The following aspects relating to habitat and other
welfare requirements for construction workers at site
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
59
shall be met with, in accordance with 14.2 to 14.16:
a) Habitat site selection criteria;
b) Area requirements for the various facilities of
the habitat;
c) Design of the habitat including the
construction materials;
d) Specifications of living area, height of the
rooms, windows and doors, ventilation;
e) Specification and requirements for kitchen and
other sanitary facilities, such as toilets,
bathrooms, etc;
f) Fire and safety requirements;
g) First aid and medical requirements;
h) Creches;
j) Habitat operation and maintenance;
k) Security;
m) Recreational facilities;
n) Waste management;
p) Habitat inspection and monitoring; and
q) Other facilities.
The project authorities should, depending on size of
the project, number of workers employed, location of
the project, etc, provide these facilities for the workers.
They should also decide the nature of facilities that
should be provided at the workplace within working
hours.
14.2 Habitat Site Selection Criteria
14.2.1 The criteria given in 14.2.1.1 to 14.2.1.5 shall
be met while selecting habitat site for construction
workers.
14.2.1.1 Workers habitat shall be located away from
overhead electrical lines. If due to non-availability of
space, the habitat need to be located in the proximity
of electrical line, minimum clearances as given in Part 3
‘Development Control Rules and General Building
Requirements’ of the Code shall be provided.
14.2.1.2 Workers’ habitat shall be located sufficiently
away from areas like sewage channels, effluent
treatment plants, garbage dumping yards, etc.
14.2.1.3 The site selected shall be such that it does not
get flooded during monsoon and drainage system
available around the site for run-off water.
14.2.1.4 The site shall be separated from the
construction site/public area by physical barrier such
as fences.
14.2.1.5 Appropriate provisions shall be made for
access to the site; and depending upon the location
thereof, transportation of workers from their habitat to
work locations.
14.3 Minimum Area Requirements
The area requirements as given in Table 1 shall be
adopted in a construction workers’ habitat.
For female workers and if workers’ accommodation is
provided for families of workers, separate sanitation
facility for women with adequate privacy shall be
provided as per Table 1 .
Table 1 Area Requirements in Construction
Workers’ Habitat
( Clause 14.3)
SI
No.
Description
Quantity
(1)
(2)
(3)
i)
Minimum floor area per
3.6 nf
ii)
person
Maximum number of
10
iii)
persons per room
Minimum height of the
2.7 m, if two tier beds
iv)
room
Minimum area of kitchen
are provided 3 m
0.60 m2
v)
vi)
vii)
per person
Number of lavatories, Min
Number of bathrooms, Min
Number of urinals, Min
1 per 10 person
1 unit per 15 person
1 per 25 person
14.4 Minimum Facilities to be Provided in Rooms
Following minimum facilities shall be provided in
rooms of construction workers:
a) Adequate natural light during the day time and
adequate artificial light;
b) Adequate ventilation to ensure sufficient
movement of air in all conditions of weather
and climate;
c) Lockable doors and windows, provided with
mosquito screens where conditions warrant;
d) A separate bed for each worker;
e) Adequate furniture for each worker to secure
his or her personal belongings, such as, a
ventilated clothes locker which can be locked
by the occupant to ensure privacy;
f) Separate storage for work boots and other
personal protection equipment to be provided
depending on conditions;
g) As far as practicable, sleeping rooms be so
arranged that shifts are separated and that no
workers working during the day share a room
with workers on night shifts;
h) Beds not to be arranged in tiers of more than
two.
14.5 Design and Construction of the Habitat
Design and construction of the workers’ habitat meeting
60
NATIONAL BUILDING CODE OF INDIA 2016
the requirements given in 14.2 to 14.4 shall be
structurally sound and may be constructed at site or
erected as prefabricated single/two storied
accommodation.
14.6 Sanitary Facilities
Following sanitary facilities shall be provided at habitat
for construction workers at site:
a) Every lavatory shall be under cover and so
partitioned off as to secure privacy, and shall
have a proper door and fastenings.
b) Where both male and female building workers
are employed, separate sanitary facilities shall
be provided for female workers. There shall
be displayed outside each block of lavatories
or urinals a notice containing therein ‘For Men
Only’ or ‘For Women Only’, as the case may
be, written in the language understood by the
majority of such workers. Such notice shall
also bear the figure of a man or of a woman,
as the case may be.
c) Every lavatory or urinal shall be conveniently
situated and accessible to building workers at
all times.
d) Every lavatory or urinal and washing facilities
shall be adequately lighted and shall be
maintained in a clean and sanitary condition
at all times.
e) Every lavatory or urinal other than those
connected with a flush sewage system shall
comply with the requirements of the public
health authorities.
f) Water seal lavatories may be provided on the
basis of community toilets or shared toilets as
per the recommendation given in good
practice [7(56)].
g) Water shall be provided by means of a tap or
otherwise so as to be conveniently accessible
in or near every lavatory or urinal.
h) The walls, ceilings and partitions of every
lavatory or urinal shall be white-washed or
colour-washed once in every period of six
months.
j) Waste water from wash areas, bathrooms and
toilets shall be drained in septic tanks/soak
pits and suitably disposed in municipal
sewerage systems. For very large habitat,
sewage treatment plant may be installed. No
waste water shall be discharged to ground or
other sources without proper treatment.
k) Septic tanks/soak pits shall be located at a
minimum distance of 18 m from the wells.
Location of septic tank shall meet the
requirements of good practice [7(57)].
14.7 Drinking Water Requirements
14.7.1 Sufficient quantity of potable water shall be
made available for drinking. Drinking water shall meet
the requirements of the accepted standard [7(58)] and
water quality shall be monitored regularly.
14.7.2 Drinking water outlet shall be so located such
that the distance to travel to nearest outlet shall not be
more than 30 m. Drinking water tanks should be legibly
marked ‘Drinking Water’ in a language understood by
a majority of the workers and shall be located at
least 6 m away from washing place, urinal or lavatory.
14.7.3 Sampling and testing of drinking water for
checking its conformity to meet the requirements
of 14.7.1 should be carried out quarterly through
accredited laboratory.
14.7.4 Storage tanks shall be cleaned as part of regular
maintenance procedure to prevent growth of slime and
collection of sediments.
14.8 First Aid and Medical Facilities
14.8.1 First aid centre shall be established in the habitat
with the required medical facilities. Trained first aiders/
male nurse/doctor shall be employed in the First Aid
Centre depending on the number of workers
accommodated. Sufficient number of first-aid boxes
shall be provided and maintained and the box shall be
distinctly marked ‘First-aid’ and shall be equipped with
specified articles.
14.8.2 An emergency vehicle shall be provided or an
arrangement shall be made with an identified nearby
hospital for providing ambulance for transportation of
serious cases of accident or sickness of workers to the
hospital promptly. Such vehicle should be maintained
in good repair and should be equipped with standard
facilities. The contact details, including phone numbers
of such nearby hospitals shall be readily available to
different managers/supervisors/first-aid facility in¬
charge. These phone numbers shall also be suitably
displayed at site.
14.8.3 Details of all the first-aid/medical treatments
shall be logged in the first aid register.
14.8.4 Lighting of 300 lux shall be maintained in the
first aid centre.
14.8.5 Health check-up of all the workers shall be done
at least once in six months by a registered medical
practitioner.
14.8.6 The medical facilities shall meet the provisions
of Building and other Construction Workers
(Regulation of Employment and Conditions of Service)
Act, 1996 and rules framed thereunder.
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
61
14.9 Cooking Area
Cooking shall not be permitted in the living area.
Separate designated kitchen shall be provided meeting
the minimum area requirements given in 14.3. Canteen
and cooking facilities should provide sufficient space
for preparing food and eating, as well as conform to
hygiene and safety requirements. When workers can
individually cook their meals, they should be provided
with a space separate from the sleeping areas. Facilities
must be kept in a clean and sanitary condition.
14.10 Creches
In every place wherein more than fifty female building
workers are ordinarily employed, there shall be
provided and maintained, a suitable room or rooms for
the use of children under the age of six years of such
female workers. Such rooms shall,
a) provide adequate accommodation;
b) be adequately lighted and ventilated;
c) be maintained in a clean and sanitary
condition; and
d) be under the charge of women trained in the
care of children and infants.
14.11 Habitat Operation and Maintenance
14.11.1 A detailed plan shall be prepared for the
operation and maintenance of the habitat facilities. The
plan shall cover all aspects of the operation, preventive
and routine maintenance.
14.11.2 Qualified and experienced in-house electrical/
maintenance personnel shall be present and available.
A supervisor shall be appointed to supervise hygiene
in the habitat facilities. Sufficient cleaners shall be
employed to ensure that the buildings and sanitary
facilities are always clean and hygienic.
14.11.3 Regular pest and insect control measures shall
be taken up to avoid mosquito/pest breeding. This may
be done through an approved agency.
14.11.4 Worker’s transportation may be done with
standard passenger vehicle/bus, where required.
14.12 Fire Prevention
14.12.1 Fire extinguishers shall be provided such that
one should not have to travel more than 1 5 m distance
to access a fire extinguisher.
14.12.2 Diesel generator shed and inflammable liquid
storage areas shall be provided with foam type fire
extinguishers and fire buckets.
14.12.3 Electrical fittings in the inflammable storage
areas shall be flame proof.
14.12.4 ‘No Smoking’ boards shall be displayed in gas
cylinder and flammable liquid storage areas.
14.12.5 All the security and habitat maintenance
personnel, habitat residents and site workers shall be
trained on use of fire extinguishers.
14.13 Recreation
Internal and external recreational facilities may be made
available depending on the number of workers to be
accommodated. Reasonable access to telephone or
other modes of communications, with any charges for
the use of these services being reasonable in amount,
shall be provided.
14.14 Security
14.14.1 Adequate number of security personnel shall
be deployed. Specific security personnel shall be
deployed at the main entry gate for restricting
unauthorized entry and checking vehicle/material exit
and entry.
14.14.2 Security staff shall receive adequate training
on first aid, firefighting and emergency preparedness.
Security staff shall have a good understanding about
the importance of respecting workers’ rights and the
rights of the communities. Security staff shall have the
emergency lights, torches and other accessories
required to facilitate during emergency situations.
14.14.3 A minimum of 50 lux lighting shall be
maintained in the roads, parking area, boundary wall
and other general areas of the habitat.
14.15 Other Facilities
Other facilities like provisional stores with separate
counters for vegetables, etc, may also be provided in a
construction workers habitat.
Facilities like induction/initiation room may be planned
as the part of habitat for awareness, education and other
related work site requirements.
14.16 Habitat Inspection
Periodical inspection of the habitat shall be carried out
by an identified team preferably once in a month. The
team shall record their findings on the Inspection Report
form and team shall also review and follow-up
implementation of the suggested measures. The above
periodic inspection report of the habitat should be
submitted to Project-in-Charge.
14.17 Notwithstanding the requirements given in 14.1
to 14.16, all provisions given in relevant Act/Rules/
Regulations as amended from time to time shall be
followed; in this regard, reference shall also be made
to the Building and other Construction Workers
(Regulation of Employment and Conditions of Service)
Act, 1 996 and the rules/regulations framed thereunder.
62
NATIONAL BUILDING CODE OF INDIA 2016
ANNEX A
{Clause 8.2.1)
CHECK LIST FOR STACKING AND STORAGE OF MATERIALS
SI No. Material/ Component Base Stack Type °f Cover
Firm Hard
Off- Heaps
Tiers Flat Vertical Open Open but
Under
Level pioor
Ground
Floor
Covered
Shed
(1)
(2)
(3)
(4) (5)
(6)
(7)
(8)
(9)
(10)
(ID
(12)
1.
Cement
y
V
V
2.
Lime:
a) Quick lime
y
V
V
b) Hydrated lime
y
V
y
3.
Stones and aggregates:
a) Stones, aggregates, fly
V
V
y
ash and cinder
b) Veneering stones
V
V
V
y
4.
Bricks and blocks
y
V
y
5.
Tiles:
a) Clay and concrete
y
V
V
y
floor, wall and roof
tiles
b) Ceramic tiles
y
V
V
y
6.
Partially pre-fabricated
wall and roof components:
a) RC planks.
y
y
y
prefabricated brick
panels and ferro-
cement panels
b) Channel units, cored
y
V
y
units and L-Panels
c) Waffle units, RC
y
y
y
joists, single tee and
double tee
7.
Timber
y
y
y
8.
Steel
y
y
y
9.
Aluminium sections
y
y
y
10.
Doors, windows and
ventilators
y
y
y
11.
Roofing sheets:
a) AC
y
y
y
y
b) GI and aluminium
y
y
y
y
sheets
c) Plastic sheets
y
y
y
y
12.
Boards like plywood,
particle boards, fibre
y
y
y
y
boards, blockboards and
gypsum board
PART 7 CON STURCTION MANAGEMENT, PRACTICES AND SAFETY
63
ANNEX A — ( Concluded )
(1)
(2)
(3)
(4)
(5)
(6) (7)
(8)
(9)
(10)
(11)
(12)
13.
Plastic and rubber flooring:
a) Sheets in rolls
Y
v'
Y
b) Tiles
✓
Y
✓
Y
14.
Glass sheets
v'
v'
Y
15.
Glass bricks/blocks
✓
Y
Y
16.
Cl, GI and AC pipes and
fittings:
a) Pipes
Y
Y
>/
Y
b) Cl and GI fittings
Y
Y
c) AC fittings
Y
Y
17.
Polyethylene pipes
v'
Y
Y
18.
Unplasticized PVC pipes
Y
Y
v'
Y
19.
Bitumen, road tar, asphalt,
etc, in drums
Y
Y
Y
20.
Oil paints
Y
Y
Y
21.
Sanitary appliances
Y
v'
Y
LIST OF STANDARDS
The following list records those standards which are
acceptable as ‘good practice’ and ‘accepted standards’
in the fulfillment of the requirements of the Code. The
latest version of a standard shall be adopted at the time
of enforcement of the Code. The standards listed may
be used by the Authority for conformance with the
requirements of the referred clauses in the Code.
In the following list, the number appearing in the first
column within parantheses indicates the number of the
reference in this Part.
IS No.
Title
(1) 7337:2010
10400 : 2013
15198 : 2014
(2) 16416:2016
(3) 14580
Glossary of terms in project
management ( second
revision )
Glossary of terms in
inventory management
{second revision )
Glossary of terms in human
resource development
Construction project
management: Project
formulation and
appraisal — Guidelines
Use of network analysis for
project management
IS No.
(Part 1) : 1998
(Part 2) : 2006
(4) 15883 (Part 6) :
2015
(5) 15883 (Part 7)
(6) 15883 (Part 2) :
2013
(7) 15883 (Part 3):
2015
(8) 15883 (Part 4) :
2015
(9) 15883 (Part 8) :
2015
(10) 15883 (Part 9)
Title
Management, planning,
review, reporting and
termination procedures
Use of graphic techniques
Guidelines for construction
project management: Part 6
Scope management
Guidelines for construction
project management: Part 7
Procurement management
{under preparation)
Guidelines for construction
project management: Part 2
Time management
Guidelines for construction
project management: Part 3
Cost management
Guidelines for construction
project management: Part 4
Quality management
Guidelines for construction
project management: Part 8
Risk management
Guidelines for construction
64
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
IS No.
Title
Title
(11) 15883 (Part 10)
(12) 15883 (Part 5) :
2013
(13) 15883 (Part 11)
(14) 15883 (Part 12) :
2016
(15) a) Foundations
1080 : 1985
1904 : 1986
2911
(Part 1/Sec 1) :
2010
(Part 1/Sec 2) :
2010
(Part 1/Sec 3) :
2010
(Part 1/Sec 4) :
2010
(Part 2) : 1980
(Part 3) : 1980
(Part 4) : 2013
2974
project management: Part 8
Communication manage¬
ment ( under preparation)
Guidelines for construction
project management: Part 10
Human resource manage¬
ment ( under preparation )
Guidelines for construction
project management: Part 5
Health and safety manage¬
ment
Guidelines for construction
project management: Part 11
Sustainability management
(i under preparation )
Guidelines for construction
project management: Part 12
Integration management
Code of practice for design
and construction of shallow
foundations on soils (other
than raft, ring and shell)
( second revision )
Code of practice for design
and construction of
foundations in soils:
General requirements {third
revision)
Code of practice for design
and construction of pile
foundations
Concrete piles. Section 1
Driven cast in-situ concrete
piles {second revision)
Concrete piles, Section 2
Board cast in-situ concrete
piles {second revision)
Concrete piles. Section 3
Precast driven concrete
piles {second revision)
Concrete piles, Section 4
Precast concrete piles in
prebored holes ( first
revision)
Timber piles {first revision)
Under-reamed piles (first
revision)
Load test on piles {second
revision)
Code of practice for design
(Part 1) : 1982
(Part 2) : 1980
(Part 3) : 1992
(Part 4) : 1 979
(Part 5) : 1 987
9456 : 1980
9556 : 1980
12070 : 1987
13094 : 1992
14593 : 1998
15284
(Part 1) : 2003
(Part 2) : 2004
b) Masonry
IS No.
1597
(Part 1) : 1992
and construction of
machine foundations
Foundations for reci¬
procating type machines
(second revision)
Foundations for impact
type machines (hammer
foundations) (first revision)
Foundations for rotary type
machines (medium and
high frequency) (second
revision)
Foundations for rotary type
machines of low frequency
(first revision)
Foundations for impact
machines other than
hammers forging and
stamping press pig breakers
(drop crusher and jolter)
(first revision)
Code of practice for design
and construction of conical
and hyperbolic paraboidal
types of shell foundations
Code of practice for design
and construction of
diaphragm walls
Code of practice for design
and construction of shallow
foundations on rock
Guidelines for selection of
ground improvement
techniques for foundation
in weak soils
Design and construction of
bored cast-in-situ piles
founded on rocks —
Guidelines
Design and construction for
ground improvement:
Stone columns
Preconsolidation using
vertical drains
Title
Code of practice for
construction of stone
masonry
Rubble stone masonry ( first
revision)
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
65
IS No.
(Part 2) : 1992
2110 : 1980
2212 : 1991
2250 : 1981
2572 : 2005
3630 : 1992
4407 : 1967
4441 : 1980
4442 : 1980
4443 : 1980
6041 : 1985
6042 : 1969
c) Timber and Bamboo
IS No.
1634 : 1992
2366 : 1983
Title
Ashlar masonry (first
revision)
Code of practice for in-situ
construction of walls in
buildings with soil-cement
(first revision)
Code of practice for
brickwork (first revision)
Code of practice for
preparation and use of
masonry mortars (first
revision)
Code of practice for
construction of hollow and
solid concrete block
masonry (first revision)
Code of practice for
construction of non-load
bearing gypsum block
partitions (first revision)
Code of practice for reed
walling
Code of practice for use of
silicate type chemical
resistant mortars (first
revision)
Code of practice for use of
sulphur type chemical
resistant mortars (first
revision)
Code of practice for use of
resin type chemical
resistant mortars (first
revision)
Code of practice for
construction of autoclaved
cellular concrete block
masonry (first revision)
Code of practice for
construction of light weight
concrete block masonry
(first revision)
Title
Code of practice for design
and constructions of wood
stair for houses (second
revision)
Code of practice for nail-
jointed timber construction
(first revision)
IS No.
3670 : 1989
4913 : 1968
4983 : 1968
5390 : 1984
11096 : 1984
12506 : 1988
d) Concrete
IS No.
456 : 2000
457 : 1957
1343 : 2012
2502 : 1963
2541 : 1991
3370
(Part 1) : 2009
(Part 2) : 2009
(Part 3) : 1967
3558 : 1983
Title
Code of practice for
construction of timber
floors (first revision)
Code of practice for
selection, installation and
maintenance of timber
doors and windows
Code of practice for design
and construction of nail
laminated timber beams
Code of practice for
construction of timber
ceilings (first revision)
Code of practice for design
and construction of bolt-
jointed timber construction
Code of practice for
improved thatching of roof
with wrought and fire
retardant treatment
Title
Code of practice for plain
and reinforced concrete
(fourth revision)
Code of practice for general
construction of plain and
reinforced concrete for
dams and other massive
structures
Code of practice for pre¬
stressed concrete ( second
revision)
Code of practice for
bending and fixing of bars
for concrete reinforcement*
Code of practice for
preparation and use of lime
concrete ( second revision)
Code of practice for
concrete structures for the
storage of liquids:
General requirements (first
revision)
Reinforced concrete
structures (first revision)
Prestressed concrete
structures
Code of practice for use of
immersion vibrators for
consolidating concrete
(first revision)
66
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
Title
IS No.
4926 : 2003
Code of practice for ready-
mixed concrete (second
revision)
(Part 1) : 1989
5817 : 1992
Code of practice for
preparation and use of lime
pozzolana mixture concrete
(Part 2) : 1989
in buildings and roads (first
8629 (Parts 1 to 3)
revision)
1977
7246 : 1974
Recommendations for use
of table vibrators for
consolidating concrete
9077 : 1979
7861
Code of practice for extreme
whether concreting:
(Part 1) : 1975
Recommended practice for
hot weather concreting
9172 : 1979
(Part 2) : 1981
Recommended practice for
cold weather concreting
10262 : 2009
Guidelines for concrete mix
design proportioning (first
f) Flooring and Roofing
revision)
658 : 1982
10359 : 1982
Code of practice for
manufacture and use of
lime pozzolana concrete
blocks for paving
1196 : 1978
14687 : 1999
Guidelines for falsework
for concrete structures
e) Steel
1197 : 1970
IS No.
Title
800 : 2007
Code of practice for general
1198 : 1982
construction in steel (third
revision)
801 : 1975
Code of practice for use of
cold formed light gauge
steel structural members in
general building construc¬
tion (first revision)
1443 : 1972
805 : 1968
Code of practice for use of
2118 : 1980
steel in gravity water tanks
806 : 1968
Code of practice for use of
steel tubes in general
building construction (first
revision)
2119 : 1980
4000 : 1992
Code of practice for high
strength bolts in steel
structures (first revision)
4180 : 1967
Code of practice for
corrosion protection of
2204 : 1962
light gauge steel sections
used in building
2571 :. 1970
6533
Code of practice for design
and construction of steel
Title
chimneys:
Mechanical aspects (first
revision )
Structural aspects (first
revision)
: Code of practice for
protection of iron and
steel structures from
atmospheric corrosion
Code of practice of
corrosion protection of
steel reinforcement in RB
and RCC construction
Recommended design
practice for corrosion
prevention of steel
structures
Code of practice for
magnesium oxychloride
composition floors ( second
revision)
Code of practice for laying
bitumen mastic flooring
(second revision)
Code of practice for laying
of rubber floors (first
revision)
Code of practice for laying,
fixing and maintenance of
linoleum floor (first
revision)
Code of practice for laying
and finishing of cement
concrete flooring tiles (first
revision)
Code of practice for
construction of jack-arch
type of building floor or
roof (first revision)
Code of practice for
construction of brick-cum-
concrete composite
(Madras terrace) floor or
roof (first revision)
Code of practice for
construction of reinforced
concrete shell roof
Code of practice for laying
in-situ cement concrete
flooring (first revision)
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
67
IS No.
Title
IS No.
Title
2700 : 1987
Code of practice for roofing
revision)
with wooden shingles (first
revision)
9472 : 1980
Code of practice for laying
mosaic parquet flooring
2792 : 1964
Code of practice for design
and construction of stone
slab over joist floor
10297 : 1982
Code of practice for design
and construction of floors
and roofs using precast
2858 : 1984
Code of practice for roofing
with Mangalore tiles (first
revision )
reinforced/prestressed
concrete ribbed or cored
slab units
3007
Code of practice for laying
of asbestos cement sheets
10440 : 1983
Code of practice for
construction of reinforced
(Part 1) : 1999
Corrugated sheets (first
revision)
brick and RBC floors and
roofs
(Part 2) : 1999
Semi-corrugated sheets
first revision)
10505 : 1983
Code of practice for
construction of floors and
3670 : 1989
Code of practice for
construction of timber
floors first revision)
g) Finishes
roofs using precast concrete
waffle units
5119
Code of practice for laying
IS No.
Title
and fixing of sloped roof
coverings
1346 : 1991
Code of practice for
waterproofing of roofs with
(Part 1) : 1968
Slating
bitumen felts ( third
5318 : 1969
Code of practice for laying
revision)
of flexible PVC sheet and
tile flooring
1414 : 1989
Code of practice for fixing
wall coverings
5389 : 1969
Code of practice for laying
of hard wood parquet and
wood block floors
1477
Code of practice for
painting of ferrous metals in
buildings
5390 : 1984
Code of practice for
(Part 1) : 1971
Pretreatment first revision)
construction of timber
(Part 2) : 1971
Painting first revision)
ceilings first revision)
1609 : 1991
Code of practice for laying
5766 : 1970
Code of practice for laying
burnt clay brick flooring
damp-proofing treatment
using bitumen felts (second
6061
Code of practice for
revision)
construction of floor and
roof with joists and filler
blocks
1661 : 1972
Code of practice for
application of cement and
cement lime plaster finishes
(Part 1) : 1971
With hollow concrete filler
first revision)
blocks
2114 : 1984
Code of practice for laying
(Part 2) : 1981
With hollow clay filler
blocks first revision)
in-situ terrazzo floor finish
first revision)
(Part 3) : 1981
Precast hollow clay blocks
joists and hollow clay filler
blocks
2115 : 1980
Code of practice for flat-
roof finish : Mud Phuska
(second revision)
(Part 4) : 1981
6332 : 1984
With precast hollow clay
block slab panels
Code of practice for
2338
Code of practice for
finishing of wood and wood
based materials
construction of floors and
roofs using precast doubly-
(Part 1) : 1967
Operations and work¬
manship
curved shell units (first
(Part 2) : 1967
Schedules
68
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
Title
2394 : 1984
Code of practice for
application of lime plaster
finish {first revision)
2395
Code of practice for
painting concrete, masonry
and plaster surfaces
(Part 1) : 1994
Operations and work¬
manship (first revision)
(Part 2) : 1994
Schedule (first revision)
2402 : 1963
Code of practice for
external rendered finishes
2441 : 1984
Code of practice for fixing
ceiling covering (first
revision)
2524
Code of practice for
painting of non-ferrous
metals in buildings
(Part 1) : 1968
Pre-treatment
(Part 2) : 1968
Painting
3036 : 1992
Code of practice for laying
lime concrete for a water¬
proofed roof finish (second
revision)
3067 : 1988
Code of practice for general
design details and
preparatory work for damp¬
proofing and waterproofing
of buildings (first revision)
3140 : 1965
Code of practice for
painting asbestos cement
building products
4101
Code of practice for
external facing and veneers
(Part 1) : 1967
Stone facing
(Part 2) : 1967
Cement concrete facing
(Part 3) : 1985
Wall tiling and mosaics
(first revision)
4365 : 1967
Code of practice for
application of bitumen
mastic for waterproofing of
roofs
4597 : 1968
Code of practice for
finishing of wood and wood
based products with
nitrocellulose and cold
catalysed materials
4631 : 1986
Code of practice for laying
of epoxy resin floor
toppings (first revision)
5491 : 1969
Code of practice for laying
IS No. Title
in-situ granolithic concrete
floor topping
6278 : 1971
Code of practice for white¬
washing and colour
washing
6494 : 1988
Code of practice for
waterproofing of
underground water
reservoirs and swimming
pools (first revision)
7198 : 1974
Code of practice for damp¬
proofing using bitumen
mastic
7290 : 1979
Recommendations for use
of polyethylene film for
waterproofing of roofs (first
revision)
9918 : 1981
Code of practice for in-situ
waterproofing and damp¬
proofing treatments with
glass fibre tissue reinforced
bitumen
10439 : 1983
Code of practice for patent
glazing
16135 : 2014
Code of practice for dry
lining and partitioning
using gypsum plasterboards
16231
Code of practice of use of
glass in buildings
(Part 1) : 2016
General methodology and
selection
(Part 2) : 2016
Energy and light
(Part 3) : 2016
Fire and loading
(Part 4) : 2014
Piping
Safety related to human
impact
IS No.
Title
783 : 1985
Code of piactice for laying
of concrete pipes (first
revision)
3114 : 1994
Code of practice for laying
of cast iron pipes (second
revision)
4127 : 1983
Code of practice for laying
of glazed stoneware pipes
(first revision)
5329 : 1983
Code of practice for
sanitary pipe work above
ground for buildings (first
revision)
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
69
IS No.
Title
5822 : 1994
Code of practice for laying
of welded steel pipes for
water supply ( second
revision )
6530 : 1972
Code of practice for laying
of asbestos cement pressure
pipes
7634
Code of practice for
plastics pipe work for
portable water supplies
(Part 1) : 1975
Choice of materials and
general recommen-dations
(Part 2) : 2012
Laying and jointing
polyethylene (PE) pipes
(first revision )
(Part 3) : 2003
Laying and jointing of
unplasticized PVC pipes
13916 : 1994
zasurements
Code of practice for
installation of glass fibre
reinforced plastic piping
system
IS No.
Title
1200
Method of measurement of
building and civil
engineering works
(Part 1) : 1992
Earthwork fourth revision )
(Part 2) : 1974
Concrete work ( third
revision )
(Part 3) : 1976
Brickwork ( third revision )
(Part 4)1976
Stone masonry ( third
revision)
(Part 5) : 2013
Formwork fourth revision )
(Part 6) : 1974
Refactory work ( second
revision )
(Part 7): 2013
Hardware ( third revision )
(Part 8) : 1993
Steel work and iron work
fourth revision)
(Part 9) : 1973
Roof covering (including
cladding) ( second revision)
(Part 10) : 2013
Ceiling and linings ( third
revision)
(Part 11) : 2013
Paving, floor finishes dado
and skirting (fourth
revision)
(Part 12) : 1976
Plastering and pointing
(third revision)
(Part 13) : 1994
White washing, colour
washing, distempering and
painting of building
surfaces fifth revision)
IS No.
Title
(Part 14) : 1984
Glazing (third revision)
(Part 15) : 1987 .
Paining, polishing,
varnishing, etc fourth
revision)
(Part 16) : 1979
Laying of water and sewer
lines including appurtenant
items (third revision)
(Part 17) : 1985
Roadwork including air
field pavements (third
revision)
(Part 18) : 1974
Demolition and dis¬
mantling (third revision)
(Part 19) : 1981
Water supply, plumbing and
drains (third revision)
(Part 20) : 1981
Laying of gas and oil pipe
lines (third revision)
(Part 21) : 1973
Woodwork and joinery
(second revision)
(Part 23) : 1988
Piling fourth revision)
(Part 24) : 1983
Well foundations ( third
revision)
(Part 27) : 2013
Earth work done by
mechanical appliances
3861 : 2002
Method of measurement of
plinth, carpet and rentable
areas of buildings (second
revision)
Others
IS No.
Title
1081 : 1960
Code of practice for fixing
and glazing of metal (steel
and aluminium) doors,
windows and ventilators
1649 : 1962
Code of practice for design
and construction of flues
and chimneys for domestic
heating appliances
1946 : 1961
Code of practice for use of
fixing devices in walls,
ceilings and floors of solid
construction
2470
Code of practice for
installation of septic tanks
(Part 1) : 1985
Design criteria and
construction (second
revision)
(Part 2) : 1985
Secondary treatment and
disposal of septic tank
effluent (second revision)
2527 : 1984
Code of practice for fixing
rain-water gutters and down
70
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
Title
pipes for roof drainage
{first revision)
3414 : 1968
Code of practice for design
and installation of joints in
buildings
3548 : 1988
Code of practice for glazing
in buildings (first revision )
3558 : 1983
Code of practice for use of
immersion vibrators for
consolidating concrete
(first revision)
3935 : 1966
Code of practice for
composite construction
4326 : 2013
Code of practice for
earthquake resistant design
and construction of
buildings ( third revision)
4913 : 1968
Code of practice for
selection, installation and
maintenance of timber
doors and windows
6313
Code of practice for anti¬
termite measures in
buildings
(Part 1) : 1981
Constructional measures
(first revision)
(Part 2) : 2013
Pre-constructional
chemical treatment
measures (third revision)
(Part 3) : 2013
Treatment for existing
buildings (third revision)
6924 : 1973
Code of practice for the
construction of refuse
chutes in multistoreyed
buildings
7246 : 1974
Recommendation for use of
table vibrators for
consolidating concrete
8147 : 1976
Code of practice for use of
aluminium alloys in
structures
15345 : 2003
Code of practice for
installation of frameless
door and window shutters
15916 : 2010
Code of practice for buil¬
ding design and erection
using prefabricated
concrete
15917 : 2010
Code of practice for
building design and
erection using mixed/
composite construction
IS No.
Title
(16) 2750 : 1964
Specification for steel
scaffoldings
14687 : 1999
Guidelines for falsework
for concrete structures
3696 (Part 1) :
1987 Safety code for scaffolds
and ladders: Part 1
Scaffolds
4014
Code of practice for steel
tubular scaffolding
(Part 1) : 1967
Definitions and materials
(Part 2) : 2013
Safety regulations for
scaffolding (first revision)
(17) 6521 (Part 1)
1 972 Code of practice for design
of tower cranes: Part 1
Static and rail mounted
(18) 13558 (Part 3)
: Cranes — control — layout
1995
and characteristics: Part 3
Tower cranes
(19) 14687 : 1999
Guidelines for falsework
for concrete structures
(20) 3764 : 1992
Safety code for excavation
work (first revision)
(21) 13416 (Part 5) :
Recommendations for
1994
preventive measure against
hazards at workplaces :
Part 5 Fire protection
(22) 11769 (Part 1) :
Guidelines for safe use of
1987
products containing
asbestos : Part 1 Asbestos
cement products
(23) 15683 : 2006
Specification for portable
fire extinguishers —
Performance and
construction
16018 : 2012
Specification for wheeled
fire extinguishers —
Performance and
•
construction
(24) 2190 : 2010
Code of practice for
selection, installation and
maintenance of first-aid fire
extinguishers (fourth
revision)
(25) 8758 : 2013
Code of practice for fire
precautionary measures in
construction of temporary
structures and pandals
( second revision)
(26) 10439 : 1983
Code of practice patent
glazing
14687 : 1999
Guidelines for falsework
for concrete structures
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
71
IS No.
Title
(27) 4138 : 1977
Safety code for working in
compressed air (first
revision )
(28) 2925 : 1984
Specification for industrial
safety helmets ( second
revision)
(29) 2750 : 1964
Specification for steel
scaffoldings
(30) 3696 (Part 1) :
1987 Safety code for scaffolds
and ladders: Part 1
Scaffolds
4014 (Part 2) :
2013 Code of practice for steel
tubular scaffolding: Part 2
Safety provisions for
scaffolding (first revision)
(31) 3696 (Part 2) :
1991 Safety code for scaffolds
and ladders: Part 2 Ladders
(32) 4912 : 1978
Safety requirements for
floors and wall openings,
railing and toe boards (first
revision)
(33) 11461 : 1985
Code of practice for
compressor safety
(34) 5983 : 1980
Specification for eye-
protectors (first revision)
(35) 1179 : 1967
Specification for equipment
for eye and face protection
during welding (first
revision)
(36) 2361 : 2002
Specification for bull-dog
grips (third revision)
(37) 11057 : 1984
Specification for industrial
safety nets
(38) 3016 : 1982
Code of practice for fire
precautions in welding and
cutting operations (first
revision)
(39) 1084 : 2005
Specification for manila
ropes (fifth revision)
2266 : 2002
Specification for steel wire
ropes for general
engineering purposes (forth
revision)
(40) 818 : 1968
Code of practice for safety
and health requirements in
electric and gas welding
and cutting operations (first
revision)
(41) 5916 : 2013
Constructions involving
use of hot bituminous
materials — Code of safety
IS No.
Title
(42) 13416 (Part 4) :
Recommendations for
1994
preventive measure against
hazards at workplaces : Part
4 Timber structure
(43) 15683 : 2006
Portable fire extinguishers
— Performance and
construction — Speci¬
fication
(44) 819 : 1957
Code of practice for
resistance spot welding for
light assemblies in mild
steel
1261 : 1959
Code of practice for seam
welding in mild steel
3016 : 1982
Code of practice for fire
precautions in welding and
cutting operations (first
revision)
4081 : 2013
Blasting and related drilling
operations — Code of
Safety (second revision)
4138 : 1977
Safety code for working in
compressed gas (first
revision)
9595 : 1996
Recommendations for
metal arc welding of carbon
and carbon manganese
steels (first revision)
10178 : 1995
Recommended procedure
for C02 gas shielded metal-
arc welding of structural
steels (first revision)
(45) 3844 : 1989
Code of practice for
installation and
maintenance of internal fire
hydrants and hose reels on
premises (first revision)
5290 : 1993
Specification for landing
valves (third revision)
(46) 13416 (Part 2) :
Recommendation for
1992
preventive measures
against hazards at work
places: Part 2 Fall
prevention
(47) 13416 (Part 1) :
Recommendation for
1992
preventive measures
against hazards at work
places: Part 1 Falling
material hazard prevention
(48) 13416 (Part 3) :
Recommendation for
1994
preventive measures
against hazards at work
72
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
Title
IS No.
Title
places: Part 3 Disposal of
(Part 3) : 1999
Emulsion (third revision)
debris
2431 : 1963
Specification for steel
(49) 274
Specification for shovels
wheel barrows (single
(Part 1) : 1981
General purpose shovels
wheel-type)
(third revision )
2438 : 1963
Specification for roller pan
(Part 2) : 1981
Heat-treated shovels ( third
mixer
revision)
2505 : 1992
Specification for concrete
663 : 1980
Specification for adzes
(second revision)
vibrators, immersion type
(General requirements)
704 : 1984
Specification for crow bars
(third revision)
and claw bars (second
revision)
2506 : 1985
General requirements for
screed board concrete
841 : 1983
Specification for steel
vibrators (first revision)
hammers (second revision)
2514 : 1963
Specification for concrete
844
Specification for screw
vibrating tables
drivers
2587 : 1975
Specification for pipes
(Part 2) : 1979
Dimensions (second
revision)
vices (open side type and
fixed sides type) (first
(Part 3) : 1979
Dimensions for screw
revision)
drivers for recessed head
screws (second revision)
2588 : 1975
Specification for black¬
smith’s vices (first revision)
1630 : 1984
Specification for Mason’s
tools for plaster work and
pointing work (first
revision)
2722 : 1964
Specification for portable
swing weigh batchers for
concrete (single and double
bucket type)
1759 : 1986
Specification for Powrahs
(second revision)
2852 : 1998
Specification for carpenters
augers (first revision )
1791 : 1985
Specification for batch type
concrete mixers (second
revision)
3066 : 1965
3251 : 1965
Specification for hot
asphalt mixing plants
Specification for asphalt
1930 : 2003
Woodworking tools —
Chisels and gouges (third
paver finisher
revision)
Specification for engineer’s
3365 : 1965
Specification for floor
1931 : 2000
polishing machines
files (third revision)
3559 : 1966
Specification for pneumatic
2028 : 2004
Specification for open jaw
concrete breakers
wrenches (spanners)
(fourth revision)
3587 : 1986
Specification for rasps
(second revision)
2029 : 1998
Specification for ring
wrenches (spanners)
(fourth revision)
3650 : 1981
Specification for
combination side cutting
pliers (second revision)
2030 : 1989
Specification for box
spanners (second revision)
3938 : 1983
Specification for electric
wire rope hoists (second
2094
Specification for heater for
revision)
bitumen (tar) and emulsion
(second revision)
4003
Specification for pipe
wrenches
(Part 1) : 1996
Specification (second
revision)
(Part 1) : 1978
General purposes (first
revision)
(Part 2) : 1999
Bitumen sprayer (third
(Part 2) : 1986
Heavy duty (first revision)
revision)
PAJRT 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
73
1992
1991
1967
1967
1992
1968
1969
1969
1969
1969
1969
1986
1998
1990
1970
1970
1970
1994
2004
1970
1971
1971
Title
Specification for carpenters
squares (first revision )
Specification for pincers
(second revision )
Specification for metal
hand rammers
Specification for steel
wheel barrows (with two
wheels)
Specification for open
ended slugging wrenches
(spanners) (first revision )
Specification for welders
chipping hammer
Specification for glass
pliers
Specification for fencing
pliers
Specification for wire
stripping pliers
Specification for cross cut
and rip saws
Specification for tenon and
dovetail saws
Specification for hack-saw
frames (first revision )
Specification for bolt
clippers (first revision )
Specification for snipenose
pliers (first revision )
Specification for brick and
mason’s chisels
Specification for pipe vices
(chain type)
Specification for ripping
chisels
Specification for vibratory
plate compactor (first
revision )
Mobile hot mix asphalt
plants, light duty —
Requirements (first
revision )
Specification for hand-
operated concrete mixer
Specification for pipe grip
pliers
Specification for pipe vices
(hinged type)
IS No.
Title
6078 : 1986
Specification for Lineman’s
pliers (second revision )
6087 : 1971
Specification for metal
cutting shears
6118 : 1991
Specification for multiple
slip joint pliers (first
revision)
6149 : 1984
Specification for single
ended open jaw adjustable
wrenches ((first revision )
6375 : 1991
Specification for wood
splitting wedges (first
revision)
6389 : 1998
Specification for
combination wrenches with
equal openings (second
revision)
6428 : 1972
Specification for pile frame
6430 : 1985
Specification for mobile air
compressor for construct¬
ion purposes (first revision)
6433 : 1972
Specification for guniting
equipment
6546 : 1989
Specification for claw
hammers (first revision)
6836 : 1973
Specification for hand
snaps and set-ups for solid
rivets
6837 : 1973
Specification for three
wheel type pipe cutter
6841 : 1973
Specification for wrecking
bars
6861 : 1973
Specification for engineers’
scrapers
6881 : 1973
Specification for link type
pipe cutters
6891 : 1973
Specification for
carpenter’s auger bits
6892 : 1973
Specification for black¬
smith’s brick-iron
7041 : 1973
Specification for
carpenter’s plain brace
7042 : 1973
Specification for
carpenter’s ratchet brace
7077 : 1973
Specification for bending
bars
7958 : 1976
Specification for hand vices
8202 : 1999
Specification for car¬
penter’s wooden bodied
planes (first revision)
NATIONAL BUILDING CODE OF INDIA 2016
IS No.
8671 : 1977
(50) 7293 : 1974
(51) 4130 : 1991
(52) 13935 : 2009
(53) 13828 : 1993
Title
IS No.
Title
Specification for nail puller
Safety code for working
with construction
machinery
Safety code for demolition
of buildings ( second
revision)
Guidelines for repair and
seismic strengthening of
masonry buildings (first
revision)
Improving earthquake
resistance of low strength
masonry buildings —
Guidelines
(54) 13827 : 1993
(55) 15988 : 2013
(56) 13727 : 1993
(57) 2470 (Part 1) :
1985
(58) 10500 : 2012
Improving earthquake
resistance of earthen
buildings — Guidelines
Seismic evaluation and
strengthening of existing
reinforced concrete
buildings — Guidelines
Guidelines for
requirements of cluster
planning for housing
Code of practice for
installation of septic
tanks: Part 1 design, criteria
and construction (second
revision)
Specification for drinking
water (second revision)
PART 7 CONSTURCTION MANAGEMENT, PRACTICES AND SAFETY
75
NATIONAL BUILDING CODE OF INDIA
PART 8 BUILDING SERVICES
Section 1 Lighting and Natural Ventilation
BUREAU OF INDIAN STANDARDS
CONTENTS
FOREWORD ... 3
1 SCOPE ... 5
2 TERMINOLOGY ... 5
3 ORIENTATION OF BUILDING ... 8
4 LIGHTING ... 11
5 VENTILATION ... 35
ANNEX A METHOD OF CALCULATING SOLAR LOAD ON VERTICAL ... 46
SURFACES OF DIFFERENT ORIENTATION
ANNEX B SKY COMPONENT TABLES ... 49
LIST OF STANDARDS ... 55
b-
2
NATIONAL BUILDING CODE OF INDIA 2016
National Building Code Sectional Committee, CED 46
it
FOREWORD >
This Code (Part 8/Section 1) covers requirements and methods for lighting and natural ventilation of buildings.
Illumination levels for different tasks are recommended to be achieved either by daylighting or artificial lighting
or a combination of both. This Section, read together with Part 8 ‘Building Services, Section 2 Electrical and
Allied Installations’ of the Code, adequately covers the illumination levels required and methods of achieving the
same.
Ventilation requirements to maintain air quality and control body odours in terms of air changes per hour and to
ensure thermal comfort and heat balance of body are laid for different occupancies and the methods of achieving
the same by natural means are covered in this Section. The provisions on mechanical ventilation Sre covered in
Part 8 ‘Building Services, Section 3 Air conditioning, Heating and Mechanical Ventilation’ of the Code.
Climatic factors which normally help in deciding the orientation of the buildings to get desirable benefits of
lighting and natural ventilation inside the buildings are also covered in this Section.
This Section was first published in 1970. The first revision of the Section was brought out in 1983. In the second
revision, some provisions were updated based on the information given in the SP 41: 1987 ‘Handbook on functional
requirements of buildings (other than industrial buildings)’; other major changes in the last revision included
rationalization of definitions and inclusion of definitions for some more terms; inclusion of climatic classification
map of India based on a new criteria; updating of data on total solar radiations incident on various surfaces of
buildings for summer and winter seasons; inclusion of design guidelines >for natural ventilation; reference to
Part 8 ‘Building Services, Section 3 Air Conditioning, Heating and Mechanical Ventilation’ of the Code for
guidelines on mechanical ventilation, was made, where these provisions were covered exhaustively; inclusion of
rationalized method for estimation of desired capacity of ceiling fans and their optimum height above the floor for
rooms of different sizes; incorporation of design sky illuminance values for different climatic zones of India, etc.
Energy efficiency was another important aspect which was taken care of in the last revision of the Code. Accordingly,
the relevant requirements for energy efficient system for lighting and natural ventilation were duly included in the
concerned provisions under the Section.
As a result of experience gained on implementation of 2005 version of the Code and feedback data received, a
need was felt to revise this Section. This draft revision has, therefore, been formulated to take care of these. The
significant changes incorporated in this revision are:
a) Calculation for solar load has been elaborated, and a detailed ‘Method of Calculating Solar Load on
Vertical Surfaces in Different Orientation’ has been added in Annex A, supporting the relevant provisions.
b) Detailed provisions on sky component calculation procedure have been included along with examples in
Annex B supporting the relevant clauses.
c) Reference to SP 41 : 1987 for obtaining coefficient utilization for determination of luminous flux has
been included.
d) Provisions relating to efficient artificial light source and luminaires have been updated.
e) Modem lighting techniques such as LED and induction light have been included vis-a-vis their energy
consumption.
f) Provisions relating to photocontrols for artificial lights have been updated.
g) Definitions and enabling provision for lighting shelves and light pipes have been included.
h) Provisions related to thermal comfort clause have been elaborated including therein indices such as
effective temperature, adaptive thermal comfort along with elaborations on tropical summer index.
j) Design guidelines for natural ventilation have been elaborated with illustrations.
k) Provisions related to determination of rate of ventilation, particularly on combined effect of wind and
thermal actions, have been elaborated.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
3
m) Provision on colour rendering has been included in line with that in SP 72 : 2010 ‘National Lighting
Code 2010’.
n) Various other existing provisions have been updated based on the latest technical developments in the
field.
The provisions of this Section are without prejudice to the various acts, rules and regulations including the Factories
Act, 1948 and rules and regulations framed thereunder.
The information contained in this Section is largely based on the following Indian Standards/Special Publications:
IS 2440 : 1975
IS 3103 : 1975
IS 3362 : 1977
IS 3646 (Part 1)
IS 7662 (Part 1)
IS 11907 : 1986
SP 32 : 1986
SP 41 : 1987
Guide for daylighting of buildings ( second revision)
Code of practice for industrial ventilation (first revision)
Code of practice for natural ventilation of residential buildings (first revision)
1992 Code of practice for interior illumination: Part 1 General requirements and
recommendations for working interiors (first revision)
1974 Recommendations for orientation of buildings : Part 1 Non-industrial buildings
Recommendations for calculation of solar radiation on buildings
Handbook on functional requirements of industrial buildings (lighting and ventilation)
Handbook on functional requirements of buildings other than industrial buildings
Provisions given in National Lighting Code, ‘SP 72 : 2010’ may also be referred.
The following publication has also been referred to in the formulation of this Section:
Report on energy conservation in buildings, submitted to Department of Power, Ministry of Energy by CSIR-
Central Building Research Institute, Roorkee.
All standards, whether given herein above or cross-referred to in the main text of this Section, are subject to
revision. The parties to agreement based on this Section are encouraged to investigate the possibility of applying
the most recent editions of the standards.
For the purpose of deciding whether a particular requirement of this Section is complied with, the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1 960
‘Rules for rounding off numerical values (revised)'. The number of significant places retained in the rounded off
value should be the same as that of the specified value in this Section.
4
NATIONAL BUILDING CODE OF INDIA 2016
NATIONAL BUILDING CODE OF INDIA
PART 8 BUILDING SERVICES
Section 1 Lighting and Natural Ventilation
1 SCOPE
1.1 This Code (Part 8/Section 1) covers requirements
and methods for lighting and natural ventilation of
buildings.
1.2 The provisions in respect of lighting and ventilation
in sustainable buildings are covered in Part 1 1
‘Approach to Sustainability’ of the Code which shall
be used in conjunction with this Section.
1.3 For all buildings and facilities open to and used by
the public, including all forms of public housing by the
government/civic bodies and private developers,
adequate lighting and ventilation for barrier, free access
and movement within and around buildings by elderly
and persons with disabilities shall be ensured in
accordance with 13 of Part 3 ‘Development Control
Rules and General Building Requirements’ of the Code.
2 TERMINOLOGY
For the purpose of this Section, the definitions given
below shall apply.
2.1 Lighting
2.1.1 Altitude (9) — The angular distance of any point
of celestial sphere, measured from the horizon, on the
great circle passing through the body and the zenith
( see Fig. 1).
2.1.2 Azimuth (O) — The angle measured between
meridians passing through the north point and the point
in question (point C in Fig. 1).
2.1.3 Brightness Ratio or Contrast — The variations
or contrast in brightness of the details of a visual task,
such as white print on blackboard.
2.1.4 Candela (cd) — The SI unit of luminous intensity.
Candela = 1 lumen per steradian
2.1.5 Central Field — The area of circle around the
point of fixation and its diameter, subtending an angle
of about 2° at the eye. Objects within this area are most
critically seen in both their details and colour.
2.1.6 Clear Design Sky — The distribution of
luminance of such a sky is non-uniform; the horizon is
brighter than the zenith, and when Lz is the brightness
at zenith, the brightness at an altitude (0) in the region
away from the sun, is given by the expression:
Ze = Lz cosec 0 (for 15° < 9 < 90°)
Z0 = Lz cosec 15° (for 0° < 0 < 15°) = 3.863 7 Lz
2.1.7 Colour Rendering Index (CRI) — Measure of
the degree to which the psychophysical colour of an
Z
REFERENCES
O - Observer’s station S - Geographical south
C - Celesuai body E - Geographical east
Z - Zenith W - Geographical west
NA - Nadir N - Geographical north
Fig. 1 Altitude and Azimuth of a
Celestial Body
object illuminated by the test illuminant conforms to
that of the same object illuminated by the reference
illuminant, suitable allowance having been made for
the state of chromatic adaptation.
2.1.8 Correlated Colour Temperature (CCT) (K) —
The temperature of the Planckian radiator whose
perceived colour most closely resembles that of a given
stimulus at the same brightness and under specified
viewing conditions.
2.1.9 Daylight Area — The superficial area on the
working plane illuminated to not less than a specified
daylight factor, that is, the area within the relevant
contour.
2.1.10 Daylight Factor — The measure of total
daylight illuminance at a point on a given plane
expressed as the ratio (or percentage) which the
illuminance at the point on the given plane bears to the
simultaneous illuminance on a horizontal plane due to
clear design sky at an exterior point open to the whole
sky vault, direct sunlight being excluded.
2.1.11 Daylight Penetration — The maximum distance
to which a given daylight factor contour penetrates into
a room.
2.1.12 Direct Solar Illuminance — The illuminance
from the sun without taking into account the light from
the sky.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
5
2.1.13 External Reflected Component (ERCj — The
ratio (or percentage) of that part of the daylight
illuminance at a point on a given plane which is received
by direct reflection from external surfaces as compared
to the simultaneous exterior illuminance on a horizontal
plane from the entire hemisphere of an unobstructed
clear design sky.
2.1.14 Glare — A condition of vision in which there
is discomfort or a reduction in the ability to see
significant objects or both due to an unsuitable
distribution or range of luminance or due to extreme
contrasts in space and time.
2.1.15 Illuminance — At a point on a surface, the ratio
of the luminous flux incident on an infinitesimal element
of the surface containing the point under consideration
to the area of the element.
NOTE — The unit of illuminance (the measurement of
illumination) is lux which is 1 lumen per m2.
2.1.16 Internal Reflected Component (IRC) — The
ratio (or percentage) of that part of the daylight
illuminance at a point in a given plane which is received
by direct reflection or inter-reflection from the internal
surfaces as compared to the simultaneous exterior
illuminance on a horizontal plane due to the entire
hemisphere of an unobstructed clear design sky.
2.1.17 Light Output Ratio (LOR) or Efficiency (r)) —
The ratio of the luminous flux emitted from the
luminaire to that emitted from the lamp(s) (nominal
luminous flux). It is expressed in percent.
2.1.18 Light Pipe — A conduit made of a highly
reflective material, which is capable of channeling light
from one end to the other through successive internal
reflections. Such a pipe may be flexible or rigid.
2.1.19 Light Shelf — A daylighting system based on
sun path geometry used to bounce the light off a ceiling,
project it deeper into a space, distribute it from above,
and diffuse it to produce a uniform light level below.
2.1.20 Lumen (lm) — SI unit of luminous flux. The
luminous flux emitted within unit solid angle (one
steradian) by a point source having a uniform intensity
of one candela.
2.1.21 Luminance (At a point of a Surface in a Given
Direction ) (Brightness) — The quotient of the luminous
intensity in the given direction of an infinitesimal
element of the surface containing the point under
consideration by the orthogonally projected area of the
element on a plane perpendicular to the given direction.
The unit is candela per square metre (cd/m2).
2.1.22 Luminous Flux ((f)) — The quantity
characteristic of radiant flux which expresses its
capacity to produce visual sensation evaluated
according to the values of relative luminous efficiency
for the light adapted eye:
a) Effective Luminous Flux (<})n) — Total luminous
flux which reaches the working plane.
b) Nominal Luminous Flux (<j)o) — Total luminous
flux of the light sources in the interior.
2.1.23 Maintenance Factor (d) — The ratio of the
average illuminance on the working plane after a certain
period of use of a lighting installation to the average
illuminance obtained under the same conditions for a
new installation.
2.1.24 Meridian — It is the great circle passing through
the zenith and nadir for a given point of observation.
2.1.25 North and South Points — The point in the
respective directions where the meridian cuts the
horizon.
2.1.26 Orientation of Buildings — In the case of non¬
square buildings, orientation refers to the direction of
the normal to the long axis. For example, if the length of
the building is east-west, its orientation is north-south.
2.1.27 Peripheral Field — It is the rest of the visual
field which enables the observer to be aware of the
spatial framework surrounding the object seen.
NOTE — A central part of the peripheral field, subtending an
angle of about 30° on either side of the point of fixation, is
chiefly involved in the perception of glare.
2.1.28 Reflected Glare — The variety of ill effects on
visual efficiency and comfort produced by unwanted
reflections in and around the task area.
2.1.29 Reflection Factor (Reflectance) — The ratio
of the luminous flux reflected by a body (with or without
diffusion) to the flux it receives. Some symbols used
for reflection factor are:
rc = reflection factor of ceiling.
rw = reflection factor of parts of the wall between
the working surface and the luminaires.
r{ = reflection factor of floor.
2.1.30 Reveal — The side of an opening for a window.
2.1.31 Room Index (kT) — An index relating to the
shape of a rectangular interior, according to the formula:
k L.W
r~(L + W)Hm
where L and W are the length and width respectively of
the interior, and Hm is the mounting height, that is,
height of the fittings above the working plane.
NOTES
1 For rooms where the length exceeds 5 times the width, L
shall be taken as L = 5 W.
2 If the reflection factor of the upper stretch of the walls is less
than half the reflection factor ol the ceiling, for indirect or for
the greater part of indirect lighting, the value Hm is measured
between the ceiling and the working plane
6
NATIONAL BUILDING CODE OF INDIA 2016
2.1.32 Sky Component (SC) — The ratio (or
percentage) of that part of the daylight illuminance at a
point on a given plane which is received directly from
the sky as compared to the simultaneous exterior
illuminance on a horizontal plane from the entire
hemisphere of an unobstructed clear design sky.
2.1.33 Solar Load — The amount of heat received
into a building due to solar radiation which is affected
by orientation, materials of construction and reflection
of external finishes and colour.
2.1.34 Utilization Factor (Coefficient of Utilization)
(l i) — The ratio of the total luminous flux which reaches
the working plane (effective luminous flux, (}>n) to the
total luminous flux of the light sources in the interior
(nominal luminous flux, (j)0).
2.1.35 Visual Field — The visual field in the binocular
which includes an area approximately 120° vertically
and 1 60° horizontally centering on the point to which
the eyes are directed. The line joining the point of
fixation and the centre of the pupil of each eye is called
its primary line of sight.
2.1.36 Working Plane — A horizontal plane at a level
at which work will normally be done (see 4. 1.4.3
and 4.1.4.4).
2.2 Ventilation
2.2.1 Air Change per Hour — The amount of air
leakage into or out of a building or room in terms of
the number of times the building volume or room
volume exchanged.
2.2.2 Axial Flow Fan — A fan having a casing in which
the air enters and leaves the impeller in a direction
substantially parallel to its axis.
2.2.3 Centrifugal Fan — A fan in which the air leaves
the impeller in a direction substantially at right angles
to its axis.
2.2.4 Contaminants — Dusts, fumes, gases, mists,
vapours and such other substances present in air that
are likely to be injurious or offensive to the occupants.
2.2.5 Dilution Ventilation — Supply of outside air to
reduce the airborne concentration of contaminants in
the building.
2.2.6 Dry Bulb Temperature — The temperature of
the air, read on a thermometer, taken in such a way so
as to avoid errors due to radiation.
2.2.7 Effective Temperature (ET) — An arbitrary index
which combines into a single value the effect of
temperature, humidity and air movement on the
sensation of warmth or cold felt by the human body
and its numerical value is that of the temperature of
still saturated air which would induce an identical
sensation.
2.2.8 Exhaust of Air — Removal of air from a building
or a room and its disposal outside by means of a
mechanical device, such as a fan.
2.2.9 Fresh Air or Outside Air — Air of that quality,
which meets the criteria of Table 1 and in addition
shall be such that the concentration of any contaminant
in the air is limited to within one-tenth the threshold
limit value (TLV) of that contaminant.
NOTES
1 Where it is reasonably believed that the air of quality is not
expected as indicated above, sampling and analysis shall be
carried out by a competent authority having jurisdiction and if
the outside air of the specified quality is not available, filtration
and other treatment devices shall be used to bring its quality to
or above the levels mentioned in Table 1 .
Odour is to be essentially unobjectionable.
2 The above list of contaminants is not exhaustive and available
special literature may be referred for data on other contaminants.
Table 1 Maximum Allowable Contaminant
Concentrations for Ventilation Air
(Clause 2.2.9)
SI Contaminants Annual Short Averaging
No. Average Term Level Period
(Arithmetic
(Not to
Mean)
Exceed
More than
pg/m3
Once a
Year)
pg/m3
h
(1)
(2)
(3)
(4)
(2)
i)
Suspended
particulates
60
150
24
ii)
Sulphur oxides
80
400
24
lii)
Carbon monoxide
20 000
30 000
8
iv)
Photochemical
oxidant
100
500
1
v)
Hydrocarbons (not
including methanes)
I 800
4 000
3
vi)
Nitrogen oxide
200
500
24
2.2.10 General Ventilation —
Ventilation,
either
natural or mechanical or both, so as to improve the
general environment of the building, as opposed to local
exhaust ventilation for contamination control.
2.2.11 Globe Temperature — The temperature
measured by a thermometer whose bulb is enclosed in
a matt black painted thin copper globe of 150 mm
diameter. It combines the influence of air temperature
and thermal radiations received or emitted by the
bounding surfaces.
2.2.12 Humidification — The process whereby the
absolute humidity of the air in a building is maintained
at a higher level than that of outside air or at a level
higher than that w'hich would prevail naturally.
2.2. 1 3 Humidity, Absolute — The mass of water vapour
4
per unit volume.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
7
2.2.14 Humidity. Relative — The ratio of the partial
pressure or density of the water vapour in the air to the
saturated pressure or density, respectively of water
vapour at the same temperature.
2.2.15 Local Exhaust Ventilation — Ventilation effected
bv exhaust of air through an exhaust appliance, such as
a hood with or without fan located as closely as possible
to the point at which contaminants are released, so as to
capture effectively the contaminants and convey them
through ducts to a safe point of discharge.
2.2.16 Make-Up Air — Outside air supplied into a
building to replace the indoor air.
2.2.17 Mechanical Ventilation — Supply of outside
air either by positive ventilation or by infiltration by
reduction of pressure inside due to exhaust of air, or by
a combination of positive ventilation and exhaust of
air.
2.2.18 Natural Ventilation — Supply of outside air
into a building through window or other openings due
to wind outside and convection effects arising from
temperature or vapour pressure differences (or both)
between inside and outside of the building.
2.2.19 Positive Ventilation — The supply of outside
air by means of a mechanical device, such as a fan.
2.2.20 Propeller Fan — A fan in which the air leaves
the impeller in a direction substantially parallel to its
axis designed to operate normally under free inlet and
outlet conditions.
2.2.21 Spray-Head System — A system of atomizing
water so as to introduce free moisture directly into a
building.
2.2.22 Stack Effect — Convection effect arising from
temperature or vapour pressure difference (or both)
between outside and inside of the room and the difference
of height between the outlet and inlet openings.
2.2.23 Tropical Summer Index (TSI) — The
temperature of calm air at 50 percent relative humidity
which imparts the same thermal sensation as the given
environment.
2.2.24 Threshold Limit Value (TL V) — Refers to airborne
concentration of contaminants currently accepted by the
American Conference of Governmental Industrial
Hygienists and represents conditions under which it is
believed that nearly all occupants may be repeatedly
exposed, day after day, without adverse effect.
2.2.25 Velocity', Capture — Air velocity at any point
in front of the exhaust hood necessary to overcome
opposing air currents and to capture the contaminants
in air at that point by causing the air to flow into the
exhaust hood.
2.2.26 Ventilation — Supply of outside air into, or the
removal of inside air from an enclosed space.
2.2.27 Wet Bulb Temperature — The steady
temperature finally given by a thermometer having its
bulb covered with gauze or muslin moistened with
distilled water and placed in an air stream of not less
than 4.5 m/s.
3 ORIENTATION OF BUILDING
3.1 The chief aim of orientation of buildings is to
provide physically and psychologically comfortable
living inside the building by creating conditions which
suitably and successfully ward off the undesirable
effects of severe weather to a considerable extent by
judicious use of the recommendations and knowledge
of climatic factors.
3.2 Basic Zones
3.2.1 For the purpose of design of buildings, the
country may be divided into the major climatic zones
as given in Table 2, which also gives the basis of this
classification.
Table 2 Classification of Climate
(' Clause 3.2.1)
SI
Climatic Zone
Mean Monthly
Mean Monthly
No.
Maximum
Relative
Temperature
Humidity
°C
Percent
(1)
(2)
(3)
(4)
i)
Hot-dry
Above 30
Below 55
H)
Warm-humid
Above 30
Above 55
Above 25
Above 75
Hi)
Temperate
25-30
Below 75
iv)
Cold
Below 25
All values
v)
Composite
see 3.2.2
The climatic classification map of India is shown in
Fig. 2.
3.2.2 Each climatic zone does not have same climate
for the whole year; it has a particular season for more
than six months and may experience other seasons for
the remaining period. A climatic zone that does not have
any season for more than six months may be called as
composite zone.
3.3 Climatic Factors
From the point of view of lighting and natural
ventilation, the following climatic factors influence the
optimum orientation of the building:
a) Solar radiation and temperature,
b) Relative humidity, and
c) Prevailing winds.
8
NATIONAL BUILDING CODE OF INDIA 2016
The interstate boundaries between Arunachal Pradesh. Assam and Meghalaya shown on this map are as interpreted
from the North-Eastern Areas (Reorganization) Act. 1971 , but have yet to be verified.
The external boundaries and coastlines of India agree with the Record/Master Copy certified by Survey of India.
The responsibility for the correctness of internal details rest with the publisher.
Fig. 2 Climatic Zones of India
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
9
3.4 Solar Radiation
3.4.1 The best orientation from solar point of view
requires that the building as a whole should receive the
maximum solar radiation in winter and the minimum
in summer. For practical evaluation, it is necessary to
know the duration of sunshine, and hourly solar
intensity on the various external surfaces on
representative days of the seasons. The total direct plus
diffused diurnal solar loads per unit area on vertical
surface facing different directions are given in Table 3
for two days in the year, that is, 22 June and 22
December, representative of summer and winter, for
latitudes corresponding to some important cities all over
India. From Table 3, the total heat intake can be
calculated for all possible orientations of the building
for these extreme days of summer and winter. Solar
load on vertical surfaces of different orientation can
be calculated as per the method given in Annex A.
3.4.1 .1 Except in cold climatic zone, suitable sun-breakers
have to be provided to cut off the incursion of direct
sunlight to prevent heat radiation and to avoid glare.
3.5 Relative Humidity and Prevailing Winds
3.5.1 The discomfort due to high relative humidity in
air when temperatures are also high can be
counteracted, to a great extent, by circulation of air
with electric fans or by ventilation. In the past,
simultaneously with heavy construction and
surrounding Verandahs to counter the effect of sun’s
radiation, there was also an over emphasis on prevailing
winds to minimise the adverse effects of high humidity
with high temperatures. With the introduction of electric
fan to effectively circulate air and owing to taking into
account the rise in cost of construction of buildings,
emphasis should be placed on protection from solar
radiation where temperatures are very high. When,
however, there is less diurnal variation between
morning and mean maximum temperatures along with
high humidity, as in coastal areas, the emphasis should
be on prevailing winds.
3. 5.1.1 For the purpose of orientation, it is necessary
to study the velocity and direction of the wind at each
hour and in each month instead of relying on
generalizations of a month or a period or for the year
as a whole. This helps to spot the right winds for a
particular period of day or night.
3. 5. 1.2 It is generally found that variation up to 30°
with respect to the prevalent wind direction does not
materially affect indoor ventilation (average indoor air
speed) inside the building.
3.5.2 In hot-dry climate, advantage can be taken of
evaporative cooling in summer to cool the air before
introducing it into the building. But in warm humid
climate, it is desirable either to regulate the rate of air
movement with the aid of electric fans or to take
advantage of prevailing winds.
3.6 Aspects of Daylighting
Since the clear design sky concept for daylighting takes
care of the worst possible situation, orientation is not a
major problem for daylighting in buildings, except that
Table 3 Total Solar Radiation (Direct Plus Diffused) Incident on Various Surfaces of
Buildings, in W/m2/day, for Summer and for Winter Seasons
(' Clause 3.4.1)
SI
No.
Orientation
(1)
(2)
Latitude
9°N
(3)
13°N
(4)
17°N
(5)
21 °N
(6)
25 °N
(7)
29°N
(8)
it
North
Summer
1 494
1 251
2 102
1 775
2 173
1 927
Winter
873
859
840
825
802
765
u)
North-East
Summer
2 836
2717
3 144
3 092
3 294
3 189
Winter
1 240
1 158
1 068
1 001
912
835
in)
East
Summer
3 344
3 361
3 475
3 598
3 703
3 794
Winter
2 800
2 673
2 525
2 409
2211
2 055
iv)
South-East
Summer
2 492
2 660
2 393
2 629
2 586
2 735
Winter
3 936
3 980
3 980
3 995
3 892
3 818
V)
South
Summer
1 009
1 185
1 035
1 1 17
1 112
1 350
Winter
4 674
4 847
4 958
5 059
4 942
4 981
Vl)
South-West
Summer
2 492'-
2 660
2 393
2 629
2 586
2 735
Winter
3 936
3 980
3 980
3 995
3 892
3 818
vii)
West
Summer
3 341
3 361
3 475
3 598
3 703
3 794
Winter
2 800
2 673
2 525
2 409
2211
2 055
viii)
North-West
Summer
2 836
2717
3 144
3 092
3 294
3 189
Winter
1 240
1 158
1 068
1 001
912
835
IX)
Horizontal
Summer
8 107
8 139
8 379
8 553
8 817
8 863
Winter
6 409
6 040
5 615
5 231
4 748
4 281
10
NATIONAL BUILDING CODE OF INDIA 2016
direct sunshine and glare should be avoided. However,
due allowance should be given to the mutual shading
effects of opposite facades.
3.7 Planting of Trees
Planting of trees in streets and in open spaces should be
done carefully to take advantage of both shades and
sunshine without handicapping the flow of natural winds.
Their advantage in abating glare and in providing cool
and/or warm pockets in developed areas should also be
taken. Some trees shed leaves in winter while retaining
thick foliage in summer. Such trees will be very
advantageous, particularly where southern and western
exposures are concerned, by allowing maximum sun
during winter and effectively blocking it in summer.
3.8 For detailed information regarding orientation of
buildings and recommendations for various climatic
zones of country, reference may be made to good
practice [8-1(1)].
4 LIGHTING
4.1 Principles of Lighting
4.1.1 Aims of Good Lighting
Good lighting is necessary for all buildings and has
three primary aims. The first aim is to promote work
and other activities carried out within the building; the
second aim is to promote the safety of the people using
the building; and the third aim is to create, in
conjunction with the structure and decoration, a
pleasing environment conducive to interest of the
occupants and a sense of their well-being.
4.1. 1.1 Realization of these aims involves the following:
a) Careful planning of the brightness and colour
pattern within both the working areas and the
surroundings so that attention is drawn naturally
to the important areas, detail is seen quickly
and accurately and the room is free from any
sense of gloom or monotony {see 4.1.4);
b) Using directional lighting, where appropriate,
to assist perception of task detail and to give
good modeling;
c) Controlling direct and reflected glare from
light sources to eliminate visual discomfort;
d) In artificial lighting installations, minimizing
flicker from certain types of lamps and paying
attention to the colour rendering properties of
the light;
e) Correlating lighting throughout the building to
prevent excessive differences between adjacent
areas so as to reduce the risk of accidents; and
f) Installing emergency lighting systems, where
necessary.
4.1.2 Planning the Brightness Pattern
The brightness pattern seen within an interior may be
considered as composed of three main parts — the task
itself, immediate background of the task and the general
surroundings of walls, ceiling, floor, equipment and
furnishings.
4. 1.2.1 In occupations where the visual demands are
small, the levels of illumination derived from a criterion
of visual performance alone may be too low to satisfy
the other requirements. For such situations, therefore,
illuminance recommendations are based on standards
of welfare, safety and amenity judged appropriate to the
occupations; they are also sufficient to give these tasks
brightness which ensured that the visual performance
exceeds the specified minimum. Unless there are special
circumstances associated with the occupation, it is
recommended that the illuminance of all working areas
within a building should generally be 150 lux.
4. 1.2.2 Where work takes place over the whole
utilizable area of room, the illumination over that area
should be reasonably uniform and it is recommended
that the uniformity ratio (minimum illuminance divided
by average illuminance levels) should be not less than
0.7 for the working area.
4. 1.2.3 When the task brightness appropriate to an
occupation has been determined, the brightness of the
other parts of the room should be planned to give a
proper emphasis to visual comfort and interest.
A general guide for the brightness relationship within
the normal field of vision should be as follows:
a) For high task brightness Maximum
(above 100 cd/m2):
1 ) Between the visual task and 3 : 1
the adjacent areas like table tops
2) Between the visual task and 10:1
the remote areas of the room
b) For low and medium task brightness (below
100 cd/m2): The task should be brighter than
both the background and the surroundings; the
lower the task brightness, the less critical is
the relationship.
4.1.2.4 In case of all buildings and facilities open to
and used by the public including all torms of public
housing by the govemment/civic bodies and private
developers, the requirements for visual contrast as given
in 13 and Annex B of Part 3 ‘Development Control
and Rules and General Building Requirements’ of the
Code shall also be complied with for ensuring visual
comfort for elders and persons with disabilities.
4.1.3 Glare
Excessive contrast or abrupt and large changes in
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL V ENTILATION
11
brightness produce the effect of glare. When glare is
present, the efficiency of vision is reduced and small
details or subtle changes in scene cannot be perceived.
It may be,
a) direct glare due to light sources within the field
of vision;
b) reflected glare due to reflections from light
sources or surfaces of excessive brightness;
and
c) veiling glare where the peripheral field is
comparatively very bright.
4.1.3. 1 An example of glare sources in daylighting is
the view of the bright sky through a window or skylight,
especially when the surrounding wall or ceiling is
comparatively dark or weakly illuminated. Glare can
be minimised in this case either by shielding the open
sky from direct sight by louvers, external hoods or deep
reveals, curtains or other shading devices or by cross
lighting the surroundings to a comparable level. A
gradual transition of brightness from one portion to the
other within the field of vision always avoids or
minimises the discomfort from glare.
For electric lamps the minimum shielding angles for
lamp luminance shall not be less than the values given
in the table below:
Lamp Luminance Minimum Shielding Angle
ked/m2 Degree
1 to 20 10
20 to 50 15
50 to 500 20
> 500 30
The above mentioned shielding angle should not be
applied to luminaires that do not appear in the field of
view of a worker during usual work and/or do not give
the worker any noticeable disability glare.
Table 4 also gives recommended value of quality class
of direct glare limitation for different tasks. These are
numbers assigned to qualitative limits of direct glare:
high, medium and low quality as 1 , 2 and 3, respectively.
For more details reference may be made to good
practice [8-1(2)].
4.1.4 Recommended Values of Illuminance
Table 4 gives recommended values of illuminance
commensurate with the general standards of lighting
described in this Section and related to many
occupations and buildings. These are valid under most
of the conditions whether the illumination is by
daylighting, artificial lighting or a combination of the
two. The great variety of visual tasks makes it
impossible to list them all and those given should be
regarded as representing types of task.
4. 1.4.1 The different locations and tasks are grouped
within the following four sections:
a) Industrial buildings and process;
b) Offices, schools and public buildings;
c) Surgeries and hospitals; and
d) Hotels, restaurants, shops and homes.
4. 1.4.2 The illumination levels recommended in
Table 4 are those to be maintained at all time on the
task. As circumstances may be significantly different
for different interiors used for the same application or
for different conditions for the same kind of activity, a
range of illuminances is recommended for each type
of interior or activity instead of a single value of
illuminance. Each range consists of three successive
steps of the recommended scale of illuminances. They
represent good practice and should be regarded as
giving order of illumination commonly required rather
than as having some absolute significance. For working
interiors the middle value of each range represents the
recommended service illuminance that would be used
unless one or more of the factors mentioned below
apply.
4. 1 .4.2. 1 The higher value of the range should be used
when,
a) unusually low reflectances or contrasts are
present in the task;
b) errors are costly to rectify;
c) visual work is critical;
d) accuracy or higher productivity is of great
importance; and
e) visual capacity of the worker makes it
necessary.
4.1. 4.2.2 The lower value of the range may be used when,
a) reflectances or contrast are unusually high;
b) speed and accuracy is not important; and
c) the task is executed only occasionally.
4. 1.4.3 Where a visual task is required to be carried
out throughout an interior, general illumination level
to the recommended value on the working plane is
necessary; where the precise height and location of the
task are not known or cannot be easily specified, the
recommended value is that on horizontal plane 850 mm
above floor level.
NOTE — For an industrial task, working plane for the purpose
of general illumination levels is that on a work place which is
generally 750 mm above the floor level. For certain purposes,
such as viewing the objects of arts, the illumination levels
recommended are for the vertical plane at which the art pieces
are placed.
4.1. 4.4 Where the task is localized, the recommended
value is that for the task only; it need not, and sometimes
should not, be the general level of illumination used
12
NATIONAL BUILDING CODE OF INDIA 2016
throughout the interior. Some processes, such as
industrial inspection process, call for lighting of
specialized design, in which case the level of illumination
is only one of the several factors to be taken into account.
4. 1.4. 5 In case of all buildings and facilities open to
and used by the public, including all forms of public
housing by the govemment/civic bodies and private
developers, the minimum luminance level as given in
13 and Annex B of Part 3 'Development Control Rules
and General Building Requirements' of the Code shall
also be complied with for ensuring sufficient lighting
for accessibility by elders and persons with disabilities.
4.1.5 Lighting for Movement About a Building
Most buildings are complexes of working areas and
other areas, such as passages, corridors, stairways,
lobbies and entrances. The lighting of all these areas
shall be properly correlated to give safe movement
within the building at all times.
In case of all buildings and facilities open to and used
by the public, including all forms of public housing by
the govemment/civic bodies and private developers, the
illuminance in these areas shall comply with
requirements given in 13 and Annex B of Part 3
‘Development Control Rules and General Building
Requirements’ of the Code.
4.1.5. 1 Corridors, passages and stairways
Accidents may result if people leave a well-lighted
working area and pass immediately into corridors or
on to stairways where the lighting is inadequate, as the
time needed for adaptation to the lower level may be
too long to permit obstacles or the treads of stairs to be
seen sufficiently quickly. For the same reason, it is
desirable that the illumination level of rooms which
open off a working area should be fairly high even
though the rooms may be used only occasionally.
It is important, when lighting stairways, to prevent
disability from glare caused by direct sight of bright
sources to emphasize the edges of the treads and to
avoid confusing shadows. The same precautions should
be taken in the lighting of catwalks and stairways on
outdoor industrial plants.
4.1. 5.2 Entrances
The problems of correctly grading the lighting within
a building to allow adequate time for adaptation when
passing from one area to another area are particularly
acute at building entrances. These are given below:
a) By day, people entering a building will be
adapted to the very high levels of brightness
usually present outdoors and there is risk of
accident if entrance areas, particularly any
steps, are poorly lighted. This problem may
often be overcome by arranging windows to
give adequate natural lighting at the immediate
entrance, grading to lower levels further inside
the entrance area. Where this cannot be done,
supplementary artificial lighting should be
installed to raise the level of illumination to
an appropriate value.
b) At night it is desirable to light entrance halls and
lobbies so that the illumination level reduces
towards the exit and so that no bright fittings are
in the line of sight of people leaving the building.
Any entrance steps to the building should be
well-lighted by con'ectly screened fittings.
4.1.6 Colour Rendering
The colour appearance of light and its colour rendering
capability are different aspects of the light sources. A
faithful reproduction of an object colour depends on
the colour rendering capability of the light source. In
1965 International Commission on Illumination (CIE)
developed a quantitative method of assignment of
colour rendering property, and is denoted as Colour
Rendering Index (CRI).
CRI is arrived at by a test by which a number of specified
samples are tested under a standard or reference light
source and the chromaticity coordinate are plotted on
the IE triangle as given in Fig. 7 of Part 2 ‘Physics of
Light, Section 3 Colour’ of National Lighting Code 2010.
The same test is repeated under the source under test
and corresponding chromaticity coordinate are plotted
on the same plot. The difference between the position of
each sample for test and standard source is measured to
scale. The general colour rendering index (Ra) is
obtained by the average value for eight samples ( see
Fig. 8 of Part 2 ‘Physics of Light, Section 3 Colour’ of
National Lighting Code 2010). For perfect agreement
of colour, the R1 value should be 100. In general:
Ra = 1/ (R1 + R2 + R3 + R4 + . + R8)
The specific colour rendering index for an individual
sample is given by:
Ri = 100 - 4.6AEi
where
AEi = chromaticity shift on the CIE chromaticity
diagram for each sample.
From the obtained value of Ra, as calculated above,
the colour rendering shall be evaluated as mentioned
in the following table:
Colour Rendering
Ra (General Colour
Evaluated
Rendering Index)
True
90-100
Good
70-90
Moderate
50-70
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
13
Table 4 Recommended Values of Illuminance
( Clauses 4. 1.3.1, 4.1.4, 4. 1.4. 2, 4.3.2 and 4.3.2. 1)
SI No.
Type of Interior or Activity
Range of
Quality Class
Remarks
Service
of Direct
Illuminance
Glare
(See Note)
Limitation
lux
(See Note)
(1)
(2)
(3)
(4)
(5)
1
AGRICULTURE AND
HORTICULTURE
1.1
Inspection of Farm Produce where
Colour is Important
300-500-750
1
Local lighting may be appropriate
Other Important Tasks
200-300-500
2
Local lighting may be appropriate
1.2
Farm Workshops
1.2.1
General
50-100-150
3
1.2.2
Workbench or machine
200-300-500
2
Local or portable lighting may be appropriate
1.3
Milk Premises
50-100-150
3
1.4
Sick Animal Pets, Calf Nurseries
30-50-100
3
1.5
Other Firm and Horticultural Buildings
20-30-50
3
2
COAL MINING (SURFACE
BUILDINGS)
2.1
Coal Preparation Plant
2.1.1
Walkways, floors under conveyors
30-50-100
3
2.1.2
Wagon loading, bunkers
30-50-100
3
2.13
Elevators, chute transfer pits, wash box
50-100-150
3
area
2.1.4
Drum filters, screen, rotating shafts
100-150-200
3
2.1.5
Picking belts
150-200-300
3
Directional and colour properties of lighting
may be important for easy recognition of coal
and rock
2.2
Lamp Rooms
2.2.1
Repair section
200-300-500
2
2.2.2
Other areas
100-150-200
3
23
Weight Cabins, Fan Houses
100-150-200
3
2.4
Winding Houses
100-150-200
3
3
ELECTRICITY GENERATION,
TRANSMISSION AND
DISTRIBUTION
3.1
General Plant
3.1.1
Turbine houses (operating floor)
150-200-300
2
3.1.2
Boiler and turbine house basements
50-100-150
3
3.13
Boiler houses, platforms, areas around
burners
50-100-150
3
3.1.4
Switch rooms, meter rooms, oil plant
rooms, HV substations (indoor)
100-150-200
2
3.1.5
Control rooms
200-300-500
1
Localized lighting of control display and the
control desks may be appropriate
3.1.6
Relay and telecommunication rooms
200-300-500
2
3.1.7
Diesel generator rooms, compressor
100-150-200
3
rooms
3.1.8
Pump houses, water treatment plant
houses
100-150-200
3
3.1.9
Battery rooms, chargers, rectifiers
50-100-150
3
3.1.10
Precipitator chambers, platforms, etc
50-100-150
3
3.1.11
Cable tunnels and basements,
circulating water culverts and screen
chambers, storage tanks (indoor),
operating areas and filling points at
outdoor tanks
30-50-100
3
3.2
Coal Plant
3.2.1
Conveyors, gantries, junction towers,
unloading hoppers, ash handling plants,
settling pits, dust hoppers outlets
50-100-150
3
3.2.2
Other areas where operators may be in
attendance
100-150-200
3
14
NATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( Continued )
0)
(2)
(3)
(4)
(5)
3.3
Nuclear Plants
Gas Circulation Bays, Reactor Area,
Boiler Platform, Reactor Charges and
Discharge Face
100-150-200
2
4
METAL MANUFACTURE
4.1
Iron Making
4.1.1
Sinter plant:
Plant floor
150-200-300
3
Mixer drum, fan house, screen houses,
coolers, transfer stations
100-150-200
3
4.1.2
Furnaces, cupola:
General
100-150-200
3
Control platforms
200-300-500
2
Local lighting may be appropriate
Conveyor galleries, walkways
30-50-100
3
4.2
Steel Making
4.2.1
Electric melting shops
150-200-300
3
4.2.2
Basic oxygen steel making plants
4.2.2.1
General
100-150-200
3
4.2.2.2
Convertor floor, teeming bay
150-200-300
3
4.2.2.3
Control platforms
200-300-500
2
Local lighting may be appropriate
4.2.2.4
Scrap bays
100-150-200
3
4.3
Metal Forming and Treatment
4.3.1
Ingot stripping, soaking pits, annealing
and heat treatment bays, acid recovery
plant Picking and cleaning bays,
roughing mills, cold mills, finishing
mills, tinning and galvanizing lines, cut
up and rewind lines
150-200-300
3
4.3.2
General
100-150-200
3
4.3.3
Control platforms
200-300-500
2
Local lighting may be appropriate
43.4
Wire mills, product finishing, steel
inspection and treatment
200-300-500
3
4.3.5
Plate/strip inspection
300-500-700
2
4.3.6
Inspection of tin plate, stainless steel.
-
-
Special lighting to reveal faults in the specular
etc
surface of the material will be required
4.4
Foundries
4.4.1
Automatic plant
4.4.1. 1
Without manual operation
30-50-100
3
4.4.1.2
With occasional manual operation
100-150-200
3
4.4.1.3
With continuous manual operation
150-200-300
3
4.4.1.4
Control room
200-300-500
1
Localized lighting of the control display and
the control desks may be appropriate
4.4.13
Control platforms
200-300-500
2
4.4.2
Non-automatic plants
4.4.2.1
Charging floor, pouring, shaking out,
cleaning, grinding fettling
200-300-500
3
4.4.2.2
Rough moulding, rough core making
200-300-500
3
4.4.23
Fine moulding, fine core making
300-500-750
2
4.4.2.4
Inspection
300-500-750
2
43
Forges (Severe vibration is likely to
occur)
43.1
General
200-300-500
2
43.2
Inspection
300-500-750
2
5
CERAMICS
5.1
Concrete Products
Mixing, Casting, Cleaning
150-200-300
3
5.2
Potteries
5.2.1
Grinding, moulding, pressing, cleaning,
trimming, glazing, firing
200-300-500
3
5.2.2
Enamelling, colouring
500-750-1 000
1
5.3
Glass Works
5.3.1
Furnace rooms, bending, annealing
100-150-200
3
5.3.2
Mixing rooms, forming, cutting,
grinding, polishing, toughening
200-300-500
3
5.3.3
Beveling, decorative cutting, etching,
silvering
300-500-750
2
5.3.4
Inspection
300-500-750
2
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
15
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
(5)
6
CHEMICALS
6.1
Petroleum, Chemical and Petrochemical
Works
6.1.1
Exterior walkways, platforms, stairs
and ladders
30-50-100
3
6.1.2
Exterior pump and valve areas
50-100-150
3
6.1.3
Pump and compressor houses
100-150-200
3
6.1.4
Process plant with remote control
30-50-100
3
6.1.5
Process plant requiring occasional
manual intervention
50-100-150
3
6.1.6
Permanently occupied work stations in
process plant
150-200-300
3
6.1.7
Control rooms for process plant
200-300-500
1
6.2
Pharmaceutical Manufacturer and Fine
Chemicals Manufacturer
6.2.1
Pharmaceutical manufacturer grinding,
granulating, mixing, drying, tableting,
sterilizing, washing, preparation of
solutions, filling, capping, wrapping,
hardening
300-500-750
2
6.2.2
Fine chemical manufacture
6.2.2.1
Exterior walkways, platforms, stairs and
ladders
30-50-100
3
6.2.2 .2
Process plant
50-100-150
3
6.2.23
Fine chemical finishing
300-500-750
2
6.2.2.4
Inspection
300-500-750
1
Local fighting may be appropriate
6.3
Soap Manufacture
63.1
General area
200-300-500
2
6.3.2
Automatic processes
100-200-300
2
6.3.3
Control panels
200-300-500
1
Local lighting may be appropriate
6.3.4
Machines
200-300-500
2
6.4
Paint Works
6.4.1
General
200-300-500
2
6.4.2
Automatic processes
150-200-300
2
6.43
Control panels
200-300-500
2
6.4.4
Special batch mixing
500-750-1 000
2
6.4.5
Colour matching
750-1 000-1 500
1
7
MECHANICAL ENGINEERING
7.1
Structural Steel Fabrication
7.1.1
General
200-300-500
3
7.1.2
Marking off
300-500-750
3
Local fighting may be appropriate
7.2
Sheet Metal Works
7.2.1
Pressing, punching, shearing, stamping,
spinning, folding
300-500-750
2
7.2.2
Benchwork, scribing, inspection
500-750-1 000
2
7.3
Machine and Tool Shops
7.3.1
Rough bench and machine work
200-300-500
3
73.2
Medium bench and machine work
300-500-750
2
73.3
Fine bench and machine work
500-750-1 000
2
7.3.4
Gauge rooms
750-1000-1 500
1
Optica] aids may be required
7.4
Die Sinking Shops
7.4.1
General
300-500-750
2
7.4.2
Fine work
1 000-1 500-2 000
1
Flexible local fighting is desirable
7.5
Welding and Soldering Shops
7.5.1
Gas and arc welding, rough spot
welding
200-300-500
3
7.5.2
Medium soldering, brazing, spot welding
300-500-750
3
7.5.3
Fine soldering, fine spot welding
750-1 000-1 500
2
Local lighting is desirable
7.6
Assembly Shops
7.6.1
Rough work for example, frame and
200-300-500
3
The fighting of vertical surface may
heavy machine assembly
important
7.6.2
Medium work, for example, engine
assembly, vehicle body assembly
300-500-750
2
7.6.3
Fine work, for example, office
machinery assembly
500-750-1 000
1
Localized fighting may be useful
7.6.4
Very fine work, for example,
instrument assembly
750-1 000-1 500
1
Local fighting and optical aids are desirable
7.6.5
Minute work, for example, watch making
1 000-1 500-2 000
1
Local fighting and optical aids are desirable
16
NATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
(5)
7.7
Inspection and Testing Shops
7.7.1
Coarse work, for example, using go/no
go gauges, inspection of large sub-
assemblies
300-500-750
2
Local or localized lighting may be appropriate
7.7.2
Medium work, for example, inspection
of painted surfaces
500-750-1 000
1
Local or localized lighting may be appropriate
7.7.3
Fine work, for example, using
calibrated scales, inspection of
precision mechanisms
750-1 000-1 500
1
Local or localized lighting may be appropriate
7.7.4
Very fine work, for example,
inspection of small intricate parts
1 000-1 500-2 000
1
Local lighting and optical aids are desirable
7.7.5
Minute work, for example, inspection
of very small instruments
2 000
1
Local lighting and optical aids are desirable
7.8
Points Shops and Spray Booths
7.8.1
Dipping, rough spraying
200-300-500
3
7.8.2
Preparation, ordinary painting,
spraying and finishing
200-500-750
2
7.8.3
Fine painting, spraying and finishing
500-750-1 000
2
7.8.4
Inspection, retouching and matching
750-1 000-1 500
2
7.9
Plating Shops
7.9.1
Vats and baths
200-300-500
3
7.9.2
Buffing, polishing burnishing
300-500-750
2
7.9.3
Final buffing and polishing
500-750-1 000
2
7.9.4
Inspection
“
—
Special light to reveal fault in the surface of
the material will be required
8
ELECTRICAL AND ELECTRONIC
ENGINEERING
8.1
Electrical Equipment Manufacture
8.1.1
Manufacture of cables and insulated
wires, winding, varnishing and
immersion of coils, assembly of large
machines, simple assembly work
200-300-500
3
8.1.2
Medium assembly, for example,
telephones, small motors
300-500-750
3
Local lighting may be appropriate
8.1.3
Assembly of precision components, for
750-1 000-1 500
1
Local lighting is desirable. Optical aids may
example, telecommunication
equipment, adjustment, inspection and
calibration
be useful
8.1.4
Assembly of high precision parts
1 000-1 500-2 000
1
Local lighting is desirable. Optical aids may
be useful
8.2
Electronic Equipment Manufacture
8.2.1
Printed circuit board
8.2.1. 1
Silk screening
300-500-750
1
Local lighting may be appropriate
8.2.1.2
Hand insertion of comp< nents,
soldering
500-750-1 000
1
Local lighting may be appropriate
8.2.1.3
Inspection
750-1 000-1 500
1
A large, low luminance luminaire overhead
ensures specular reflection conditions which
are helpful for inspection of printed circuits
8.2. 1.4
Assembly of wiring harness, cleating
harness, testing and calibration
500-750-1 000
1
Local lighting may be appropriated.
8.2. 1.5
Chassis assembly
750-1 000-1 500
1
Local lighting may be appropriated.
8.2.2
Inspection and testing
8.2.2.1
Soak test
150-200-300
2
8.2.2.2
Safety and functional tests
200-300-500
9
z.
9
FOOD, DRINK AND TOBACCO
9.1
Slaughter Houses
9.1.1
General
200-300-500
3
9.1.2
Inspection
300-500-750
2
9.2
Canning, Preserving and Freezing
9.2.1
Grading and sorting of raw materials
500-750-1 000
2
Lamp of colour rendering group 1A or IB
will be required, if colour judgement is
required
9.2.2
Preparation
300-500-750
3
9.2.3
Canned and bottled goods
9.2.3. 1
Retorts
200-300-500
3
9.2.3.2
Automatic processes
150-200-300
3
9.2.3.3
Labelling and packaging
200-300-500
3
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
17
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
(5)
9.2.4
Frozen foods
9.2.4. 1
Process area
200-300-500
3
9.2.4.2
Packaging and storage
200-300-500
9.3
Bottling. Brewing and Distilling
9..U
Keg washing and handling, bottle
washing
150-200-300
3
9.3.2
Keg inspection
200-300-500
3
9.3.3
Bottle inspection
Special lighting will be required
9.3.4
Process areas
200-300-500
3
9.3.5
Bottle filling
500-750-1 000
3
9.4
Edible Oils and Fats Processing
9.4.1
Refining and blending
200-300-500
3
9.4.2
Production
300-500-750
->
9.5
Mills-Milling, Filtering and Packing
200-300-500
3
9.6
Bakeries
9.6.1
General
200-300-500
9
9.6.2
Hand decorating, icing
300-500-750
2
9.7
Chocolate and Confectionery
Manufacture
9.7.1
General
200-300-500
3
9.7.2
Automatic processes
150-200-300
3
9.7.3
Hand decoration, inspection, wrapping
300-500-750
2
If accurate colour judgements are required.
and packing
lamps of colour rendering group 1A or IB are
used
9.8
Tobacco Processing
9.8.1
Material preparation, making and
packing
300-500-750
2
10
TEXTILES
10.1
Fibre Preparation
10.1.1
Bale breaking, washing
200-300-500
3
10.1.2
Stock dyeing, tinting
200-300-500
3
10.2
Yam Manufacture
10.2.1
Spinning, roving, winding, etc
300-500-750
2
10.2.2
Healding (drawing in)
750-1000-750
2
10.3
Fabric Production
10.3.1
Knitting
300-500-750
2
10.3.2
Weaving
10.3.2.1
Jute and hemp
200-300-500
■ 2
10.3.2.2
Heavy woolens
300-500-750
1
10.3.2.3
Medium worsteds, fine woolens,
cottons
500-750-1 000
1
10.3.2.4
Fine worsteds, tine linens, synthetics
750-1 000-1 500-
1
10.3.2.5
Mending
1 000-1 500-2 000
1
103.2.6
Inspection
1 000-1 500-2 000
1
10.4
Fabric Finishing
10.4.1
Dyeing
200-300-500
3
10.4.2
Calendaring, chemical treatment, etc
300-500-750
2
10.4.3
Inspection
10.4.3.1
'Grey’ cloth
750-1 000-1 500
1
10.4.3.2
Final
1 000-1 500-2 000
1
10.5
Carpet Manufacture
10.5.1
Winding, beaming
200-300-500
3
10.5.2
Setting pattern, turfing cropping,
trimming, fringing, latexing and latex
drying
300-500-750
2
10.5.3 .
Designing, weaving, mending
500-750-1 000
2
10.5.4
Inspection
10.5.4.1
General
750-1 000- 1 500
1
Local lighting may be appropriate
10.5.4.2
Piece dyeing
500-750-1000 •
1
Local lighting may be appropriate
11
LEATHER INDUSTRY
HI !
Leather Manufacture
11.1.1 1
Cleaning, tanning and stretching, vats,
cutting, fleshing, stuffing
200-300-500
3
11.1.2
Finishing, scarfing
300-500-750
1
4
11.2
Leather Working
11.2.1
General
200-300-500
3
11.2.2
Pressing, glazing
300-500-750
2
N ATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( Continued )
U)
(2)
(3)
(4)
(3)
11.2.3
Cutting, splitting, scarfing, sewing
500-750-1 000
2
Directional lighting may be useful.
l 1.2.4
Grading, matching
~)
Local lighting may be appropriate
12
CLOTHING AND FOOTWEAR
12.1
Clothing Manufacture
12.1.1
Preparation of doth
200-300-500
12.1.2
Cutting
500-750-1 000
i
12.1.3
Matching
500-750-1 000
i
12.1.4
Sewing
750-1 000-1 500
i
12.1.5
Pressing
300-500-750
2
12.1.6
Inspection
1 000-1 500-2 000
i
Local lighting may be appropriate
12.1.7
Hand tailoring
1 000-1 500-2 000
i
Local lighting may be appropriate
12.2
Hosiery and Knitwear Manufacture
12.2.1
Flat bed knitting machines
300-500-750
i
Mil
Circular knitting machines
500-750-1000
n
12.2.3
Lockstitch and overlocking machine
750-1 000-1 500
i
12.2.4
Linking or running on
750-1 000-1 500
i
12.2.5
Mending, handfinishing
1 000-1 500-3 000
-
Local lighting may be appropriate
12.2.6
Inspection
1 000- 1 500-2 000
2
Local lighting may be appropriate
12.3
Glove Manufacture
12.3.1
Sorting and grading
500-750-1 000
i
12.3.2
Pressing, knitting, cutting
300-500-750
2
12.3.3
Sewing
500-750-1 000
O
12.3.4
Inspection
1 000-1 500-2 000
-
Local lighting may be appropriate
12.4
Hat Manufacture
12.4.1
Stiffening, braiding, refining, forming,
sizing, pounding, ironing
200-300-500
2
12.4.2
Cleaning, flanging, finishing
300-500-750
2
12.4.3
Sewing
500-750-1000
2
12.4.4
Inspection
1 000-1 500-2 000
-
Local lighting may be appropriate
12.5
Boot and Shoe Manufacture
12.5.1
Leather and synthetics
12.5.2
Sorting and grading
750-1 000-1 500
1
12.5.3
Clicking, closing
750-1 000-1 500
2
Local or localized lighting may be appropriate
12.5.4
Preparatory' operations
750-1 000-1 500
2
Local or localized lighting may be appropriate
12.5.5
Cutting tables and pressure
1 000-1 500-2 000
1
Local or localized lighting may be appropriate
12.5.6
Bottom stock preparation, lasting,
bottoming finishing, shoe rooms
750-1 000-1 500
1
Local or localized lighting may be appropriate
12.5.7
Rubber
12.5.7.1
Washing, compounding, coating,
drying, varnishing, vulcanizing,
calendaring, cutting
200-300-500
3
12.5.7.2
Lining, making and finishing
300-500-750
2
13
TIMBER AND FURNITURE
13.1
Sawmills
13.1.1
General
150-200-300
3
13.1.2
Head saw
300-500-750
2
Localized lighting may be appropriate
13.1.3
Grading
500-750-1 000
2
Directional lighting may be useful
13.2
Woodwork Shops
13.2.1
Rough sawing, bench work
200-300-500
2
13.2.2
Sizing, planning, sanding, medium
machining and bench work
300-500-750
2
13.2.3
Fine bench and machine work, fine
sanding, finishing
500-750-1 000
2
Localized lighting may be appropriate
13.3
Furniture Manufacture
13.3.1
Raw material stores
50-100-150
3
13.3.2
Finished goods stores
100-150-200
J
13.3.3
Wood matching and assembly, rough
sawing, cutting
200-300-500
2
13.3.4
Machining, sanding and assembly,
polishing
300-500-750
2
Localized lighting may be appropriate
13.3.5
Tool room
300-500-750
2
13.3.6
Spray booths
13.3.6.1
Colour finishing
Mi >->00-750
2
13.3.6.2
Clear finishing
200-300-500
2
13.3.7
Cabinet making
13.3.7.1
Veneer sorting and grading
750-1 (K)0-1 500
i
13.3.7.2
Marquetry', pressing, patching and fitting
300-500-750
i
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
19
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
13.3.7.3
Final inspection
500-750-1 000
1
13.4
Upholstery Manufacture
13.4.1
Cloth inspection
1 000-1 500-2 000
1
13.4.2
Filling, covering
300-500-750
2
13.4.3
Slipping, cutting, sewing
500-750-1 000
2
13.4.4
Mattress making
13.4.5
Assembly
300-500-750
2
13.4.6
Tape edging
750-1 000-1 500
2
14
PAPER AND PRINTING
14.1
Paper Mills
14.1.1
Pulp mills, preparation plants
200-300-500
3
14.1.2
Paper and board making
14.1.2.1
General
200-300-500
3
14.1.2.2
Automatic process
150-200-300
3
14.1.2.3
Inspection, sorting
300-500-750
1
14.1.3
Paper converting processes
14.1.3.1
General
200-300-500
3
14.1.3.2
Associated printing
300-500-750
2
14.2
Printing Works
14.2.1
Type foundries
14.2.1.1
Matrix making, dressing type, hand and
machine coating
200-300-500
3
14.2.1.2
Front assembly, sorting
500-750-1 000
2
14.2.2
Composing rooms
14.2.2.1
Hand composing, imposition and
distribution
500-750-1 000
1
14.2.2.2
Hot metal keyboard
500-750-1 000
1
14.2.2.3
Hot metal casting
200-300-500
2
14.2.2.4
Photo composing keyboard or setters
300-500-750
1
14.2.2.5
Paste up
500-750-1 000
1
14.2.2.6
Illuminated tables - general lighting
200-300-500
14.2.2.7
Proof presses
300-500-750
2
14.2.2.8
Proof reading
500-750-1 000
1
14.2.3
Graphic Reproduction
14.2.3.1
General
300-500-750
2
14.2.3.2
Precision proofing, retouching, etching
750-1 000-1 500
1
14.2.3.3
Colour reproduction and inspection
750-1 000-1 500
1
14.2.4
Printing machine room
14.2.4.1
Presses
300-500-750
2
14.2.4.2
Premake ready
300-500-750
2
14.2.4.3
Printed sheet inspection
750-1 000-1 500
1
14.2.5
Binding
14.2.5.1
Folding, pasting, punching and
stitching
300-500-750
2
14.2.5.2
Cutting, assembling, embossing
500-750-1 000
2
15
PLASTIC AND RUBBER
15.1
Plastic Products
15.1.1
Automatic plant
15.1.1.1
Without manual control
30-50-100
3
15.1.1.2
With occasional manual control
50-100-150
3
15.1.1.3
With continuous manual control
200-300-500
3
15.1.1.4
Control rooms
200-300-500
1
15.1.1.5
Control platforms
200-300-500
2
15.1.2
Non-automatic plant
15.1.2.1
Mixing, calendaring, extrusion,
injection, compression and blow
moulding, sheet fabrication
200-300-500
3
15.1.2.2
Trimming, cutting, polishing,
cementing
300-500-750
2
15.1.2.3
Printing, inspection
750-1 000-1 500
1
15.2
Rubber Products
15.2.1
Stock preparation - plasticizing,
milling
150-200-300
3
15.2.2
Calendaring, fabric preparation, stock¬
cutting
300-500-750
3
_ (5)
Special lighting will be required
Special lighting will be required
Local lighting may be appropriate
Supplementary lighting may be necessary for
maintenance work
Dimming may be required
Local lighting may be appropriate
Local lighting may be appropriate
20
NATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
(5)
15.2.3
Extruding, moulding
300-500-750
2
15.2.4
Inspection
750-1 000-1 500
-
16
16.1
16.1.1
DISTRIBUTION AND STORAGE
Work Stores
100-150-200
3
Avoid glare to drivers of vehicles approaching
the loading bay
Unpacking, sorting
150-200-300
3
Avoid glare to drivers of vehicles approaching
the loading bay
16.1.2
Large item storage
50-100-150
3
Avoid glare to drivers of vehicles approaching
the loading bay
16.1.3
Small item rack storage
200-300-500
3
Avoid glare to drivers of vehicles approaching
the loading bay
16.1.4
Issue counter, records, storeman’s desk
300-500-750
2
Local or localized lighting may be appropriate
16.2
Warehouses and Bulk Stores
16.2.1
Storage of goods where indentification
requires only limited preparation of
detail
50-100-150
3
16.2.2
Storage of goods where identification
requires perception of detail
100-150-200
3
16.2.3
Automatic high bay rack stores
16.2.3.1
Gangway
20
16.2.3.2
Control station
150-200-300
3
16.2.3.3
Packing and dispatch
200-300-500
3
16.2.3.4
Loading bays
100-150-200
3
Avoid glare to drivers of vehicles approaching
the loading bay
16.3
Cold Stores
16.3.1
General
200-300-500
3
16.3.2
Breakdown, make-up and dispatch
200-300-500
3
16.3.3
Loading bays
100-150-200
3
Avoid glare to drivers of vehicles approaching
the loading bay
17
COMMERCE
17.1
Offices
17.1.1
General offices
300-500-750
1
17.1.2
Deep plan general offices
500-750-1000
1
17.1.3
Computer work stations
300-500-750
1
17.1.4
Conference rooms, executive offices
300-500-750
1
17.1.5
Computer and data preparation rooms
300-500-750
1
171.6
Filing rooms
200-300-500
1
17.2
Drawing Offices
17.2.1
General
300-500-750
1
17.2.2
Drawing boards
500-750-1 000
1
17.2.3
Computer aided design and drafting
Special lighting is required
17.2.4
Print rooms
200-300-500
1
17.3
Banks and Building Societies
17.3.1
Counter, office area
300-500-750
1
17.3.2
Public area
200-300-500
1
18
SERVICES
18.1
Garages
18.1.1
Interior parking areas
20-30-50
3
18.1.2
General repairs, servicing, washing,
polishing
200-300-500
2
V.
18.1.3
Workbench
300-500-750
1
Local or localized lighting may be appropriate
18.1.4
Spray booths
300-500-750
1
18.1.5
External apron
18.1.5.1
Genera]
30-50-100
Care should be taken to avoid glare to drivers
and neighbouring residents
18.1.5.2
Pump area (retail sales)
200-300-500
See 'Retailing’
18.2
Appliance servicing
18.2.1
Workshop
18.2.1.1
General
200-300-500
2
18.2.1.2
Workbench
300-500-750
2
Localized lighting may be appropriate
18.2.1.3
Counter
200-300-500
2
Localized lighting may be appropriate
18.2.1.4
Stores
200-300-500
3
18.3
Laundries
18.3.1
Commercial laundries
18.3.2
Receiving, sorting, washing, drying,
ironing, despatch, dry-cleaning, bulk
machine work
200-300-500
3
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
21
Table 4 — ( Continued )
(1)
3)
(3)
(4)
(5)
18.3.3
Head ironing, pressing, mending,
spotting, inspection
300-500-750
3
18.3.4
Launderettes
200-300-500
3
18.4
Sewage Treatment Works
18.4.1
Walkways
30-50-100
3
18.4.2
Process areas
50-100-150
3
19
RETAILING
The service illuminance should be provided
19.1
Small Shops with Counters
300-500-750
1
on the horizontal plane of the counter. Where
19.2
Small Self-Service Shops with Island
300-500-750
1
wall displays are used, a similar illuminance
Displays
on the walls is desirable
19.3
Super Markets, Hyper-Markets
19.3.1
General
300-500-750
2
19.3.2
Checkout
300-500-750
2
19.3.3
Showroom for large objects, for
example, cars, furniture
300-500-750
1
19.3.4
Shopping precincts and arcades
100-150-200
2
20
PLACES OF PUBLIC ASSEMBLY
20.1
Public Rooms, Village Halls, Worship
Halls
200-300-500
1
20.2
Concert Halls, Cinemas and Theatres
20.2.1
Foyer
150-200-300
20.2.2
Booking office
200-300-500
Local or localized lighting may be appropriate
20.23
Auditorium
50-100-150
Dimming facilities will be necessary. Special
lighting of the aisles is desirable
20.2.4
Dressing rooms
200-300-500
Special mirror lighting for make-up may be
required
20.2.5
Projection room
100-150-200
203
Churches
203.1
Body of church
100-150-200
2
203.2
Pulpit, lectern
200-300-500
2
Use local lighting
203.3
Choir stalls
200-300-500
2
Local lighting may be appropriate
203.4
Alter, communion table, chance!
100-150-200
2
Additional lighting to provide emphasis is
desirable
20.33
Vestries
100-150-200
2
203.6
Organ
200-300-500
20.4
Hospitals
20.4.1
Anaesthetic rooms
20.4.1.1
General
200-300-500
20.4.1.2
Local
750-1 000-1 500
20.4.2
Consulting areas
20.43.1
General
200-300-500
20.4.2.2
Examination
750-1 000-1 500
20.4.3
Corridors
20.4.3.1
General
100-150-200
20.4.4
Ward corridors
20.4.4.1
Day, screened from bays
150-200-300
20.4.4.2
Day, open to natural light
150-200-300
(total)
20.4.4.3
Moming/evening
100-150-200
20.4.4.4
Night
5-10
20.4.5
Cubicles
20.4.5.1
General
200-300-500
20.4.5.2
Treatment
750-1 000-1 500
20.4.6
Examination
20.4.6.1
General
200-300-500
20.4.6.2
Local inspertion
750-1 000-1 500
20.4.7
Intensive therapy
20.4.7.1
Bad head
30-50
20.4.7.2
Circulation between bed ends
50-100-150
20.4.7.3
Observation
200-300-500
20.4.7.4
Local observation
750-1 000-1 500
20.4.7.5
Staff base (day)
200-300-500
20.4.7.6
Staff base (night)
30
20.4.8
Laboratories
20.4.8.1
General
200-300-500
20.4.8.2
Examination
300-500-750
20.4.9
Nurses’ stations
22
NATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( C on turned)
(1)
(2)
(3)
(4)
(5)
20.4.9.1
Moming/duy/evening
200-300-500
20.4.9.2
Night desks
30
20.4.9.3
Night, medical trolleys
50-100-150
20.4.10
Operating theatres
20.4.10.1
General
300-500-750
20.4.10.2
Local
10 000 to 50 000
Special operating lights are used.
20.4.11
Pathology departments
20.4.11.1
General
200-300-500
20.4.11.2
Examination
300-500-750
20.4.11.3
Pharmacies
200-300-500
20.4.11.4
Reception/enquiry
200-300-500
20.4.11.5
Recovery rooms
200-300-500
20.4.12
Ward-circulation
20.4.12.1
Day
50-100-150
20.4.12.2
Moming/evening
50-100-150
20.4.12.3
Night
3-5
20.4.13
Ward -bed head
20.4.13.1
Moming/evening
30-50
20.4.13.2
Reading
100-150-200
20.4.14
Night
20.4.14.1
Adult
0.1-1
20.4.14.2
Pediatric
1
20.4.143
Psychiatric
1-5
20.4.14.4
Watch
5
20.4.15
X-Ray areas
20.4.15.1
General
150-200-300
20.4.15.2
Diagnostic
150-200-300
20.4.153
Operative
200-300-500
20.4.15.4
Process dark room
50
20.4.16
Surgeries
20.4.16.1
General
200-300-500
20.4.16.2
Waiting rooms
100-150-200
20.4.17
Dental surgeries
20.4.17.1
Chair
Special lighting
20.4.17.2
Laboratories
300-500-750
20.4.18
Consulting rooms
20.4.18.1
General
200-300-500
20.4.18.2
Desk
300-500-750
20.4.183
Examination couch
300-500-750
20.4.18.4
Ophthalmic wall and near-vision charts
300-500-750
20.5
Hotels
20.5.1
Entrance halls
50-100-150
20.5.2
Reception, cashier’s and porters’ desks
200-300-500
Localized lighting may be appropriate.
20.5.3
Bars, coffee base, dining rooms, grill
50-200
The lighting should be designed to create an
rooms, restaurants, lounges
appropriate atmosphere
20.5.4
Cloak rooms, baggage rooms
50-100-150
3
20.5.5
Bed rooms
30-50-100
Supplementary local lighting at the bed head,
writing table should be provided
20.5.6
Bathroom
50-100-150
Supplementary local lighting near the minror
is desirable
20.5.7
Food preparation and stores, cellars,
lifts and corridors
See 'General Building Areas’
20.6
Libraries
20.6.1
Lending library
20.6.1.1
General
200-300-500
1
20.6.1.2
Counters
300-500-750
1
Localized lighting may be appropriate.
20.6.1.3
Bookshelves
100-150-200
2
The sendee illuminance should be provided
on ihe vertical face at the bottom of the
bookstack
20.6.1.4
Reading rooms
200-300-500
1
20.6.1.5
Reading tables
200-300-500
1
Localized lighting may be appropriate
20.6.2
Catalogues
20.6.2.1
Card
100-150-200
2
20.6.2.2
Microfiche/Visual display units
100-150-200
2
20.63
Reference libraries
20.63.1
General
200-300-500
1
20.6.3.2
Counters
300-500-750
1
Localized lighting may be appropriate.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
23
Table 4 — ( Continued )
(1)
(2)
(3)
(4)
(5)
20.6.3.3
Bookshelves
100-150-200
2
The service illuminance should be provided
on a vertical surface at the foot of the
bookshelves
20.6.3.4
Study tables, carrels
300-500-750
i
20.6.3.5
Map room
200-300-500
i
20.6.4
Display and exhibition areas
20.6.4.1
Exhibits insensitive to light
200-300-500
20.6.4.2
Exhibit sensitive to light, for example,
pictures, prints, rare books in archives
50 to 150
20.6.5
Library workrooms
20.6.5.1
Book repair and binding
300-500-750
2
20.6.5.2
Catalogue and sorting
300-500-750
2
20.6.5.3
Remote book stores
100-150-200
3
20.7
Museums and Art Galleries
20.7.1
Exhibits insensitive to light
200-300-500
20.7.2
Light sensitive exhibits, for example.
150
This is a maximum illuminance to be
oil and temper paints, undyed leather,
bone, ivory, wood, etc
provided on the principal plane of the exhibit
20.7.3
Extremely light sensitive exhibits, for
50
This is the maximum illuminance to be
example, textiles, water colours, prints
and drawings, skins, botanical
specimens, etc
provided on the principal plane of the object
20.7.4
Conservation studies and workshops
300-500-750
1
20.8
Sports Facilities
Multi-purpose sports halls
300-750
This lighting system should be sufficiently
flexible to provide lighting suitable for the
variety of sports and activities that take place
in sports halls. Higher illuminance of 1000-
2000 lux would be required for television
coverage
21
EDUCATION
21.1
Assembly Halls
21.1.1
General
200-300-500
3
21.1.2
Platform and stage
Special lighting to provide emphasis and to
facilitate the use of the platform/ stage is
desirable
21.2
Teaching Spaces
General
200-300-500
1
2l„5
Lecture Theatres
21.3.1
General
200-300-500
1
21.3.2
Demonstration benches
300-500-750
1
Localized lighting may be appropriate
21.4
Seminar Rooms
300-500-750
1
21.5
Art Rooms
300-500-750
1
21.6
Needlework Rooms
300-500-750
1
21.7
Laboratories
300-500-750
1
21.8
Libraries
200-300-500
1
21.9
Music Rooms
200-300-500
1
21.10
Sports Halls
200-300-500
1
21.11
Workshops
200-300-500
1
22
TRANSPORT
22.1
Airports
22.1.1
Ticket counters, checking desks, and
information desks
300-500-750
2
Localized lighting may be appropriate
22.1.2
Departure lounges, other waiting areas
150-200-300
2
22.1.3
Baggage reclaim
150-200-300
2
22.1.4
Baggage handling
50-100-150
2
22.1.5
Customs and immigration halls
300-500-750
2
22.1.6
Concourse
150-200-300
2
22.2
Railway Stations
22.2.1
Ticket office
300-500-750
2
Localized lighting may be appropriate
22.2.2
Information office
300-500-750
2
Localized lighting over the counter may be
appropriate
22.2.3
Parcels office, left
22.2.4
Luggage office
22.2.4.1
General
50-100-150
2
22.2.4.2
Counter
150-200-300
2
22.2.5
Waiting rooms
150-200-300
2
22.2.6
Concourse
150-200-300
2
24
NATIONAL BUILDING CODE OF INDIA 2016
Table 4 — ( Concluded )
(1)
(2)
(3)
(4)
(5)
22.2.7
22.2.8
22.2.9
Time table
Ticket barriers
Platforms (covered)
150-200-300
150-200-300
30-50-100
2
2
2
Localized lighting may be appropriate
Localized lighting may be appropriate
Care should be taken to light and mark the
22.2.10
Platforms (open)
20
edge of the platform clearly
Care should be taken to light and mark the
22.3
Coach Stations
edge of the platform clearly
22.3.1
Ticket offices
300-500-750
2
Localized lighting over the counter may be
22.3.2
Information offices
300-500-750
2
appropriate
Localized lighting over the counter may be
appropriate
22.3.3
Left luggage office
22.3.3.1
General
50-100-150
3
22.3.3.2
Counter
150-200-300
3
Localized lighting is appropriate
22.3.4
Waiting rooms
150-200-300
2
22.3.5
Concourse
150-200-300
2
22.3.6
Time tables
150-200-300
2
Local lighting is appropriate
22.3.7
Loading areas
100-150-200
3
23
GENERAL BUILDING AREAS
23.1
Entrance
23.1.1
Entrance halls, lobbies, waiting rooms
150-200-300
2
23.1.2
Enquiry desks
300-500-750
2
Localized lighting may be appropriate
23.1.3
Gatehouses
150-200-300
2
23.2
Circulation Areas
23.2.1
Lifts
50-100-150
23.2.2
Corridors, passageways, stairs
50-100-150
2
23.23
Escalators, revelators
100-150-200
23.3
Medical and First Aid Centres
23.3.1
Consulting rooms, treatment rooms
300-500-750
1
23.3.2
Rest rooms
100-150-200
1
23.33
Medical stores
100-150-200
2
23.4
Staff Rooms
23.4.1
Changing, locker and cleaners rooms,
cloakrooms, lavatories
50-100-150
23.4.2
Rest rooms
100-150-200
1
23.5
Staff Restaurants
23.5.1
Canteens, cafeterias, dining rooms,
150-200-300
2
mess rooms
23.5.2
Servery, vegetable preparation,
washing-up area
200-300-500
2
23.5.3
Food preparation and cooking
300-500-750
2
23.5.4
Food stores, cellars
100-150-200
2
23.6
Communications
23.6.1
Switchboard rooms
200-300-500
2
23.6.2
Telephone apparatus rooms
100-150-200
2
23.6.3
Telex room, post room
300-500-750
2
23.6.4
Reprographic room
200-300-500
2
23.7
Building Services
23.7.1
Boiler houses
23.7.1.1
Genera]
50-100-150
3
23.7.1.2
Boiler front
100-150-200
3
23.7.1.3
Boiler control room
200-300-500
2
Localized lighting of the control display and
the control desk may be appropriate
23.7.1.4
Control rooms
200-300-500
2
Localized lighting of the control display and
the control desk may be appropriate
23.7.1.5
Mechanical plant room
100-150-200
2
23.7.1.6
Electrical power supply and
distribution rooms
100-150-200
2
23.7.1.7
Store rooms
50-100-150
3
23.8
Car Parks
23.8.1
Covered car parks
23.8.1.1
Floors
5-20
23.8.1.2
Ramps and comers
30
23.8.1.3
Entrances and exits
50-100-150
23.8.1.4
Control booths
150-200-300
23.8.1.5
Outdoor car parks
5-20
NOTE
— For details on use of the ranges of illumination given in
three steps in
this table, reference shall be made to 4.1.4.2,
4.1.4.2.1 and 4.I.4.2.2. For details on quality class of direct glare limitation, reference shall be made to 4.1.3. 1.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
25
4.1.7 For detailed information regarding principles of
good lighting, reference may be made to good practice
[8-1(2)].
4.2 Daylighting
The primary source of lighting for daylighting is the
sun. The light received by the earth from the sun consists
of two parts, namely, direct solar illuminance and sky
illuminance. For the purposes of daylighting design,
direct solar illuminance shall not be considered and
only sky illuminance shall be taken as contributing to
illumination of the building interiors during the day.
4.2.1 The relative amount of sky illuminance depends
on the position of the sun defined by its altitude, which
in turn, varies with the latitude of the locality, the day
of the year and the time of the day, as indicated in
Table 5.
4.2.2 The external available horizontal sky illuminance
(diffuse illuminance) values which are exceeded for
about 90 percent of the daytime working hours may be
taken as outdoor design illuminance values for ensuring
adequacy of daylighting design. The outdoor design
sky illuminance varies for different climatic regions of
the country. The recommended design sky illuminance
values are 6 800 lux for cold climate, 8 000 lux for
composite climate, 9 000 lux for warm humid climate,
9 000 lux for temperate climate and 10 500 lux for hot-
dry climate. For integration with the artificial lighting
during daytime working hours an increase of 500 lux
in the recommended sky design illuminance for
daylighting is suggested.
4.2.3 The daylight factor is dependent on the sky
luminance distribution, which varies with atmospheric
conditions. A clear design sky with its non-uniform
distribution of luminance is adopted for the purposes
of design in this Section.
4.2.4 Components of Daylight Factor
Daylight factor is the sum of all the daylight reaching
on an indoor reference point from the following sources:
a) Direct sky visible from the point,
b) External surfaces reflecting light directly to
the point (see Note 1), and
c) Internal surfaces reflecting and inter-reflecting
light to the point.
NOTES
1 Externa] surface reflection may be computed approximately
only for points at the centre of the room, and for detailed analysis
procedures are complicated and these may be ignored for actual
calculations.
2 Each of the three components, when expressed as a ratio or
percent of the simultaneous external illuminance on the
horizontal plane, defines respectively the sky component (SC),
the external reflected component (ERC) and the internal
reflected component (IRC) of the daylight factor.
4.2.4. 1 The daylight factors on the horizontal plane only
are usually taken, as the working plane in a room is
generally horizontal; however, the factors in vertical
planes should also be considered when specifying
daylighting values for special cases, such as daylighting
on classrooms, blackboards, pictures and paintings hung
on walls.
4.2.5 Sky Component (SC)
Sky component for a window of any size is computed
by the use of the appropriate table of Annex B.
a) The recommended sky component level
should be ensured generally on the working
plane at the following positions:
1) At a distance of 3 m to 3.75 m from the
window along the central line
perpendicular to the window,
2) At the centre of the room if more
appropriate, and
3) At fixed locations, such as school desks,
blackboards and office tables.
b) The daylight area of the prescribed sky
component should not normally be less than
half the total area of the room.
4.2.5. 1 The values obtainable from the tables are for
rectangular, open unglazed windows, with no external
obstructions. The values shall be corrected for the
presence of window bars, glazing and external
obstructions, if any. This assumes the maintenance of
a regular cleaning schedule.
4. 2. 5. 2 Corrections for window bars
The corrections for window bars shall be made by
multiplying the values read from tables in Annex B by
a factor equal to the ratio of the clear opening to the
overall opening.
4. 2. 5.3 Correction for glazing
Where windows are glazed, the sky components
obtained from Annex A shall be reduced by 10 to
20 percent, provided the panes are of clear and clean
glass. Where glass is of the frosted (ground) type, the
sky components read from Annex A may be reduced
by 1 5 to 30 percent. In case of tinted or reflective glass
the reduction is about 50 percent. Higher indicated
correction corresponds to larger windows and/or near
reference points. In the case of openings and glazings
which are not vertical, suitable correction shall be taken
into account.
26
NATIONAL BUILDING CODE OF INDIA 2016
Table 5 Solar Altitudes (to the Nearest Degree) for Indian Latitudes
( Clause 4.2.1)
Period of
Year
22 June
?
I March and 23 September
22 December
Hours of
Day
(Sun or
Solar)
Latitude
07 00
17 00
08 00
16 00
09 00
15 00
10 00
14 00
11 00
13 00
12 00
07 00
17 00
08 00
16 00
09 00
15 00
10 00
14 00
1 1 00
13 00
12 00
07 00
1 7 00
08 00
16 00
09 00
15 00
10 00
14 00
11 00
13 00
12 00
0)
(2)
(3)
(4)
. (5)
(6)
(7)
(8)
(9)
(10)
(H)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
10°N
18
31
45
58
70
77
15
30
44
59
72
80
9
23
35
46
53
57
13°N
19
32
46
60
72
80
15
29
44
58
70
77
8
21
33
43
51
54
16°N
20
33
47
61
74
83
14
29
43
56
68
74
7
19
31
41
48
51
19°N
21
34
48
62
75
86
' 14
28
42
55
66
71
5
18
29
48
45
48
22 °N
22
35
49
62
75
89
14
28
41
53
64
68
4
16
27
36
42
45
25°N
23
36
49
63
76
88
13
27
40
52
61
65
3
14
25
34
39
42
28°N
23
36
49
63
76
86
13
26
39
50
59
62
1
13
23
31
37
39
31°N
24
37
50
62
75
82
13
25
37
48
56
56
—
11
21
28
34
36
34°N
25
37
49
62
73
79
.12
25
36
46
53
56
-
9
18
26
31
33
4.2. 5.4 Correction for external obstructions 4.2.7 Internal Reflected Component (IRC)
There is no separate correction, except that the values
from tables in Annex B shall be read only for the
unobstructed portions of the window.
4.2.6 External Reflected Component (ERC)
The value of the sky component corresponding to the
portion of the window obstructed by the external
obstructions may be found by the use of methods
described in Annex C of good practice [8-1(3)].
These values when multiplied by the correction factors,
corresponding to the mean elevation of obstruction
from the point in question as given in Table 6, can be
taken as the external reflected components for that
point.
Table 6 Correction Factor for ERC
( Clause 4.2.6)
SI No.
(1)
Mean Angle of Elevation
(2)
Correction Factor
(3)
i)
5°
0.086
«)
15°
0.086
iii)
25°
0.142
iv)
35°
0.192
v)
45°
0.226
Vi)
55°
0.274
vii)
65°
0.304
viii)
75°
0.324
ix)
OO
O
0.334
4.2. 6.1 For method of calculating ERC, reference may
be made to accepted standard (see Examples 1 0 and
1 1 given in Annex B of good practice [8-1(3)].
The component of daylight factor contributed by
reflection from the inside surfaces varies directly as
the window area and inversely as the total area of
internal surfaces, and depends on the reflection factor
of the floor, wall and roof surfaces inside and of the
ground outside. For rooms white-washed on walls and
ceiling and windows of normal sizes, the IRC will have
sizeable value even at points far away from the window.
External obstructions, when present, will
proportionately reduce IRC. Where accurate values of
IRC are desired, the same may be done in accordance
with the good practice [8-1(3)].
4.2.8 General Principles of Openings to Afford Good
Lighting
4.2. 8.1 Generally, while taller openings give greater
penetrations, broader openings give better distribution
of light. It is preferable that some area of the sky at an
altitude of 20° to 25° should light up the working plane.
4. 2. 8. 2 Broader openings may also be equally or more
efficient, provided their sills are raised by 300 mm to
600 mm above the working plane.
NOTE — It is to be noted that while placing window with a
high sill level might help natural lighting, this is likely to reduce
ventilation at work levels. While designing the opening for
ventilation also, a compromise may be made by providing the
sill level about 150 mm below the head level of workers.
4. 2. 8.3 For a given penetration, a number of small
openings properly positioned along the same, adjacent
or opposite walls will give better distribution of
illumination than a single large opening. The sky
component at any point, due to a number of openings
may be easily determined from the corresponding sky
PART 8 BUILDING SERVICES — SECTION I LIGHTING AND NATURAL VENTILATION
27
component contour charts appropriately superposed.
The sum of the individual sky component for each
opening at the point gives the overall component due
to all the openings. The same charts may also facilitate
easy drawing of sky component contours due to
multiple openings.
4.2. 8.4 Unilateral lighting from side openings will, in
general, be unsatisfactory if the effective width of the
room is more than 2 to 2.5 times the distance from the
floor to the top of the opening. In such cases provision
of light shelves is always advantageous.
4. 2. 8. 5 Openings on two opposite sides will give
greater uniformity of internal daylight illumination,
especially when the room is 7 m or more across. They
also minimise glare by illuminating the wall
surrounding each of the opposing openings. Side
openings on one side and clerestory openings on the
opposite side may be provided where the situation so
requires.
4.2.8.6 Cross-lighting with openings on adjacent walls
tends to increase the diffused lighting within a room.
4.2.8.7 Openings in deep reveals tend to minimise glare
effects.
4.2. 8. 8 Openings shall be provided with Chajjahs,
louvers, baffles or other shading devices to exclude, as
far as possible, direct sunlight entering the room.
Chajjahs, louvers, etc, reduce the effective height of
the opening for which due allowance shall be made.
Broad and low openings are, in general, much easier
to shade against sunlight entry. Direct sunlight, when
it enters, increases the inside illuminance very
considerably. Glare will result if it falls on walls at low
angles, more so than when it falls on floors, especially
when the floors are dark coloured or less reflective.
4.2.5.9 Light control media, such as translucent glass
panes (opal or matt) surfaced by grinding, etching or
sandblasting, configurated or corrugated glass, certain
types of prismatic glass, tinted glass and glass blasts
are often used. They should be provided, either fixed
or movable outside or inside, especially in the upper
portions of the openings. The lower portions are usually
left clear to afford desirable view. The chief purpose
of such fixtures is to reflect part of the light on to the
roof and thereby increase the diffuse lighting within,
light up the farther areas in the room and thereby
produce a more uniform illumination throughout. They
will also prevent the opening causing serious glare
discomfort to the occupants but will provide some glare
when illuminated by direct sunlight.
4.2.9 Availability of Daylight in Multistoreyed Block
Proper planning and layout of building can add
appreciably to daylighting illumination inside. Certain
dispositions of building masses offer much less mutual
obstruction to daylight than others and have a significant
relevance, especially when intensive site planning is
undertaken. As guidance, the relative availability of
daylight in multi-storeyed blocks (up to 4 storeys) of
different relative orientations may be taken as given in
Table 7.
Table 7 Relative Availability of Daylight on the
Window Plane at Ground Level in a
Four-Storeyed Building Blocks (Clear Design-Sky
as Basis, Daylight Availability Taken as Unity on
an Unobstructed Facade, Values are for the
Centre of the Blocks)
(' Clause 4.2.9)
SI
Distance of
Infinitely
Parallel
Parallel Blocks
No.
Separation
Long
Blocks
facing Gaps
Between
Parallel
Facing Each
Between
Blocks
Blocks
Other
Opposite
(Length -
Blocks
2 x Height)
(Length =
2 x Height)
(1)
(2)
(3)
(4)
(5)
0
0.5 Ht
0.15
0.15
0.25
ii)
1.0 Ht
0.30
0.32
0.38
iii)
1.5 Ht
0.40
0.50
0.55
iv)
2.0 Ht
0.50
0.60
0.68
NOTE — Ht =
Height of building.
4.2.10 For specified requirements for daylighting of
special occupancies and areas, reference may be made
to good practice [8-1(4)].
4.3 Artificial Lighting
4.3.1 Artificial lighting may have to be provided,
a) where the recommended illumination levels
have to be obtained by artificial lighting only;
b) to supplement daylighting when the level of
illumination falls below the recommended
value; and
c) where visual task may demand a higher level
of illumination.
4.3.2 Artificial Lighting Design for Interiors
For general lighting purposes, the recommended
practice is to design for a level of illumination on the
working plane on the basis of the recommended levels
for visual tasks given in Table 4 by a method called
‘Lumen method’. In order to make the necessary
detailed calculations concerning the type and quantity
of lighting equipment necessary, advance information
on the surface reflectances of walls, ceilings and floors
is required. Similarly, calculations concerning the
brightness ratio in the interior call for details of the
interior decoration and furnishing. Stepwise guidance
regarding designing the interior lighting systems for a
28
NATIONAL BUILDING CODE OF INDIA 2016
building using the ‘Lumen method’ is given in 4.3.2. 1
to 4.3. 2. 4.
4.3.2. 1 Determination of the illumination level
Recommended value of illumination shall be taken from
Table 4, depending upon the type of work to be carried
out in the location in question and the visual tasks
involved.
4.3. 2. 2 Selection of the light sources and luminaires
The selection of light sources and luminaires depends
on the choice of lighting system, namely, general
lighting, directional lighting and localized or local
lighting.
4.3. 2.3 Determination of the luminous flux
a) The luminous flux (F) reaching the working
plane depends upon the following:
1 ) Lumen output of the lamps,
2) Type of luminaire,
3) Proportion of the room (room index) (kf
4) Reflectance of internal surfaces of the
room,
5) Depreciation in the lumen output of the
lamps after burning their rated life, and
6) Depreciation due to dirt collection on
luminaires and room surface.
b) Coefficient of utilization or utilization factor
1) The compilation of tables for the
utilization factor requires a considerable
amount of calculations, especially if these
tables have to cover a wide range of
lighting practices. For every luminaire,
the exact light distribution has to be
measured in the laboratory and their
efficiencies have to be calculated and
measured exactly. These measurements
comprise,
i) the luminous flux radiated by the
luminaires directly to the measuring
surface;
ii) the luminous flux reflected and re¬
reflected by the ceiling and the walls
to the measuring surface; and
iii) the inter-reflections between the
ceiling and wall which result in the
measuring surface receiving
additional luminous flux.
All these measurements have to be made
for different reflection factors of the
ceiling and the walls for all necessary
room indices. These tables have also to
indicate the maintenance factor to be
taken for the luminous flux depreciation
throughout the life of an installation due
to ageing of the lamp and owing to the
deposition of dirt on the lamps and
luminaires and room surfaces.
2) The values of the reflection factor of the
ceiling and of the wall are as follows:
White and very light colours : 0.7
Light colours 0.5
Middle tints : 0.3
Dark colours : 0. 1
For the walls, taking into account the
influence of the windows without
curtains, shelves, almirahs and doors with
different colours, etc, should be
estimated.
c) Calculation for determining the luminous flux
[see Table 22 of SP : 41 (S&T) — 1987
‘Handbook on functional requirements of
buildings other than industrial buildings' ]
e
,v A
E ,.A
or, cj) = — — — , for new condition, and
M-
E A
(J) = av~ , for working condition
\i.d
where
<)> = total luminous flux of the light sources
installed in the room, in lumens;
2sav = average illumination level required on the
working plane, in lux;
A = area of the working plane, in m2;
p = utilization factor in new conditions; and
d — maintenance factor.
In practice, it is easier to calculate straightaway the
number of lamps or luminaires from:
^lamp
E* v-A
M4lamp
F 4
N, ■ ■ = av'
luminaires * .
luminaires
where
^lamp
luminous flux of each lamp, in
lumens
^luminaires
luminous flux of each luminaire, in
lumens
■^lamp
total number of lamps
■^luminaires
total number of luminaires.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
29
4.3. 2.4 Arrangement of the luminaires
This is done to achieve better uniformly distributed
illumination. The location of the luminaires has an
important effect on the utilization factor.
a) In general, luminaires are spaced \v’ metre
apart in either direction, while the distance of
the end luminaire from the wall is ‘0.5.r’ metre.
The distance V is more or less equal to the
mounting height 7/m’ between the luminaire
and the working plane. The utilization factor
tables are calculated for this arrangement of
luminaires [see Table 22 of SP : 41 (S&T) -
1987 'Handbook on functional requirements
of buildings other than industrial buildings'],
b) For small rooms where the room index ( k r) is
less than 1, the distance V should always be
less than H, since otherwise luminaires
cannot be properly located. In most cases of
such rooms, four or two luminaires are placed
for good general lighting. If, however, in such
rooms only one luminaire is installed in the
middle, higher utilization factors are obtained,
but the uniformity of distribution is poor. For
such cases, references should be made to the
additional tables for kT = 0.6 to 1.25 for
luminaires located centrally.
4.3.3 Artificial Lighting to Supplement Daylighting
4.3.3. 1 The need for general supplementary artificial
lighting arises due to diminishing of day lighting beyond
design hours, that is. for solar altitude below 1 5° or
when dark cloudy conditions occur.
4. 3.3. 2 The need may also arise for providing artificial
lighting during the day in the innermost parts of the
building which cannot be adequately provided with
daylighting, or when the outside windows are not of
adequate size or when there are unavoidable external
obstructions to the incoming daylighting.
4.3. 3.3 The need for supplementary lighting during
the day arises, particularly when the daylighting on the
working plane falls below 100 lux and the surrounding
luminance drops below 19 cd/m2.
4.3.3.4 The requirement of supplementary artificial
lighting increases with the decrease in daylighting
availability. Therefore, conditions near sunset or sunrise
or equivalent conditions due to clouds or obstructions,
etc, represent the worst conditions when the
supplementary lighting is most needed.
4.3.3. 5 The requirement of supplementary artificial
lighting when daylighting availability becomes poor
may be determined from Fig. 3 for an assumed ceiling
height of 3 .0 m, depending upon floor area, fenestration
percentage and room surface reflectance. Cool daylight
fluorescent tubes are recommended with semi -direct
luminaires. To ensure a good distribution of
illumination, the mounting height should be between
1.5 m and 2.0 m above the work plane for a separation
of 2.0 m to 3.0 m between the luminaires. Also the
number of lamps should preferably be more in the rear
half of the room than in the vicinity' of windows. The
c/3
LLI
CO
=3
t-
h-
Z
UJ
o
C/3
UJ
O'
O
3
o
rt-
UL
o
or
UJ
CO
Z>
z
25 -i
20-
15-
10-
5 -
REFLECTANCE
CEILING
WALLS
FLOOR
0.7
0.7
0.3
—
0.7
0.5
0.3
- — -
0.5
0.5
0.3
OPENINGS,
PERCENT
-10
n - 1 - 1 - r
n - 1 - 1 - r
i i i i
50
150
.2
200
100
FLOOR AREA, m
Fig. 3 Supplementary Artificial Lighting for 40 W Fluorescent Tubes
1 - 1
230
30
NATIONAL BUILDING CODE OF INDIA 2016
following steps may be followed for using Fig. 3 for
determining the number of fluorescent tubes required
for supplementary daylighting.
a) Determine fenestration percentage of the floor
area, that is.
Window area , „
- — — — - x 1 00
Floor area
b) In Fig. 3, refer to the curve corresponding to
the percent fenestration determined above and
the set of reflectances of ceiling, walls and
floor actually provided.
c) For the referred curve of Fig. 3 read, along
the ordinate, the number of 40 W fluorescent
tubes required, corresponding to the given
floor area on the abscissa.
4.3.4 For detailed information on the design aspects
and principles of artificial lighting, reference may be
made to good practice [8-1(2)].
4.3.5 For specific requirements for lighting of special
occupancies and areas, reference may be made to good
practice [8-1(5)].
4.3.6 Electrical installation aspect for artificial lighting
shall be in accordance with Part 8 ‘Building Services,
Section 2 Electrical and Allied Installations’ of the
Code.
4.4 .Energy Conservation in Lighting
4.4.1 A substantial portion of the energy consumed on
lighting may be saved by utilization of daylight and
rational design of supplementary artificial lights.
4.4.2 Daytime use of artificial lights may be minimised
by proper design of windows for adequate daylight
indoors. Daylighting design should be according to 4.2.
4.4.3 Fenestration expressed as percentage of floor area
required for satisfactory visual performance of a few
tasks for different separation to height (S/H) ratio of
external obstructions such as opposite buildings may
be obtained from the design nomogram ( see Fig. 4).
The obstructions at a distance of three times their height
or more ( S/H >3) from a window facade are not
significant and a window facing such an obstruction
may be regarded as a case of unobstructed window.
4.4.3. 1 The nomogram consists of horizontal lines
indicating fenestration percentage of floor area and
vertical lines indicating the separation to height ratio
of external obstructions such as opposite buildings. Any
vertical line for separation to height ratio other than
already shown in the nomogram (1.0, 2.0 and 3.0) may
be drawn by designer, if required. For cases where there
is no obstruction, the ordinate corresponding to the
value 3.0 may be used. The value of percentage
fenestration and separation to height ratio are marked
on left hand ordinate and abscissa, respectively. The
illumination levels are marked on the right hand
ordinate. The values given within brackets are the
illumination levels on the work plane at center and rear
of the room. The wattage of fluorescent tubes required
per nr of the floor area for different illumination levels
is shown on each curve.
4.4.3. 2 Following assumptions have been made in the
construction of the nomogram:
a) An average interior finish with ceiling white,
walls off white and floor grey has been
assumed.
b) Ceiling height of 3 m, room depths up to 10 m
and floor area between 30 m2 and 50 m2 have
been assumed. For floor area beyond 50 m2
and less than 30 m2, the values of percent
fenestration as well as wattage per nr should
be multiplied by a factor of 0.85 and 1.15,
respectively.
c) It is assumed that windows are of metallic
sashes with louvers of width up to 600 mm or
a Chhajja (balcony projection) at ceiling level
of width up to 2.0 m. For wooden sashes, the
window area should be increased by a factor
of about 1.1.
d) Luminaires emanating more light in the
downward direction than upward direction
(such as reflectors with or without diffusing
plastics) and mounted at a height of 1 .5 m to
2.0 m above the work plane have been
considered.
4.4.3. 3 Method of use
The following steps shall be followed for the use of
nomogram:
a) Step l — Decide the desired illumination level
depending upon the task illumination
requirement in the proposed room and read
the value of watts per m2 on the curve
corresponding to the required illumination
level.
b) Step 2 — Fix the vertical line corresponding
to the given separation to height ratio of
opposite buildings on the abscissa. From the
point of intersection of this vertical line and
the above curve move along horizontal, and
read the value of fenestration percent on the
left hand ordinate.
c) Step 3 — If the floor area is greater than 50 m2
or if it is less than 30 m2, the value of watt per
m2 as well as fenestration percent may be
easily determined for adequate daylighting
and supplemental artificial lighting for design
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
31
(360, 200)
200
(320, 175)
175
(280, 150)
150
(240, 125)
125
(200, 100)
100
(150, 75)
75
1.0
2.0
3.0
SEPARATION TO HEIGHT RATIO
Fig. 4 Nomograph for Daylighting and Supplemental Lighting Design of Buildings
32
NATIONAL BUILDING CODE OF INDIA 2016
WORK PLANE ILLUMINATION (LUX) INCLUSIVE OF SUPPLEMENTAL
LIGHTS DURING POOR DAYLIGHT CONDITIONS
purposes. However, if the fenestration
provided is less than the required value, the
wattage of supplementary artificial lights
should be increased proportionately to make
up for the deficiency of natural illumination.
4.4.4 For good distribution of day light on the working
plane in a room, window height, window width and
height of sill should be chosen in accordance with the
following recommendations:
a) In office buildings windows of height 1.2 m
or more in the centre of a bay with sill level at
1.0 to 1.2 m above floor and in residential
buildings windows of height 1.0 m to 1.1 m
with sill height as 0.7 m to 0.9 m above floor
are recommended for good distribution of
daylight indoors. Window width can
accordingly be adjusted depending upon the
required fenestration percentage of the floor
area.
b) If the room depth is more than 10 m, windows
should be provided on opposite sides for
bilateral lighting.
c) It is desirable to have a white finish for ceiling
and off white (light colour) to white for walls.
There is about 7 percent improvement in
lighting levels in changing the finish of walls
from moderate to white.
4.4.5 For good distribution and integration of daylight
with artificial lights the following guidelines are
recommended:
a) Employ cool daylight fluorescent tubes for
supplementary artificial lighting.
b) Distribute luminaries with a separation of 2 m
to 3 m in each bay of 3 m to 4 m width.
c) Provide more supplementary lights such as
twin tube luminaries in work areas where
daylight is expected to be poor, for example
in the rear region of a room having single
window and in the central region of a room
having windows on opposite walls. In the
vicinity of windows only single tube
luminaries should be provided.
4.4.6 Artificial Lighting
Energy conservation in lighting is affected by reducing
wastage and using energy effective lamps and
luminaires without sacrificing lighting quality.
Measures to be followed comprise utilization of
daylight, energy effective artificial lighting design by
providing required illumination where needed, turning
off artificial lights when not needed, maintaining lighter
finishes of ceiling, walls and furnishings, and
implementing periodic schedule for cleaning of
luminaires and group replacement of lamps at suitable
intervals. Choice of light sources with higher luminous
efficacy and luminaires with appropriate light
distribution is the most effective means of energy saving
in lighting. However, choice of light sources also
depends on the other lighting quality parameters like
colour rendering index and colour temperature or
appearance. For example, high pressure sodium vapour
lamps, which have very high luminous efficacy, are not
suitable for commercial interiors because of poor colour
rendering index and colour appearance, but are highly
desirable in heavy industries. Also the choice of light
sources depends on the mounting height in the interiors.
For example, fluorescent lamps are not preferred for
mounting beyond 7 m height, when high pressure gas
discharge lamps are preferred because of better optical
control due to their compact size.
4.4.6. 1 Efficient artificial light sources and luminaires
Luminous efficacies of some of the lamps used in
lighting of buildings are given in Table 8 along with
average life in burning hours, colour rendering index
and colour temperature.
Following recommendations may be followed in the
choice of light sources for different locations:
a) For supplementary artificial lighting of work
area in office building care should be taken to
use fluorescent lamps, which match with
colour temperature of the daylight.
b) For residential buildings fluorescent lamps
and/or CFLs of proper CRI and CCT are
recommended to match with the colours and
interior design of the room.
c) For commercial interiors, depending on the
mounting heights and interior design,
fluorescent lamps, CFLs and low wattage
metal halide lamps are recommended. For
highlighting the displays in show windows,
hotels, etc, low wattage tubular or dichroic
reflector type halogen lamps can be used.
d) For industrial lighting, depending on the
mounting height and colour consideration
fluorescent lamps, high pressure mercury
vapour lamps or high pressure sodium vapour
lamps are recommended.
4. 4. 6. 2 For the same lumen output, it is possible to
save 50 to 70 percent energy if CFL lamps are replaced
with induction lighting, and 40 to 60 percent if replaced
with LED lamps. Similar energy effective solutions are
to be chosen for every application area.
Similarly with white fluorescent tubes recommended
for corridors and staircases, the electrical consumption
reduces to 1/4.5 of the energy consumption with
incandescent lamps.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
33
Table 8 Luminous Efficacy, Life, Lumen Maintenance and Colour Rendition of Light Sources
(Clause 4.4.6. 1 )
SI
Light Source
Wattage
Efficacy
Average Life
Lumen
Colour Rendition
No.
Range
VV
Im \V
h
Maintenance
(1)
(2)
(3)
(4)
(5)
(6)
(7)
i)
Incandescent lamps
15 to 200
12 to 20
500 to 1 000
Fair to good
Very good
ii)
Tungsten halogen
300 to 1 500
20 to 27
200 to 2 000
Good to very good
Very good
iii)
Standard fluorescent lamps
20 to SO
55 to 65
5 000
Fair to good
Good
iv)
Compact fluorescent lamps (CFL)
5 to 40
60 to 70
7 500
Good
Good to very good
v)
Slim line fluorescent
18 to 58
57 to 67
5 000
Fair to good
Good
V)
High pressure mercury vapour lamps
60 to 1 000
50 to 65
5 000
Very low to fair
Federate
vi)
Blended - light lamps
160 to 250
20 to 30
5 000
Low to fair
Federate
vii)
High pressure sodium vapour lamps
50 to 1 000
90 to 125
10 000 to 15 000
Fair to good
Low to good
viii)
Metal halide lamps
35 to 2 000
80 to 95
4 000 to 10 000
Very low
Very good
ix)
Low pressure sodium
10 to 180
100 to 200
10 000 to 20 000
Good to very good
Poor
x)
LED
0.5 to 2.0
60 to 100
10 000
Very good
Good for white LED
NOTES
1 The table includes lamps and wattages currently in use in buildings in India.
2 Luminous efficacy varies with the wattage of the lamp.
3 Average life values are from available Indian Standards. Where Indian Standard is not available, values given are only indicative.
4 For exact values, it is advisable to contact manufacturers.
4.4.6.3 Efficient luminaire also plays an important role
for energy conservation in lighting. The choice of a
luminaire should be such that it is efficient not only
initially but also throughout its life. Following
luminaries are recommended for different locations:
a) For offices semi-direct type of luminaries are
recommended so that both the work plane
illumination and surround luminance can be
effectively enhanced.
b) For corridors and stair cases direct type of
luminaries with wide spread of light
distributions are recommended.
c) In residential buildings, bare fluorescent tubes
are recommended. Wherever the incandescent
lamps are employed, they should be provided
with white enameled conical reflectors at an
inclination of about 45° from vertical.
4.4.7 Cleaning Schedule for Window Panes and
Luminaires
Adequate schedule for cleaning of window panes and
luminaries will result in significant advantage of
enhanced daylight and lumen output from luminaries.
This will tend to reduce the duration over which
artificial lights will be used and minimise the wastage
of energy. Depending upon the location of the building
a minimum of three to six months interval for periodic
cleaning of luminaries and window panes is
recommended for maximum utilization of daylight and
artificial lights.
4.4.8 Photocontrols for Artificial Lights
There is a considerable wastage of electrical energy in
lighting of buildings due to carelessness in switching
off lights even when sufficient daylight is available
indoors. In offices and commercial buildings, occupants
may switch on lights in the morning and keep them on
throughout the day. When sufficient daylight is
available inside, suitable photo controls can be
employed to switch off the artificial lights and thus
prevent the wastage of energy.
The photocontrol should have the following features:
a) An integrated photocontrol system continually
measures the amount of visible light under the
lighting fixture and maintains the lux levels
as referred in Table 4.
b) An integrated photocontrol system should
maintain six daylighting scenarios that can be
adjusted by the user namely; daytime
occupied, daytime unoccupied, sunset
occupied, sunset unoccupied, night time
occupied and night time unoccupied.
c) The photocontrol sensor should have
a 60° cone of reference to measure the amount
of light on the work surface.
34
NATIONAL BUILDING CODE OF INDIA 2016
4.4.9 Solar Photovoltaic Systems (SPV)
Solar photovoltaic system enables direct conversion of
sunlight into electricity and is a \ iable option for
lighting purpose in remote nongrid areas. The common
SPV lighting systems are:
a) Solar lantern.
b) Fixed type solar home lighting system, and
c) Street lighting system.
4.4.9. 1 SPV lighting system should preferably be
provided with CFL for energy efficiency.
4. 4. 9. 2 Inverters used in buildings for supplying
electricity during the power cut period should be
charged through SPV system.
4. 4. 9. 3 Regular maintenance of SPV system is
necessary for its satisfactory functioning.
4.4.10 Lighting shelves and light pipes may be explored
for utilization and integration in the lighting design.
5 VENTILATION
5.1 General
Ventilation of buildings is required to supply fresh air
for respiration of occupants, to dilute inside air to
prevent vitiation by body odours and to remove any
products of combustion or other contaminants in air
and to provide such thermal environments as will assist
in the maintenance of heat balance of the body in order
to prevent discomfort and injury to health of the
occupants.
5.2 Design Considerations
5.2.1 Respiration
Supply of fresh air to provide oxygen for the human
body for elimination of waste products and to maintain
carbon dioxide concentration in the air within safe limits
rarely calls for special attention as enough outside air
for this purpose normally enters the areas of occupancy
through crevices and other openings.
5.2. 1.1 In normal habitable rooms devoid of smoke
generating source, the content of carbon dioxide in air
rarely exceeds 0.5 percent to 1 percent and is. therefore,
incapable of producing any ill effect. The amount of
air required to keep the concentration down to 1 percent
is very small. The change in oxygen content is also too
small under normal conditions to have any ill effects;
the oxygen content may vary quite appreciably without
noticeable effect, if the carbon dioxide concentration
is unchanged.
5.2.2 Vitiation by Body Odours
Where no products of combustion or other
contaminants are to be removed from air, the amount
of fresh air required for dilution of inside air to prevent
\ iliation of air by body odours, depends on the air space
available per person and the degree of physical activity;
the amount of air decreases as the air space available
per person increases, and it may vary from 20 nr' to
30 m3 per person per hour. In rooms occupied by only
a small number of persons such an air change will
automatically be attained in cool weather by norma!
leakage around windows and other openings and this
may easily be secured in wann weather by keeping the
openings open.
No standards have been laid down under Factories Act,
1948 as regards the amount of fresh air required per
worker or the number of air changes per hour. Section
16 of the Factories Act, 1948 relating to overcrowding
requires that at least 14 m3 to 16 m3 of space shall be
provided for every worker and for the purpose of that
section no account shall be taken of any space in a work
room which is more than 4.25 m above the floor level.
NOTE — Vitiation of the atmosphere can also occur in factories
by odours given off due to contaminants of the product itself,
say for example, from tobacco processing in a ‘ Beedi ' factory.
Here the ventilation will have to be augmented to keep odours
within unobjectionable levels.
5.2.2. 1 Recommended values for air changes
The standards of general ventilation are recommended/
based on maintenance of required oxygen, carbon
dioxide and other air quality levels and for the control
of body odours when no products of combustion or
other contaminants are present in the air; the values of
air changes should be as follows:
SI No.
(1)
Application
(2)
Air Change per Hour
(3)
1.
Assembly rooms
4-8
2.
Bakeries
20-30
3.
Banks/building societies
4-8
4.
Bathrooms
6-10
5.
Bedrooms
2-4
6.
Billiard rooms
6-8
7.
Boiler rooms
see Note 2
8.
Cafes and coffee bars
10-12
9.
Canteens
8-12
10.
Cellars
3-10
11.
Changing rooms
6-10
12.
Churches
1-3
13.
Cinemas and theatres
10-15
14.
Club rooms
12, Min
15.
Compressor rooms
10-12
16.
Conference rooms
8-12
17.
Corridors
5-10
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
35
SI No. Application Air Change per Hour
(1) (2) (3)
18. Dairies
8-12
19. Dance halls
12, Min
20. Dye works
20-30
2 1 . Electroplating shops
10-12
22. Engine rooms/DG
see Note 2
Rooms/GG Rooms
23. Entrance halls
3-5
24. Factories and work shops
8-10
25. Foundries
15-30
26. Garages
6-8
27. Glass houses
25-60
28. Gymnasium
6, Min
29. Hair dressing saloon
10-15
30. Hospitals sterilising
15-25
3 1 . Hospital wards
6-8
32. Hospital domestic
15-20
33. Laboratories
6-15
34. Launderettes
10-15
35. Laundries
10-30
36. Lavatories
6-15
37. Lecture theatres
5-8
38. Libraries
3-5
39. Lift cars
20, Min
40. Living rooms
3-6
4 1 . Mushroom houses
6-10
42. Offices
6-10
43. Paint shops (not cellulose)
10-20
44. Photo and X-ray dark room
10-15
45. Public house bars
12, Min
46. Recording control rooms
15-25
47. Recording studios
10-12
48. Restaurants
8-12
49. Schoolrooms
5-7
50. Shops and supermarkets
8-15
5 1 . Shower baths
15-20
52. Stores and warehouses
3-6
53. STP rooms
30, Min
54. Squash courts
4, Min
5 5 . Swimming baths
10-15
56. Toilets
6-10
57. Underground vehicle parking
6, Min
58. Utility rooms
15-30
59. Welding shops
15-30
NOTES
1 The ventilation rates may be increased by 50 percent where
heavy smoking occurs or if the room is below the ground.
2 The ventilation rate shall be as per 11.2.2 of Part 8 ‘Building
Services, Section 3 Air Conditioning, Heating and Mechanical
Ventilation’ of the Code.
5.2.3 Heat Balance of Body
Especially in hot weather, when thermal environment
inside the room is worsened by heat given off by
machinery, occupants and other sources, the prime need
for ventilation is to provide such thermal environment
as will assist in the maintenance of heat balance of the
body in order to prevent discomfort and injury to health.
Excess of heat either from increased metabolism due
to physical activity of persons or gains from a hot
environment has to be offset to maintain normal body
temperature (37 °C). Heat exchange of the human body
with respect to the surroundings is determined by the
temperature and humidity gradient between the skin
and the surroundings and other factors, such as age of
persons, clothing, etc, and the latter depends on air
temperature (dry bulb temperature), relative humidity,
radiation from the solid surroundings and rate of air
movement. The volume of outside air to be circulated
through the room is, therefore, governed by the physical
considerations of controlling the temperature, air
distribution or air movement. Air movement and air
distribution may, however, be achieved by recirculation
of the inside air rather than bringing in all outside air.
However, fresh air supply or the circulated air will
reduce heat stress by dissipating heat from body by
evaporation of the sweat, particularly when the relative
humidity is high and the air temperature is near body
temperature.
5.2.3. 1 Indices of thermal comfort
Thermal comfort is that condition of thermal
environment under which a person can maintain a body
heat balance at normal body temperature and without
perceptible sweating. Limits of comfort vary
considerably according to studies carried out in India
and abroad.
The thermal indices which find applications for Indian
climate are as follows:
a) Effective temperature (ET),
b) Tropical summer index (TSI), and
c) Adaptive thermal comfort.
5.2.3. 1.1 Effective temperature (ET)
Effective temperature is defined as the temperature of
still, saturated air which has the same general effect
upon comfort as the atmosphere under investigation.
Combinations of temperature, humidity and wind
velocity producing the same thennal sensation in an
individual are taken to have the same effective
temperature.
Initially two scales were developed, one of which
referred to men stripped to the waist, and called the
basic scale. The other applies to men fully clad in indoor
clothing and called the normal scale of effective
36
NATIONAL BUILDING CODE OF INDIA 2016
temperature. Bedfort ( 1 946) proposed the use of globe
temperature reading instead of the air temperature
reading to make allowance for the radiant heat. This
scale is known as the corrected effective temperature
(CET) scale. No allowance, however, was made for
the different rates of energy expenditure. The scale was
compiled only for men either seated or engaged in light
activity.
Figure 5 represents the corrected effective temperature
nomogram. The CET can be obtained by connecting
the appropriate points representing the dry bulb (or
globe) and wet bulb temperatures and reading the CET
value at the intersection of this line with the relevant
air velocity curve from the family of curves for various
air velocities running diagonally upwards from left to
right.
The effective temperature scale may be considered to
be reasonably accurate in warm climates where the heat
stress is not high but it may be misleading at high levels
of heat stress. There appears to be an inherent error in
this scale if used as an index of physiological strain,
the error increasing with the severity of the
environmental conditions. For low and moderate
degrees of heat stress, the effective temperature scales
appear to assess climatic heat stress with an accuracy
which is acceptable for most practical purposes.
5.2.3. 1.2 Tropical summer index (TS1)
The TSI is defined as the temperature of calm air,
at 50 percent relative humidity which imparts the same
thermal sensation as the given environment. The
50 percent level of relative humidity is chosen for this
index as it is a reasonable intermediate value for the
prevailing humidity conditions. Mathematically, TSI
(°C) is expressed as:
TSI = 0.745/g + 0.308rw -2.06^v + 0.841
where
/w = wet bulb temperature, in °C;
/ = globe temperature, in °C; and
V = air speed, in m/s.
The thermal comfort of a person lies between TSI
values of 25°C and 30°C with optimum condition at
27.5°C. Air movement is necessary in hot and humid
weather for body cooling. A certain minimum desirable
wind speed is needed for achieving thermal comfort at
different temperatures and relative humidities. Such
0 5 10 15 20 25 30 35 40 45
Wet bulb temperature °C
Fig. 5 Corrected Effective Temperature Nomogram
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
37
wind speeds are given in Table 9. These are applicable
to sedentary work in offices and other places having
no noticeable sources of heat gain. Where somew hat
warmer conditions are prevalent, such as in godowns
and machine shops and work is of lighter intensity, and
higher temperatures can be tolerated without much
discomfort, minimum wind speeds for just acceptable
warm conditions are given in Table 10. For obtaining
values of indoor wind speed above 2.0 m/s, mechanical
means of ventilation may have to be adopted (see also
Part 8 ‘Building Services, Section 3 Air Conditioning,
Heating and Mechanical Ventilation’ of the Code).
The warmth of the environment was found tolerable
between 30°C and 34°C (TSJ), and too hot above this
limit. On the lower side, the coolness of the environment
w'as found tolerable between 19°C and 25°C (TSI) and
below 19°C (TSI), it was found too cold.
Table 9 Desirable Wind Speeds (m/s) for
Thermal Comfort Conditions
(Clause 5. 2.3. 1.2)
SI.
Dry Bulb
Relative Humidity
No.
Temperature
Percent
°C
30
40
50
60
70
80
90
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
i)
28
i)
i)
1)
i)
i)
1)
i)
ii)
29
i)
i)
i)
i)
i)
0.06
0.19
Hi)
30
i)
i)
0
0.06
0.24
0.53
0.85
iv)
31
i)
0.06
0.24
0.53
1.04
1.47
2.10
v)
32
0.20
0.46
0.94
1.59
2.26
3.04
2)
vi)
33
0.77
1.36
2.12
3.00
2)
2)
2)
vii)
34
1.85
2.72
2)
2)
2)
2)
2)
viii)
35
3.20
2)
2)
2)
2)
2)
2)
1) None.
2) Higher than those acceptable in practice.
Table 10 Minimum Wind Speeds (m/s) for Just
Acceptable Warm Conditions
(Clause 5.2.3. 1.2)
SI
No.
(1)
Dry Bulb
Temperature
X
(2)
Relative Humidity
Percent
30
(3)
40
(4)
50
(5)
60
(6)
70
(7)
80
(8)
90
(9)
i)
2S
1)
0
ii
n
0
i)
1)
i>)
29
1)
1)
1)
i)
i)
1)
1)
iii)
30
i)
1)
1)
i)
1)
i)
n
iv)
31
1)
i)
1)
n
i)
0.06
0.23
v)
32
1)
1)
! J
0.09
0.29
0.60
0.94
vi)
33
D
0.04
0.24
0.60
1.04
1.85
2.10
vii)
34
0.15
0.46
0.94
1.60
2.26
3.05
2)
viii)
35
0.68
1.36
2.10
3.05
2)
2)
2)
ix)
36
1.72
2.70
2)
2)
2)
2)
2)
l) None.
21 Higher than those acceptable in practice.
5. 2. 3. 1.3 Adaptive thermal comfort
For details on adaptive thermal comfort, reference shall
be made to Part S ‘Building Sen ices. Section 3 Air
Conditioning. Heating and Mechanical Ventilation’ of
this Code.
5.2.3. 2 There will be a limit of heat tolerance w hen air
temperatures are excessive and the degree of physical
activity is high. This limit is determined when the bodily
heat balance is upset, that is, when the bodily heat gain
due to conduction, convection and the radiation from
the surroundings exceeds the bodily heat loss, which is
mostly by evaporation of sweat from the surface of the
body. The limits of heat tolerance for Indian workers
are based on the study conducted by the Chief Adviser
Factories, Government of India, Ministry of Labour
and are given in his report on Thermal Stress in Textile
Industry (Report No. 1 7) issued in 1 956. According to
this Report, where workers in industrial buildings
wearing light clothing are expected to do work of
moderate severity with the energy expenditure in the
range 273 to 284 W, the maximum wet bulb temperature
shall not exceed 29°C and adequate air movement
subject to a minimum air velocity of 30 m/min shall be
provided, and in relation to the dry bulb temperature,
the wet bulb temperature of air in the work room, as
far as practicable, shall not exceed that given in
Table 11.
Table 11 Maximum Permissible Wet Bulb
Temperatures for Given Dry Bulb Temperatures
(Clause 5. 2. 3.2)
SI
Dry Bulb
Maximum Wet-Bulb
No.
Temperature
Temperature
°C
°C
(1)
(2)
(3)
i)
30
29.0
ii)
35
28.5
iii)
40
28.0
iv)
45
27.5
v)
50
27.0
NOTES
1 These are limits beyond which the industry should not allow
the thermal conditions to go for more than lh continuously.
The limits are based on a series of studies conducted on Indian
subjects in psychrometric chamber and on other data on heat
casualties in earlier studies conducted in Kolar Gold Fields and
elsewhere.
2 Figures given in this table are not intended to convey that
human efficiency at SCFC will remain the same as at 30°C,
provided appropriate wet bulb temperatures are maintained.
Efficiency decreases with rise in the dry bulb temperature as
well, as much as possible. Long exposures to temperature of
50°C dry bulb/27°C wet bulb may prove dangerous.
3 Refrigeration or some other method of cooling is
recommended in all cases where conditions would be worse
than those shown in this table.
38
NATIONAL BUILDING CODE OF INDIA 2016
5.3 Methods of Ventilation
General ventilation involves providing a building with
relatively large quantities of outside air in order to
improve general env ironment of the building. This may
be achieved in one of the following ways:
a) Natural supply and natural exhaust of air;
b) Natural supply and mechanical exhaust of air;
c) Mechanical supply and natural exhaust of air:
and
d) Mechanical supply and mechanical exhaust of
air.
5.3.1 Control of Heat
Although it is recognized that general ventilation is one
of the most effective methods of improving -thermal
environmental conditions in factories, in many
situations, the application of ventilation should be
preceded by and considered along with some of the
following other methods of control. This would
facilitate better design of buildings for general
ventilation, either natural or mechanical or both, and
also reduce their cost.
5.3. 1.1 Isolation
Sometimes it is possible to locate heat producing
equipment, such as furnaces in such a position as would
expose only a small number of workers to hot
environment. As far as practicable, such sources of heat
in factories should be isolated.
In situations where relatively few people are exposed
to severe heat stress and their activities are confined to
limited areas as in the case of rolling mill operators
and crane operators, it may be possible to enclose the
work areas and provide spot cooling or supply
conditioned air to such enclosures.
5.3. 1.2 Insulation
A considerable portion of heat in many factories is due
to the solar radiation falling on the roof surfaces, which,
in turn, radiate heat inside the building. In such
situations, insulations of the roof or providing a false
ceiling or double roofing would be very effective in
controlling heat. Some reduction can also be achieved
by painting the roof in heat reflective shades.
Hot surfaces of equipment, such as pipes, vessels, etc,
in the building should also be insulated to reduce their
surface temperature.
5.3. 1.3 Substitution
Sometimes, it is possible to substitute a hot process by
a method that involves application of localized or more
efficiently controlled method of heating. Examples
include induction hardening instead of conventional
heat treatment, cold riveting or spot welding instead of
hot riveting, etc.
5. 3. 1.4 Radiant shielding
Hot surfaces, such as layers of molten metal emanate
radiant heat, which can best be controlled by placing a
shield having a highly reflecting surface between the
source of heat and the worker, so that a major portion
of the heat falling on the shield is reflected back to the
source. Surfaces such as of tin and aluminium have
been used as materials for shields. The efficiency of
the shield does not depend on its thickness, but on the
reflectivity and emissivity of its surface. Care should
be taken to see that the shield is not heated up by
conduction and for this purpose adequate provision
should be made for the free flow upwards of the heated
air between the hot surface and the shield by leaving
the necessary air space and providing opening at the
top and the bottom of the sides.
5.3.2 Volume of Air Required
The volume of air required shall be calculated by using
both the sensible heat and latent heat gain as the bases.
The larger of the two values obtained should be used
in actual practice.
In places without sufficient wind speeds and/or in
buildings where effective cross ventilation is not
possible due to the design of the interior, the indoor air
may be exhausted by a fan, with outdoor air entering
the building through the open windows.
5.3.2. 1 Volume of air required for removing sensible
heat
When the amount of sensible heat given off by different
sources, namely, the sun, the manufacturing processes,
machinery', occupants and other sources, is known and
a suitable value for the allowable temperature rise is
assumed, the volume of outside air to be provided for
removing the sensible heat may be calculated from:
^ 2.976 8 K .
= 7
where
Oj = quantity of air, in m Vh;
Ks - sensible heat gained, in W; and
r = allowable temperature rise, in °C.
5.3. 2. 2 Temperature rise refers mainly to the difference
between the air temperatures at the outlet (roof exit)
and at the inlet openings for outside air. As very little
inlet data exist on allowable temperature rise values
for supply of outside air in summer months, the values
given in Table 12 related to industrial buildings may
be used for general guidance.
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
39
Table 12 Allowable Temperature Rise Values
(' Clause 5. 3. 2. 2)
SI No. Height of Outlet Opening Temperature Rise
m °C
(1) (2) (3)
0 6 3 to 4.5
ii) 9 4.5 to 6.5
iii) 12 6.5 to 11
NOTES
1 The conditions are limited to light or medium heavy
manufacturing processes, freedom from radiant heat and inlet
openings not more than 3 to 4.5 m above floor level.
2 At the working zone between floor level and 1.5 m above
floor level, the recommended maximum allowable temperature
rise for air is 2°C to 3°C above the air temperature at the inlet
openings.
5.3.2.3 Volume of air required for removing latent heat
If the latent heat gained from the manufacturing
processes and occupants is also known and a suitable
value for the allowable rise in the vapour pressure is
assumed:
^ _ 4 127.26 ATj
ft- -
where
ft = quantity of air, in m3/h;
Kx = latent heat gained, in W; and
h = allowable vapour pressure difference of
mercury, in mm.
NOTE — In majority of the cases, the sensible heat gain will
far exceed the latent heat gain, so that the amount of outside
air to be drawn by ventilating equipment can be calculated in
most cases on the basis of the equation given in 5.3.2.I.
5.3.2.4 Ventilation is also expressed as m3/h/m2 of floor
area. This relationship fails to evaluate the actual heat
relief provided by a ventilation system, but it does give
a relationship which is independent of building height.
This is a more rational approach, because, with the same
internal load, the same amount of ventilation air,
properly applied to the work zone with adequate
velocity, will provide the desired heat relief quite
independently of the ceiling height of the space, with
few exceptions. Ventilation rates of 30 to 60 m3/h/m2
have been found to give good results in many plants.
5.4 Natural Ventilation
The rate of ventilation by natural means through
windows or other openings depends on,
a) direction and velocity of wind outside and
sizes and disposition of openings (wind
action); and
b) convection effects arising from temperature
of vapour pressure difference (or both)
between inside and outside the room and the
difference of height between the outlet and
inlet openings (stack effect).
5.4.1 Ventilation of Non-Industrial Buildings
Ventilation in non-industrial buildings due to stack
effect, unless there is a significant internal load, could
be neglected, except in cold regions, and wind action
may be assumed to be predominant.
5.4.1. 1 In hot dry regions, the main problem in summer
is to provide protection from sun’s heat so as to keep
the indoor temperature lower than those outside under
the sun. For this purpose windows and other openings
are generally kept closed during day time and only
minimum ventilation is provided for the control of
odours or for removal of products of combustion.
5.4. 1.2 In warm humid regions, the problem in the
design of non-industrial buildings is to provide free
passage of air to keep the indoor temperature as near
to those outside in the shade as possible, and for this
purpose the buildings are oriented to face the direction
of prevailing winds and windows and other openings
are kept open on both windward and leeward sides.
5.4. 1.3 In winter months in cold regions, the windows
and other openings are generally kept shut, particularly
during night; and ventilation necessary for the control
of odours and for the removal of products of combustion
can be achieved either by stack action or by some
infiltration of outside air due to wind action.
5.4.2 Ventilation of Industrial Buildings
In providing natural ventilation of all industrial
buildings having significant internal heat loads due to
manufacturing process, proper consideration should be
given to the size and distribution of windows and other
inlet openings in relation to outlet openings so as to
give, with due regard to orientation, prevailing winds,
size and configuration of the building and
manufacturing processes carried on, maximum possible
control of thermal environment.
5.4.2. 1 In the case of industrial buildings wider than
30 m, the ventilation through windows may be
augmented by roof ventilation.
5.4.3 Design Guidelines for Natural Ventilation
5.4.3. 1 By wind action
1) A building need not necessarily be oriented
perpendicular to the prevailing outdoor wind;
it may be oriented at any convenient angle
between 0° and 30° without losing any
beneficial aspect of the breeze. If the
prevailing wind is from East or West, building
may be oriented at 45° to the incident wind so
40
NATIONAL BUILDING CODE OF INDIA 2016
as to diminish the solar heat without much
reduction in air motion indoors.
2) Inlet openings in the buildings should be well
distributed and should be located on the
windward side at a low level, and outlet
openings should be located on the leeward
side. Inlet and outlet openings at high levels
may only clear the top air at that level without
producing air movement at the level of
occupancy.
3) Maximum air movement at a particular plane
is achieved by keeping the sill height of the
opening at 85 percent of the critical height
(such as head level) for the following
recommended levels of occupancy:
a) For sitting on chair 0.75 m,
b) For sitting on bed 0.60 m, and
c) For sitting on floor 0.40 m.
4) Inlet openings should not as far as possible
be obstructed by adjoining buildings, trees,
sign boards or other obstructions or by
partitions inside in the path of air flow.
5) In rooms of normal size having identical
windows on opposite walls the average indoor
air speed increases rapidly by increasing the
width of window up to two-third of the wall
width; beyond that the increase is in much
smaller proportion than the increase of the
window width. The air motion in the working
zone is maximum when window height is
1.1m. Further increase in window height
promotes air motion at higher level of window,
but does not contribute additional benefits as
regards air motion in the occupancy zones in
buildings.
6) Greatest flow per unit area of openings is
obtained by using inlet and outlet openings of
nearby equal areas at the same level.
Fig. 6 Effect of Area of Opening on Average
Indoor Wind Velocity
7) For a total area of openings (inlet and outlet)
of 20 percent to 30 percent of floor area, the
average indoor wind velocity is around
30 percent of outdoor velocity. Further
increase in window size increases the available
velocity but not in the same proportion as
shown in Fig. 6. In fact, even under most
favourable conditions the maximum average
indoor wind speed does not exceed 40 percent
of outdoor velocity.
8) Where the direction of wind is quite constant
and dependable, the size of the inlet should
be kept within 30 to 50 percent of the total
area of openings and the building should be
oriented perpendicular to the incident wind.
Where direction of the wind is quite variable
the openings may be arranged so that as far as
possible there is approximately equal area on
all sides. Thus no matter what the wind
direction be, there would be some openings
directly exposed to wind pressure and others
to air suction and effective air movement
through the building would be assured.
9) Windows of living rooms should open directly
to an open space. In places where building
sites are restricted, open space may have to
be created in the buildings by providing
adequate courtyards.
10) In the case of rooms with or^ly one wall
exposed to outside, provision of two windows
on that wall is preferred to that of a single
window.
11) Windows located diagonally opposite to each
other with the windward window near the
upstream comer give better performance than
other window arrangements for most of the
building orientations.
12) Horizontal louvers, that is, sunshades atop
windows deflect the incident wind upward and
reduce air motion in the zone of occupancy. A
horizontal slot between the wall and horizontal
louver prevents upward deflection of air in the
interior of rooms. Provision of inverted L type
(r) louver increases the room air motion
provided that the vertical projection does not
obstruct the incident wind {see Fig. 7).
13) Provision of horizontal sashes inclined at an
angle of 45° in appropriate direction helps to
promote the indoor air motion. Sashes
projecting outward are more effective than
projecting inward.
14) Air motion at working plane 0.4 m above the
floor can be enhanced by 30 percent using a
pelmet type wind deflector {see Fig. 8).
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
41
Fig. 7 L-Type Louver
1 5) Roof overhangs help promoting air motion in
the working zone inside buildings.
16) In case of room with windows on one wall,
with single window, the room wind velocity
inside the room on the windward side is
10 percent of outdoor velocity at points up to
a distance of one-sixth of room width from the
window and then decreases rapidly and hardly
any air movement is produced in the leeward
half portion of the room. The average indoor
wind velocity is generally less than 1 0 percent
of outdoor velocity'. When two windows are
provided and wind impinges obliquely on
them, the inside velocity increases up to
15 percent of the outdoor velocity.
Fig. 8 Sketch of a Pelmet Ty
17) C ross ventilation can be obtained through one
side of the building to the other, in case of
narrow buildings with the width common in
the multislorey'ed type by the provision of
large and suitably placed windows or
combination of windows and wall ventilators
tor the inflow and outflow of air.
1 8) Verandah open on three sides is to be preferred
since it causes an increase in the room air
motion for most of the orientations of the
building with respect to the outdoor wind.
1 9) A partition placed parallel to the incident wind
has little influence on the pattern of the air
flow, but when located perpendicular to the
main flow, the same partition creates a wind
shadow. Provision of a partition with spacing
of 0.3 m underneath helps augmenting air
motion near floor level in the leeward
compartment of wide span buildings.
20) Air motion in a building unit having windows
tangential to the incident wind is accelerated
when another unit is located at end-on position
on downstream side (see Fig. 9).
21) Air motion in two wings oriented parallel to
the prevailing breeze is promoted by connecting
them with a block on downstream side.
Hw- WINDOW HEIGHT
HD- DEFLECTOR HEIGHT
WD - DEFLECTOR WIDTH
Wind Deflector
NATIONAL BUILDING CODE OF INDIA 2016
1 1
tf j
/
7 II HI
hi
//
' / / / / ii
Fig. 9 Two Units Located at the End-on Position
22) Air motion in a building is not affected by
constructing another building of equal or
smaller height on the leeward side; but it is
slightly reduced if the leeward building is
taller than the windward block.
23) Air motion in a shielded building is less than
that in an unobstructed building. To minimise
shielding effect, the distances between two
rows should be 8 H for semi-detached houses
and 10 //for long rows houses. However, for
smaller spacing the shielding effect is also
diminished by raising the height of the
shielded building.
24) Hedges and shrubs defect the air away from
the inlet openings and cause a reduction in
indoor air motion. These elements should not
be planted at a distance of about 8 m from the
building because the induced air motion is
reduced to minimum in that case. However,
air motion in the leeward part of the building
can be enhanced by planting a low hedge at a
distance of 2 m from the building.
25) Trees with large foliage mass having trunk
bare of branches up to the top level of window,
deflect the outdoor wind downwards and
promotes air motion in the leeward portion of
buildings,
26) Ventilation conditions indoors can be
ameliorated by constructing buildings on earth
mound having a slant surface with a slope of
1 0° on upstream side.
27) In case of industrial buildings the window
height should be about 1 .6 m and width about
two-ihird of wall width. These should be
located at a height of 1.1 m above the floor.
In addition to this, openings around 0.9 m high
should be provided over two-third length of
the glazed area in the roof iights.
28) Height of industrial buildings, although
determined by the requirements of industrial
processes involved, generally kept large
enough to protect the workers against hot
stagnant air below the ceiling as also to dilute
the concentration of contaminant inside.
However, if high level openings in roof or
walls are provided, building height can be
reduced to 4 m without in any way impairing
the ventilation performance.
29) The maximum width up to which buildings of
height usually found in factories, being
effectively ventilated by natural means by
wind action, is 30 m, beyond which sufficient
reliance cannot be placed on prevailing winds.
Approximately half the ventilating area of
openings should be between floor level and a
height of 2.25 m from the floor.
NOTE — For data on outdoor wind speeds at a place, reference
may be made to ‘The Climatic Data Handbook’ prepared by
Central Building Research Institute, Roorkee, 1999’.
5.4.3.2 By stack effect
Natural ventilation by stack effect occurs when air
inside a building is at a different temperature than air
outside Thus in heated buildings or in buildings
wherein hot processes are carried on and in ordinary
buildings during summer nights and during pre¬
monsoon periods, the inside temperature is higher than
that of outside, cool outside air will tend to enter through
openings at low level and warm air will tend to leave
through openings at high level. It would, therefore, be
advantageous to provide ventilators as close to ceilings
as possible. Ventilators can also be provided in roofs
as, for example, cowl, vent pipe, covered roof and ridge
vent.
5.5 Mechanical Ventilation
The requirements of mechanical ventilation shall be in
accordance with Part 8 ‘Building Services, Section 3
Air Conditioning, Heating and Mechanical Ventilation’
of the Code.
5.6 Determining Rate of Ventilation
5.6J Natural Ventilation
This is difficult to measure as it varies from time to
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
43
time. The amount of outside air through windows and
other openings depends on the direction and velocity
of wind outside (wind action) and/or convection effects
arising from temperature or vapour pressure differences
(or both) between inside and outside of the building
(stack effect).
5. 6. 1.1 Wind action
For determining the rate of ventilation based on wind
action the wind may be assumed to come from any
direction within 45° of the direction of prevailing wind.
Ventilation due to external wind is given by the
following formula:
Q,=K.A.v
resulting air flow is not equal to the two flows estimated
separately.
When acting simultaneously, the rate of air flow through
the building may be computed by the following
equation:
g2=ew2+a2
where
Q = resultant volume of air flow, in m3/min;
Qw = volume of air flow due to wind force, in m3/
min; and
Qt = volume of air flow due to thermal force, in
m3/min.
where
Qw = rate of air flow, in m3/h;
K = coefficient of effectiveness, which may be
taken as 0.6 for wind perpendicular to
openings and 0.3 for wind at an angle less
than 45° to the openings;
A = free area of inlet openings, in m2; and
V = wind speed, in m/h.
NOTE — For wind data at a place, the local Meteorological
Department may be consulted.
5.6.1.2 Stack effect (thermal action)
Ventilation due to convection effects arising from
temperature difference between inside and outside is
given by:
Qt = 7.0 A yjh (tT-t0)
where
Qr = rate of air flow, in m3/h;
A = free area of inlet openings, in m2;
h = vertical distance between inlets and outlets,
in m;
tT = average temperature of indoor air at height
h, in °C; and
t0 = temperature of outdoor air, in °C.
NOTE — The equation is based on 0.65 times the effectiveness
of openings. This should be reduced to 0.50, if conditions are
not favourable.
5. 6. 1.3 When areas of inlet and outlet openings are
unequal, the value of A may be calculated using the
equation:
_2_
~7
1 1
■ + -
^inlet Outlet
5.6. 1.4 Combined Effect of Wind and Thermal Action
When both forces (wind and thermal) act together in
the same direction, even without interference, the
Wind velocity and direction, outdoor temperature, and
indoor distribution cannot be predicted with certainty,
and refinement in calculation is not justified. A simple
method is to calculate the sum of the flows produced
by each force separately. Then using the ratio of the
flow produced by thermal forces to the aforementioned
sum, the actual flow due to the combined forces can be
approximated from Fig. 10. When the two flows are
equal, the actual flow is about 30 percent greater than
the flow caused by either force acting independently
(see Fig. 10).
7
6
5
4
3
2
1
0 20 40 60 80 100
FLOW DUE TO TEMPERATURE
DIFFERENCE AS PERCENT OF TOTAL
Fig. 10 Determination of Flow Caused by
Combined Forces of Wind and Temperature
Difference
Judgment is necessary for proper location of openings
in a building specially in the roof, where heat, smoke
and fumes are to be removed. Usually, windward
? lu
Ll LU
ll o£
O LU
uii
Ql Q
(- LU
U)
<
_l LU
LL F¬
<
3
I—
o
<
o
t-
LU
3
Q
44
NATIONAL BUILDING CODE OF INDIA 2016
monitor openings should be closed, but if wind is so
slight that temperature head can overcome it, all
openings may be opened.
5. 6. 1.5 For method for determining the rate of
ventilation based on probable indoor wind speed with
typical illustrative example for residential building,
reference may be made to A-4 of good practice [9- 1 (6)].
5.6.2 Mechanical Ventilation
The determination of rate of ventilation in case of
mechanical ventilation shall be done in accordance with
Part 8 ‘Building Services, Section 3 Air Conditioning,
Heating and Mechanical Ventilation’ of the Code.
5.6.3 Combined effect of Different Methods of
Ventilation
When combination of two or more methods of general
ventilation is used, the total rate of ventilation shall be
reckoned as the highest of the following three, and this
rule shall be followed until an exact formula is
established by research:
a) 1.25 times the rate of natural ventilation,
b) Rate of positive ventilation, and
c) Rate of exhaust of air.
5.6.4 Measurement of Air Movement
The rate of air movement of turbulent type at the
working zone shall be measured either with a Kata
thermometer (dry silvered type) or heated thermometer
or properly calibrated thermocouple anemometer.
Whereas anemometer gives the air velocity directly,
the Kata thermometer and heated thermometer give
cooling power of air and the rate of air movement is
found by reference to a suitable nomogram using the
ambient temperature.
5.7 Energy Conservation in Ventilation System
5.7.1 Maximum possible use should be made of wind
induced natural ventilation. This may be accomplished
by following the design guidelines given in 5.7.1. 1.
5.7.1. 1 Adequate number of circulating fans should be
installed to serve all interior working areas during summer
months in the hot dry and wann humid regions to provide
necessary air movement at times when ventilation due to
wind action alone does not afford sufficient relief.
5. 7. 1.1.1 The capacity of a ceiling fan to meet the
requirement of a room with the longer dimension D
metre should be about 55 D m3/min.
5. 7. 1.1.2 The height of fan blades above the floor
should be (3 H + W)/4, where H is the height of the
room, and W is the height of work plane.
5.7. 1.1. 3 The minimum distance between fan blades
and the ceiling should be about 0.3 m.
5.7.2 Electronic regulators should be used instead of
resistance type regulators for controlling the speed of
fans.
5.7.3 When actual ventilated zone does not cover the
entire room area, then optimum size of ceiling fan
should be chosen based on the actual usable area of
room, rather than the total floor area of the room. Thus
smaller size of fan can be employed and energy saving
could be achieved.
5.7.4 Power consumption by larger fans is obviously
higher, but their power consumption per square metre
of floor area is less and service value higher. Evidently,
improper use of fans irrespective of the rooms’
dimensions is likely to result in higher power
consumption. From the point of view of energy
consumption, the number of fans and the optimum sizes
for rooms of different dimensions are given in Table 13.
Table 13 Optimum Size/Number of Fans for Rooms of Different Sizes
(Clause 5.7.4)
SI Room
No. Width
m
(1)
(2)
4 m
(3)
5 m
(4)
6 m
(5)
7 m
(6)
8 m
(7)
9 m
(8)
10 m
(9)
11 m
(10)
12 m
(11)
14 m
(12)
16 m
(13)
i)
3
1 200/1
1 400/1
1 500/1
1 050/2
1 200/2
1 400/2
1 400/2
1 400/2
1 200/3
1 400/3
1 400/3
ii)
4
1 200/1
1 400/1
1 200/2
1 200/2
1 200/2
1 400/2
1 400/2
1 500/2
1 200/3
1 400/3
1 500/3
hi)
5
1 400/1
1 400/1
1 400/2
1 400/2
1 400/2
1 400/2
1 400/2
1 500/2
1 400/3
1 400/3
1 500/3
iv)
6
I 200/2
1 400/2
900/4
1 050/4
1 200/4
1 400/4
1 400/4
1 500/4
1 200/6
1 400/6
1 500/6
v)
7
1 200/2
1 400/2
1 050/4
1 050/4
1 200/4
1 400/4
1 400/4
1 500/4
1 200/6
1 400/6
1 500/6
Vi)
8
1 200/2
1 400/2
1 200/4
1 200/4
1 200/4
1 400/4
1 400/4
1 500/4
1 200/6
1 400/6
1 500/6
vii)
9
1 400/2
1 400/2
1 400/4
1 400/4
1 400/4
1 400/4
1 400/4
1 500/4
1 400/6
1 400/6
1 500/6
viii)
10
1 400/2
1 400/2
1 400/4
1 400/4
1 400/4
1 400/4
1 400/4
1 500/4
1 400/6
1 400/6
1 500/6
ix)
11
1 500/2
1 500/2
1 500/4
1 500/4
1 500/4
1 500/4
1 500/4
1 500/4
1 500/6
1 500/6
1 500/6
x)
12
I 200/3
1 400/3
1 200/6
1 200/6
1 200/6
1 400/6
1 400/6
1 500/6
1 200/7
1 400/9
1 400/9
xi)
13
1 400/3
1 400/3
1 200/6
1 200/6
1 200/6
1 400/6
1 400/6
1 500/6
1 400/9
1 400/9
1 500/9
xii)
14
1 400/3
1 400/3
1 400/6
1 400/6
1 400/6
1 400/6
1 400/6
1 500/6
1 400/9
1 400/9
1 500/9
Optimum Size, mm/Number of Fans
for Room Length
PART 8 BUILDING SERV ICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
45
ANNEX A
{Clause 3.4. 1 )
METHOD OF CALCULATING SOLAR LOAD ON VERTICAL
SURFACES OF DIFFERENT ORIENTATION
A-l DETAILS OF CALCULATION
A-l.l The solar energy above the earth’s atmosphere
is constant and the amount incident on unit area normal
to sun's rays is called solar constant (1.360 8 kWm J
or 2 cal/cirr/min). This energy, in reaching the earth's
surface, is depleted in, the atmosphere due to scattering
by air molecules, water vapour, dust particles, and
absorption by water vapour and ozone. The depletion
varies with varying atmospheric conditions. Another
important cause of depletion is the length of path
traversed by sun’s rays through the atmosphere. This
path is the shortest when sun is at the zenith and, as the
altitude of the sun decreases, the length of path in the
atmosphere increases. Figure 1 1 gives the computed
incident solar energy/hour on unit surface area normal
to the rays under standard atmospheric conditions ( see
Note below) for different altitudes of the sun.
NOTE — The standard atmospheric conditions assumed for
this computation are: cloud-free, 300 dust particles per cm3,
15 mm of precipitable water, 2.5 mm of ozone, at sea level.
A-1.2 In order to calculate the solar energy on any
surface other than normal to the rays, the altitude of
the sun at that time should be known. The corresponding
value of direct solar radiation (/N) should then be found
with the help of Fig. 12. The solar radiation incident
on any surface (7S) is given by:
Is = /N (sin (3 sin <j> + cos p cos a cos <|>)
where
P = solar altitude,
(J) = angle tilt of the surface from the vertical
(see Fig. 12), and
a = wall solar azimuth angle.
A-2 EXAMPLE TO FIND OUT ORIENTATION
ON THE BASIS OF SOLAR LOAD
A-2.1 Example
A-2. 1.1 As an example, a simple building with flat
roof, 10 m x 20 m, and 4 m high is dealt with below.
For the sake of generalization, no shading device or
verandah is taken.
A-2. 1.2 As the roof is horizontal, it will receive the
same solar heat in any orientation.
A-2. 1.3 The area of the vertical surfaces are 4 m x
1 0 in —A (say) and 4 m x 20 m = 2.4. Since, the external
wall surface are not in shade except when the sun is
Fig. 1 1 Direct Solar Intensities Normal to Sun at
Sea Level for Standard Condition (Computed)
Fig. 12 Definition of Solar Angles
not shining on them, the total solar load in a day on a
surface can be obtained by multiplying the total load
per unit area per day ( see Table 3) by the area of the
surface. For four principal orientations of the building,
the total solar load on the building is worked out in
Table 14.
A-2. 1.4 From Table 14, it can be seen that for the above
type of building, orientation 3 (longer surface facing
North and South) is appropriate as it affords maximum
solar heat gain in winter and in summer. This is true for
all places of India from the point of solar heat gain. By
further increasing the length to breadth ratio, the
46
NATIONAL BUILDING CODE OF INDIA 2016
Table 14 Solar Heat Gained Due to Orientation of Buildings
(Clause A-2.1.3)
8° N THIRUVANANTHAPURAM
13° N CHENNAI
May 16
Dec 22
May 16
Dec 22
1.
North
2 177 x a = 2 177A
—
1 625 x A = 1 625A
—
East
2 618 x 2A = 5 236A
2 177 x 2A = 4 354A
2 697 x 2A = 5 394A
2 019 x 2A = 4 038A
South
—
4 1 64 x A = 4 1 64 A
—
4 385 x A = 4 385A
West
2 618 x2A = 5 236A
2 177 x 2A = 4 354A
2 697 x 2A = 5 394A
2 019 x2A = 4 038A
Total
12 649 A
12 872A
12413A
12 461 A
2.
NE
2 650 x a = 2 650A
410 x a = 410A
2 492 x A = 2 492A
315 x A = 315A
SE
1 167 x 2A = 2 334A
3 391 x 2A = 6 782A
1 341 x 2A = 2 682A
3 423 x 2A = 6 846A
SW
1 167 x 2A = 2 334A
3 391 x a = 3 391A
1 341 x A=1 341 A
3 423 x A = 3 423A
NW
2 650 x 2A = 5 300A
410 x 2A = 820A
2 492 x a = 4 984A
315 x 2 A = 630 A
Total
12 618A
1 1 403A
1 1 499A
11 214A
3.
North
2 177 x2A = 4 354A
—
1 625 x 2A = 3 250A
—
East
2618x A = 2618A
2 177 x a = 2 177A
2 697 x A = 2 697A
2019x A = 2019A
South
—
4 164 x 2A - 8 328A
—
4 385 x 2A = 8 770A
West
2 618 x A = 2 618A
2 177 x A = 2 177A
2 697 x a = 2 697A
2 019 x A = 2 019A
Total
9 590A
12 602A
8 644A
12 808A
4.
NE
2 650 x 2A = 5 3 00 A
—
2 492 x A = 4 984A
315 x2A = 630A
SE
1 167 x A = 1 167A
2 177 x a = 2 177A
1 341 x A = 1 341 A
3 423 x A = 3 423A
SW
1 167 x 2A = 2 334A
4 164 x 2A = 8 328 A
1 341 x 2A = 2 682A
3 423 x 2A = 6 846A
NW
2 650 x a = 2 650A
2 177 x A = 2 177A
2 492 x A = 2 492A
315 x A = 315A
Total
1 1 451 A
12 682A
1 1 499A
11 214A
19° N MUMBAI
23° N KOLKATA
May 16
Dec 22
May 16
Dec 22
1.
North
962 x A = 962A
—
741 x A = 741 A
—
East
2 795 x 2A = 5 590A
1 830 x 2A = 3 660A
2 871 x 2A = 5 742A
1 703 x 2A = 3 406A
South
—
4 574 x A = 4 574A
205 x A = 205A
4 637 x A = 4 637A
West
2 795 x 2A = 5 590A
1 830 x 2A = 3 660A
2 871 x 2A = 5 742A
1 703 x 2A = 3 406A
Total
12 142 A
1 1 894A
12 430A
1 1 449A
2.
NE
2 255 x a = 2 255A
237 x A = 237A
2 192 x A = 2 192A
173 x A= 173A
SE
1 640 x 2A = 3 280A
3 438 x 2A = 6 876A
1 845 x 2A = 3 690A
3 454 x 2A = 6 908A
SW
1 640 x A = 1 640 A
3 438 x a = 3 438A
1 845 x A = 1 845A
3 454 x A = 3 454A
NW
2 255 x 2A = 4 510A
237 x 2A = 474A
2 192 x 2A = 4 3 84 A
173 x 2A = 346A
Total
11 685A
1 1 025A
12 1 1 1 A
10 881 A
3.
North
962 x 2A = 1 924A
—
741 x 2A= 1 482A
—
East
2 795 x A = 2 795A
1 830 x A= 1 830A
2 871 x A = 2 871A
1 703 x A= 1 703A
South
—
4 574 x 2A = 9 MSA
205 x 2A = 410A
4 637 x 2A = 9 274A
West
2 795 x A = 2 795A
1 830 xa= 1 830A
2 871 x a = 2 871A
1 703 x a= 1 703 A
Total
7 514A
12 808 A
7 634A
12 680A
4.
NE
2 255 x 2A = 4 510A
237 x 2A-= 474A
2 192 x 2 A = 4 3 84 A
173 x 2A = 346A
SE
1 640 x A = 1 640A
3 438 x A = 3 438A
1 845 x A = 1 845 A
3 454 x A = 3 454A
SW
1 640 x 2A = 3 280A
3 438 x 2A = 6 876A
1 845 x 2A = 3 690A
3 454 x 2A = 6 908A
NW
2 255 x A = 2 255A
237 x A = 237A
2 192 x a = 2 192 A
173 x A = 173A
Total
1 1 685A
1 1 025A
12 1 1 1 A
10 881 A
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
47
Table 14 — ( Concluded )
29° N DELHI
May 16
Dec 22
1. North
East
South
West
536 x A = 536A
2 950 x 2A = 5 900A
741 x a = 741A
2 950 x 2A = 5 900A
1 467 x 2A = 2 934A
4 543 x A = 4 543A
1 467 x 2A = 2 934A
Total
13 077A
10 41 1 A
2. NE
SE
SW
NW
2098 x A = 2098A
2 192 x 2A = 4 384A
2 192 x A = 2 192 A
2 098 x 2A = 4 196A
110x A= 110A
3 265 x 2A = 6 530A
3 265 x A = 3 265A
1 10 x 2A = 220A
Total
12 870A
10 125 A
3. North
536 x 2A= 1 072A
—
East
2 950 x A = 2 950A
1 467 x A= 1 467A
South
741 x 2A= 1 482A
4 543 x 2A = 9 086A
West
2 950 x A = 2 950A
1 467 x A = 1 467A
Total
8 454A
12 020 A
4. NE
2 098 x 2A = 4 196A
110 x 2A = 220A
SE
2 192 x A = 2 192 A
3 265 x A = 3 265A
SW
2 192 x 2A = 4 384A
3 265 x 2A = 6 530A
NW
2 098 x A = 4 196A
110x A=110A
Total
12 870A
10 125 A
A
2A
A
TYPE I
TYPE IV
advantage of this orientation will be more pronounced.
It may also be noted that in higher altitudes, the relative
merit of this orientation is more.
A-2.1.5 It is also seen that the total solar heat on the
building is the same for orientation 2 and 4. But if the
site considerations require a choice between these two,
orientation 2 should be preferred at places north of
latitude 23 °N and orientation 4 at southern places. This
is so because the total solar load per unit area in summer
on the north western wall decreases with the increase
in latitude and that on the south western wall increases.
It would, therefore, be advantageous to face only
smaller surface of the building to greater solar load in
the summer afternoons, when the air temperature also
is higher.
A-2.1.6 At hill stations, winter season cause more
discomfort and so sole criterion for optimum orientation
should be based on receiving maximum solar energy
on building in winter.
48
NATIONAL BUILDING CODE OF INDIA 2016
ANNEX B
(' Clauses 4.2.5, 4. 2. 5. 2, 4.2. 5. 4 and 4.2.6. 1)
SKY COMPONENT TABLES
B-l DESCRIPTION OF TABLES
B-l.l The three sky component tables are as given
below:
a) Table 1 5 — Percentage sky components on
the horizontal plane due to a
vertical rectangular opening for
the clear design sky.
b) Table 1 6 — Percentage sky components on
the vertical plane perpendicular
to a vertical rectangular opening
for the clear design sky.
c) Table 1 7 — Percentage sky components on
the vertical plane parallel to a
vertical rectangular opening for
the clear design sky.
B-l. 2 All the tables are for an unglazed opening
illuminated by the clear design sky.
B-l. 3 The values tabulated are the components at a
point P distant from the opening on a line perpendicular
to the plane of the opening through one of its lower
corners, and / and h are the width and height
respectively of the rectangular opening {see Fig. 13).
Fig. 13
B-1.4 Sky component for different h/d and Hd values
are tabulated, that is, for windows of different size and
for different distances of the point P from the window.
B-1.5 By suitable combination of the values obtained
from the three tables, for a given point for a given
window, the sky component in any plane passing
through the point may be obtained.
B-l. 6 Method of Using the Tables
B-l. 6.1 Method of using the Tables to get the sky
component at given point is explained with help of the
following example.
B-l. 6.2 Example
It is desired to calculate the sky component due to a
vertical window ABCD with width 1 .8 m and height
1 .5 m at a point P on a horizontal plane 3.0 m from the
window wall located as shown in the Fig. 14. Foot of
the perpendicular N is 0.6 m below the sill and 0.9 m
to the left of AD.
0.9 m , 1.8 m
D'
D
C
E
IjO
A'
A
B
E
Fig. 14
Consider ABCD extended to NB'CD'
1) For NB'CD'
l/d = (1.8 + 0.9)/3 = 0.9
h/d = (1.5 + 0.6)/3 = 0.7
F, = 5.708 percent (from Table 15)
2) For NA'DD'
l/d = 0.9/3 = 0.3
h/d — (1.5 + 0.6)/3 = 0.7
F2 = 2.441 percent (from Table 15)
3) For NB'BA'
l/d= (1.8 + 0.9)/3 = 0.9
h/d= 0.6/3 = 0.2
F3= 0.878 percent (from Table 15)
4) For NA'AA'
l/d= 0.9/3 =0.3
h/d= 0.6/3 = 0.2
F = 0.403 percent (from Table 15)
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
49
Since ABCD = NB 'CD '-NA 'DD '-NB 'BA ' + NA 'A A '
Sky Component, F = Fx- F2- F3 + F4
= 5.708 - 2.441 - 0.878 + 0.403
= 2.792
B-2 GENERAL INSTRUCTIONS
B-2.1 For irregular obstructions like row of trees
parallel to the plane of the window, equivalent straight
boundaries horizontal and vertical, may be drawn.
B-2. 2 For extremely irregular obstruction or
obstructions not in a plane parallel to the window,
diagrammatic methods, such as Waldrams diagrams
may have to be employed.
B-2.3 For bay windows, dormer windows or comer
windows the effective dimensions of window opening
computed should be taken when using the tables to find
the sky components.
B-3 CALCULATION OF IRC
B-3.1 The internal reflected component is a variable
quantity which varies from point to point in a room'
depending upon the interior finish. IRC value is
maximum at the centre of the room and decreases
elsewhere in all directions. For processing calculations
of IRC at any given point of the room, special
techniques have to be made out. The internal reflected
component may be calculated by using the formula:
0.85 W
IRC = - ( CRfo, + 1 0 IFy, )
A(l-R) ^ W
Rfw = average reflection factor of the floor and
those parts of the wall below the plane of
the mid-height of the window (excluding the
window wall);
Rcw = average reflection factor of the ceiling and
those parts of the wall above the plane of
the mid-height of the window (excluding the
window wall);
A = area of all the surfaces in the room (ceiling
walls, floor and windows); and
R = average reflection factor of all surfaces in
the room (ceiling, walls, floor and windows)
expressed as a decimal part of unity.
B-3.2 Example
Consider two rooms of dimensions:
Room X= 6 m (/) x 5 m (w) x3ra ( ht )
Room Y- 3.7 m x 3 m x 3 m
Let the window area be 1 5 percent of the floor area
and be glazed.
Window size in room X— 2.5 m x 1.8 m
Window size in room 3.7 m x 3 m
The window are on the Y = 6 m x 3 m side in room X
and 3.7 m x 3 m side in room Y, and the sill heights are
0.9 m from floor level.
Reflection coefficients of:
where
walls and ceiling = 70 percent
W = window area;
C = constant of value 78 when there is no external
obstruction but it has different values as
shown in the following table when there are
obstructions:
Angle of
Obstruction
Degree
(1)
Sky + External
Obstruction, C
(2)
5
68.9
15
50.6
25
36.2
35
26.7
45
20.1
55
15.8
65
12.9
75
11.1
85
10.36
floor = 20 percent
glazing =15 percent
Value of IRC in room X:
a) Total interior area, ,4=2 (3 0+18+1 5)
= 126 m2
b) Average reflection factor of interior:
D 61.5x0.7 + 30x0.7+30x0.2 + 4.5x0.15 A
K = - = 0.56
61.5 + 30 + 30 + 4.5
c) l - R — 0.44
d) Mid-height of window is 1.83 m from floor,
average reflection factor of room below
1 .83 m level excluding the wall containing the
window:
Rfw _
29.28x0.7 + 30x0.2
29.28 + 30
= 0.45
50
NATIONAL BUILDING CODE OF INDIA 2016
e) Average reflection factor of room above
1 .83 m level excluding the wall containing the
window:
18.72x0.7 + 30x0.7
Rcw = - = 0.7
18.72 + 30
f) IRC = -0:83-*-4'5 (78 x 0.45 + 10 x 0.7)
126 x 0.44 v ’
= 2.904
Value of IRC in room Y:
a) Total interior area:
A = 2(3.7 x3 + 3.7x3 + 3x3) = 62.4 m2
b) Average reflection factor:
38x55x0.7x3x0.7 + 3.7x3
XO-2 + 1.5X1.1XOJ5
38.55 + 1 1.1 + 1 1.1 + 1.65
c) Mid-height of window from floor = 1 .46 m
d) Average reflection factor below 1 .46 m level
„ 3.7x3x0.7 + 1.54x9.7x0.7
iVf- — — U. /
* 11.1 + 14.94
e) Average reflection factor above 1 .46 m level
3.7x3x0.7 + 1.54x9.7x0.7 n „
R = - = 0.7
cw 11.1 + 14.94
IRC = Q-85.xl-.65 .(78 x o 48 + io x o.7)
62.4 x 0.404 v ’
= 2.472
B-4 GENERAL NOTE ON DAYLIGHTING OF
BUILDNG
B-4.1 The main aim of day lighting design is how to
admit enough light for good visibility without setting
up uncomfortable glare. No simple solution may be
given as the sky varies so much in its brightness from
hour to hour, and from season to season.
B-4.2 Different visual tasks need differing amounts of
lights for the same visual efficiency. The correct amount
of light for any task is determined by the following:
a) Characteristics of the tasks — Size of
significant detail, contrast of detail with
background and how close it is to the eyes;
b) Sight of the worker — For example, old
people need more light;
c) Speed and accuracy necessary in the
performance of work. If no errors are
permissible, much more light is needed; and
d) Ease and comfort of working — Long and
sustained tasks shall be done easily whereas
workers can make a special effort for tasks of
very short duration.
These factors have been made the subject of careful
analysis as a result of which tables of necessary levels
of illumination have been draw up.
B-4.3 Levels of lighting determined analytically shall
be translated into levels of daylight and then into size
of window opening or vice versa for checking the size
of window assumed for required levels of daylight.
B-4.4 One of the many important factors involved in
the translation is the lightness of the room surface. The
illumination levels in a given room with a finite window
will be higher when the walls are light coloured than
when these are dark coloured. It is necessary, therefore,
at an early stage to consider the colouring of the rooms
of the building and not to leave this until later. Lighting
is not merely a matter of window openings and quite
half the eventual level of lighting may be dependent on
the decoration in the room. Whatever may be the colour
the occupant wants to use, it is most desirable to
maintain proper values of reflectance factors for ceiling,
wall and floors so that the level of daylight illumination
is maintained.
PART 8 BUILDING SERVICES
SECTION 1 LIGHTING AND NATURAL VENTILATION
51
Table 15 Percentage Sky Components on the Horizontal Plane Due to a Vertical
Rectangular Opening for the Clear Design Sky
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NATIONAL BUILDING CODE OF INDIA 2016
Table 16 Percentage Sky Components on the Vertical Plane Perpendicular
to a Vertical Rectangular Opening for the Clear Design Sky
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«
PART 8 BUILDING SERVICES — SECTION 1 LIGHTING AND NATURAL VENTILATION
Table 17 Percentage Sky Components on the Vertical Plane Parallel
to a Vertical Rectangular Opening for the Clear Design Sky
(' Clause B-l.l)
5.766
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ON
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54
NATIONAL BUILDING CODE OF INDIA 2016
5.0 3.893 7.672 11.241 14.529 17.494 20.125 22.430 24.432 26.161 27.650 28.932 30.035 30.986 31.808 32.521 33.142 33.683 34.157 34.574 34.943 37.028 37.834 38.214 38.696 38.781
10.0 3.897 7681 11.254 14.546 17.515 20.150 22.459 24.466 26.199 27.693 28.978 30.085 31.041 31.867 32.584 33.208 33.753 34.231 34.652 35.024 37.144 37.978. 38.382 38.927 39.057
INF 3.898 7.682 11.256 44.548 17.518 20.154 22.464 24.471 26.205 27.699 28.985 30.093 31.049 31.876 32.593 33.218 33.764 34.243 34.664 35.037 37.162 38.003 38.411 38.978 39.172
LIST OF STANDARDS
The following list records those standards which are IS No.
acceptable as ‘good practice’ and ‘accepted standards’
in the fulfillment of the requirements of the Code. The
7942 : 1976
latest version of a standard shall be adopted at the time
of enforcement of the Code. The standards listed may
(5)
1944
be used by the Authority for conformance with the
(Parts 1 and 2)
requirements of the referred clauses in the Code.
1970
In the following list, the number appearing in first
column within parentheses indicates the number of the
reference in this Section.
Part 6 : 1981
IS No.
Title
2672 : 1966
(1) 7662
Recommendations for orientation
4347 : 1967
(Part 1) : 1974
of buildings: Part 1 Non-industrial
buildings
6074 : 1971
(2) 3646
Code of practice for interior
(Part 1) : 1992
illumination: Part 1 General
requirements and recommen¬
dations for building interiors ( first
6665 : 1972
revision )
10894 : 1984
(3) 2440 : 1975
Guide for daylighting of buildings
(second revision )
10947 : 1984
(4) 6060 : 1971
Code of practice for daylighting
of factory buildings
(6)
3362 : 1977
Title
Code of practice for daylighting
of educational buildings
Code of practice for lighting of
public thoroughfares:
: Parts 1 and 2 For main and
secondary roads (Group A and B)
( first revision)
Lighting for town and city centres
and areas of civic importance
(Group E)
Code of practice for library lighting
Code of practice for hospital
lighting
Functional requirements of hotels,
restaurants and other food service
establishments
Code of practice for industrial
lighting
Code of practice for lighting of
educational institutions
Code of practice for lighting for
ports and harbours
Code of practice for natural
ventilation of residential buildings
(first revision )
PART 8 BUILDING SERVICES
SECTION 1 LIGHTING AND NATURAL VENTILATION
55
NATIONAL BUILDING CODE OF INDIA
PART 8 BUILDING SERVICES
Section 2 Electrical and Allied Installations
BUREAU OF INDIAN STANDARDS
CONTENTS
FOREWORD ... 3
1 SCOPE ... 7
2 TERMINOLOGY AND CONVENTIONAL SYMBOLS ... 7
3 GENERAL REQUIREMENTS ... 17
4 PLANNING OF ELECTRICAL INSTALLATIONS ... 18
5 DISTRIBUTION OF SUPPLY AND CABLING ... 30
6 WIRING ... 47
7 FITTINGS AND ACCESSORIES ... 56
8 EARTHING ... 61
9 INSPECTION, TESTING AND VERIFICATION OF INSTALLATION ... 72
10 ALLIED/MISCELLANEOUS SERVICES ... 77
1 1 LIGHTNING PROTECTION OF BUILDINGS ... 8 1
12 ELECTRICAL INSTALLATIONS FOR CONSTRUCTION AND DEMOLITION ... 1 1 1
SITES
1 3 PROTECTION OF HUMAN BEINGS FROM ELECTRICAL HAZARDS ... 1 1 8
ANNEX A
DRAWING SYMBOLS FOR ELECTRICAL INSTALLATIONS
IN BUILDINGS
...124
ANNEX B
EXTRACTS FROM CENTRAL ELECTRICIT Y AUTHORITY
(MEASURES RELATING TO SAFETY AND ELECTRIC SUPPLY)
REGULATION, 2010 FURTHER AMENDED IN 2015
...129
ANNEX C
AREA REQUIRED FOR TRANSFORMER ROOM AND
SUBSTATION FOR DIFFERENT CAPACITIES
...150
ANNEX D
ADDITIONAL AREA REQUIRED FOR GENERATOR IN ELECTRIC
SUBSTATION
...150
ANNEXE
CHECKLIST FOR INSPECTION, HANDING OVER AND
COMMISSIONING OF VARIOUS EQUIPMENT OF SUBSTATION
...151
ANNEX F
CHECKLIST FOR INSPECTION, HANDING OVER AND
COMMISSIONING OF EARTHING PITS
...161
ANNEX G
FORM OF COMPLETION CERTIFICATE
...163
LIST OF STANDARDS
...166
2
NATIONAL BUILDING CODE OF INDIA 2016
National Building Code Sectional Committee, CED 46
FOREWORD
This Code (Part 8/Section 2) covers essential requirements for electrical and allied installations in buildings.
This Section was first published in 1970 and was subsequently revised in 1983 and 2005. In the first revision,
general guidance for electrical wiring installation in industrial location where voltage supply normally exceeds
650 V was included. This Section was also updated based on the existing version of the Indian Standards. The
importance of pre-planning and exchange of information among all concerned agencies from the earlier stages of
building work was emphasized.
In the second revision of 2005, the title of this Section was modified from the erstwhile ‘Electrical Installations’
to ‘Electrical and Allied Installations’ to reflect the provisions included on certain allied installations. The significant
changes incorporated in the last revision included, thorough change in the risk assessment procedure for lightning
including some other changes in the provision of lightning protection of building; alignment of some of the
provisions of wiring with the practices prevalent at that time; modification of definitions in line with terminologies
used at national and international level and addition of some new definitions; incorporation of provisions on
installation of distribution transformer inside the multi-storeyed building; introduction of concept of energy
conservation in lighting and introduction of concept of various types of earthing in building installation.
All electrical installations in India come under the purview of The Indian Electricity Act, 2003 and the rules and
regulations framed thereunder. In the context of the buildings, both buildings (the structure itself) and the building
services (not just the electrical services, but all other services that use electricity or have an interface with the
electrical system) are required to follow these. The erstwhile Indian Electricity Rules, 1956 were superseded by
various Central Electricity Authority Regulations. While revising the provisions of this Section of the Code, care
has been taken to align the same with the provisions of the relevant regulations, particularly, Central Electricity
Authority (Measures Relating to Safety and Electric Supply) Regulations, 2010, amended in 2015. In this revision,
in addition to above, the following major modifications have been incorporated:
a) Various new terms and their definitions have been added and existing terms and definitions have also
been updated based on current developments at national and international level.
b) Provisions relating to location and other requirements relating to layout, environmental and safety aspects
for different substation apparatus/equipment and generating sets have been reviewed and updated.
c) Provisions relating to location of compact substations have been added.
d) Requirements for electrical supply system for life and safety services have been included.
e) Provisions relating to reception and distribution of supply and wiring installations have been updated
with due cognizance to Indian Standards formulated for various wiring systems.
f) Provisions relating to installation of energy meters have been updated.
g) Discrimination, cascading and limitation concepts for the coordination of protective devices in electrical
circuits have been introduced.
h) Socket outlets with suitable circuit breakers, conforming to following Indian Standards have been
recommended for industrial and commercial applications, either indoors or outdoors:
1) 1S/1EC 60309-1:2002 ‘Plugs, socket-outlets and couplers for industrial purposes — Part 1:
General requirements’; and
2) 1S/1EC 60309-2:2002 ‘Plugs, socket-outlets and couplers for industrial purposes — Part 2:
Dimensional Interchangeability Requirements for Pin and Contact-Tube Accessories’.
j) Provisions relating to earthing/grounding have been substantially revised and updated.
k) Provisions relating to lightning protection of buildings have been revamped based on the current national
and international developments.
m) Provisions relating to renewable energy sources for building, such as solar PV system; aviation obstacle
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
3
lights; electrical supply for electric vehicle charging and car park management; etc, have been included.
n) New provisions relating to electrical installations for construction sites and demolition sites have been
included.
p) New provisions relating to protection of human beings from electrical hazards and protection against
fire in the building due to leakage current have been included.
q) Typical formats for checklists for handing over and commissioning of substation equipment and earthing
pit have been included.
This Section has to be read together with Part 8 ‘Building Services, Section 1 Lighting and Natural Ventilation’ of
the Code for making provision for the desired levels of illumination as well as ventilation for different locations
in different occupancies; and also with Part 4 ‘Fire and Life Safety’ of the Code for list of emergency fire and life
safety services and other sections of Part 8 ‘Building Sendees’ and Part 9 ‘Plumbing Services’ for electricity
related requirements and integration thereof. Utmost importance should be given in the installation of electrical
wiring to prevent short circuiting and the hazards associated therewith.
Notwithstanding the provisions given in this Section and the National Electrical Code, 201 1 the provisions of the
Indian Electricity Act, 2003 and the rules and regulations framed thereunder have to be necessarily complied
with.
The information contained in this Section is largely based on the following Indian Standards/Special Publication:
IS 732 : 1989
IS 3043 : 1987
IS 4648: 1968
IS 12032 (Part 11): 1987
IS/IEC 62305-1 : 2010
IS, TEC 62305-2 : 2010
ISTEC 62305-3 : 2010
ISTEC 62305-4:2010
SP 30:2011
Code of practice for electrical wiring installations (third revision ) ( under revision )
Code of practice for earthing (first revision) ( under revision )
Guide for electrical layout in residential buildings
Specification for graphical symbols for diagrams in the field of electro technology:
Part 11 Architectural and topographical installation plan and diagrams
Protection against lightning: Part 1 General principles
Protection against lightning: Part 2 Risk management
Protection against lightning: Part 3 Physical damage to structures and life hazard
Protection against lightning: Part 4 Electrical and electronic systems within structures
National Electrical Code, 2011 (first revision)
It may be noted that some of the above standards are currently under revision. The revised version when available
should also be referred.
Considerable assistance has also been drawn from following International Standards while formulating this Section:
IEC 60364-4-41 : 2005
IEC 60364-4-43 : 2008
IEC 60364-4-44 : 2007
IEC 60364-5-51 : 2005
IEC 60364-5-54:2011
IEC 60364-7 series
IEC 61439-1 : 2011
IEC 61439-2: 2011
IEC 61439-6 : 2012
Low- voltage electrical installations — Part 4-4 1 : Protection for safety — Protection
against electric shock
Low- voltage electrical installations — Part 4-43: Protection for safety — Protection
against overcurrent
Low- voltage electrical installations — Part 4-44: Protection for safety — Protection
against voltage disturbances and electromagnetic disturbances
Electrical installations of buildings — Part 5-51: Selection and erection of electrical
equipment — Common rules
Low-voltage electrical installations — Part 5-54: Selection and erection of electrical
equipment — Earthing arrangements and protective conductors
Low-voltage electrical installations — Part 7: Requirements for special installations
or locations
Low-voltage switchgear and controlgear assemblies and bus trunking — Part 1:
General rules
Low-voltage switchgear and controlgear assemblies and bus trunking — Part 2: Power
switchgear and controlgear assemblies
Low-voltage switchgear and controlgear assemblies and bus trunking — Part 6:
Busbar trunking systems (busways)
4
NATIONAL BUILDING CODE OF INDIA 2016
All standards, whether given herein above or cross-referred to in the main text of this Section, are subject to
revision. The parties to agreement based on this Section are encouraged to investigate the possibility of applying
the most recent editions of the standards.
For the purpose of deciding whether a particular requirement of this Section is complied with, the final value,
observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1 960
‘Rules for rounding off numerical values ( revised ?)’. The number of significant places retained in the rounded off
value should be the same as that of the specified value in this Section of the Code.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
5
*
NATIONAL BUILDING CODE OF INDIA
PART 8 BUILDING SERVICES
Section 2 Electrical and Allied Installations
1 SCOPE
This Code (Part 8/Section 2) covers the essentia!
requirements for electrical installations in buildings to
ensure efficient use of electricity including safety from
fire and shock. This Section also includes general
requirements relating to lightning protection of
buildings and brief provisions on certain allied
installations.
2 TERMINOLOGY AND CONVENTIONAL
SYMBOLS
2.1 For the purpose of this Section, the following
definitions shall apply. For definition of other terms,
reference may be made to accepted standards [8-2(1)].
2.1.1 Accessory — A device, other than current using
equipment, associated with such equipment or with the
wiring of an installation.
2.1.2 Apparatus — Electrical apparatus including all
machines, appliances and fittings in which conductors
are used or of which they form a part.
2.1.3 Appliance — An item of current using equipment
other than a luminaire or an independent motor.
2.1.4 Back-up Protection — Protection which is
intended to operate when a system fault is not cleared
or abnormal condition not detected in the required time,
because of failure or inability of other protection to
operate or failure of appropriate circuit-breaker to trip.
2.1.5 Barrier — A part providing a defined degree of
protection against contact with live parts, from any
usual direction of access.
2.1.6 Basic Protection — Protection against electric
shock under fault-free condition.
NOTE — For low voltage installations, systems and equipment,
basic protection generally corresponds to protection against
direct contact that is ‘contact of persons or live parts’.
2.1.7 Bonding Conductor — A protective conductor
providing equipotential bonding.
2.1.8 Bonding Ring Conductor (BRC) — A bus earthing
conductor in the form of a closed ring.
NOTE — Nonnally the bonding ring conductor, as part of the
bonding network, has multiple connections to the common
bonding network (CBN) that improves its performance.
2.1.9 Bunched — Cables are said to be ‘bunched’ when
two or more are contained within a single conduit, duct,
ducting, or trunking, or, if not enclosed, are not
separated from each other.
PART 8 BUILDING SERVICES
2.1.10 Buried Direct — A cable laid in the ground in
intimate contact with the soil.
2.1.11 Busbar Trunking System — A type-tested
assembly, in the form of an enclosed conductor system
comprising solid conductors separated by insulating
materials. The assembly may consist of units such as:
a) Busbur trunking units, with or without tap-off
facilities;
b) Tap-off units where applicable; and
c) Phase-transposition, expansion, building-
movement, flexible, end-feeder and adaptor
units.
2.1.12 Bypass Equipotential Bonding Conductor —
Bonding conductor connected in parallel with the
screens of cables.
2.1.13 Cable — A length of single-insulated conductor
(solid or stranded), or two or more such conductors,
each provided with its own insulation, which are laid
up together. The insulated conductor or conductors may
or may not be provided with an overall mechanical
protective covering.
2.1.14 Cable, Circuit Integrity — A cable which
continues to function, that is, maintains the continuity
of the circuit under circumstances of fire (against a
specified temperature and period of the test).
NOTE — For circuit integrity cable requirements reference may
be made to accepted standard [8-2(2)], which prescribes a fire
survival test at 750°C for 3 h.
2.1.15 Cable, Flame Retardant (FR) — A cable which
is flame retardant as per the accepted standard [8-2(3)].
2.1.16 Cable, Flame Retardant Low Smoke and
Halogen (FR-LSH) — A cable which is flame retardant
and emits low smoke and halogen as per the accepted
standard [8-2(3)].
2.1.17 Cable, Flexible — A cable containing one or
more cores, each formed of a group of wires, the
diameters of the cores and of the wires being sufficiently
small to afford flexibility.
2.1.18 Cable, Metcil-Sheathed — An insulated cable
with a metal sheath.
2.1.19 Cable, PVC Sheathed-Insulated — A cable in
which the insulation of the conductor is a
polyvinylchloride (PVC) compound; with PVC sheath
also providing mechanical protection to the conductor
core or cores in the cable.
— SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
2.1.20 Cable, Weatherproof — A cable so constructed
that when installed in uncovered locations, it will
withstand all kinds of weather variations (see 2.1.186
for definition of weatherproof).
2. 1 .2 1 Cable, XLPE — A cable in which the insulation
of the conductor is cross-linked polythene and the
mechanical protection is provided for the core or cores
by a sheath of a polyvinyl chloride compound.
2.1.22 Cable Armoured — A cable provided with a
wrapping of metal (usually in the form of tape or wire)
serving as a mechanical protection.
2.1.23 Cable Bracket — A cable support consisting of
single devices fixed to elements of building or plant
construction.
2.1.24 Cable Channel — An enclosure situated above
or in the ground, open or ventilated or closed, and
having dimensions which do not permit the access of
persons but allow access to the conductor and/or cables
throughout their length during and after installation.
NOTE — A cable channel may or may not form part of the
building construction.
2.1.25 Cable Cleat — A component of a support system
which consists of elements spread at intervals along
the length of the cable or conduits and which
mechanically retains the cable or conduit.
2.1.26 Cable Coupler — A means enabling the
connection, at will, of two flexible cables. It consists
of a connector and a plug.
2.1.27 Cable Ducting — A manufactured enclosure of
metal or insulating material, other than conduit or cable
trunking, intended for the protection of cables which
are drawn-in after erection of the ducting, but which is
not specifically intended to form part of a building
structure.
2.1.28 Cable Ladder — A cable support occupying less
than 10 percent of the plan area and consisting of a
series of supporting elements rigidly fixed to each other
or to a main supporting member or members.
2.1.29 Cable Raceways — An enclosed channel of
metal or non-metallic materials designed expressly for
holding wires, cables or busbars, with openable/
maintainable construction having provision of
ventilation. These include electrical non-metallic
tubing, electrical metallic tubing, underfloor raceways,
cellular concrete floor raceways, cellular metal floor
raceways, surface raceways and wireways.
2.1.30 Cable Tray — A cable support consisting of a
continuous base with raised edges and no covering. A
cable tray is considered to be non-perforated, where
less than 30 percent of the material is removed from
the base.
2.1.31 Cable Trunking — A factory made closed
support and protection system into which conductors
and/or cables are laid after removal of the cover.
2.1.32 Cable Tunnel — An enclosure (corridor)
containing supporting structures for conductors and/or
cables and joints and whose dimensions allow free
access to persons throughout the entire length.
2.1.33 Cartridge Fuse Link — A device comprising a
fuse element or several fuse elements connected in
parallel enclosed in a cartridge usually filled with an
arc-extinguishing medium and connected to
terminations. The fuse link is the part of a fuse which
requires replacing after the fuse has operated.
2.1.34 Ceiling Rose — A fitting (usually used to attach
to the ceiling) designed for the connection between the
electrical installation wiring and a flexible cord (which
is in turn connected to a lampholder).
2.1.35 Circuit — An assembly of electrical equipment
supplied from the same origin and protected against
overcurrent by the same protective device(s). Circuits
are categorized as follows:
a) Category 1 circuit — A circuit (other than a
fire alarm annunciation or emergency lighting
circuit and other circuits required to work
during fire in a building) operating at low
voltage and supplied directly from a mains
supply system.
b) Category > 2 circuit — With the exception of
Category 3 circuits, any circuit for extra low-
voltage (ELV)/telecommunication [for
example, radio, telephone, sound distribution,
building management system (BMS), public
address system (PAS), intruder alarm, bell and
call and data transmission circuits)] which is
supplied from a safety source.
c) Category 3 circuit — A fire alarm circuit or
an emergency lighting circuit and other
circuits required to work during fire in a
building.
2.1.36 Circuit Breaker — A mechanical switching
device, capable of making, carrying and breaking
currents under normal circuit conditions and also of
making, carrying for a specified time, and breaking
currents under specified abnonnal circuit conditions
such as those of short circuit.
NOTE — A circuit breaker is usually intended to operate
infrequently, although some types are suitable for frequent
operation.
2.1.36.1 Miniature circuit breaker (MCB) — A compact
mechanical switching device capable of making,
carrying and breaking currents under normal circuit
conditions and also making and carrying currents for
specified times and automatically breaking currents
8
NATIONAL BUILDING CODE OF INDIA 2016
under specified abnormal circuit conditions, such as
those of overload and short circuits.
2.1.36.2 Circuit breaker, linked — A circuit breaker,
the contacts of which are so arranged as to make or
break all poles simultaneously or in a definite sequence.
2.1.36.3 Moulded case circuit breaker ( MCCB ) — A
circuit breaker having a supporting housing of moulded
insulating material forming an integral part of the circuit
breaker.
2.1.36.4 Air circuit breaker (ACB) — A circuit breaker
in which the contacts open and close in air at
atmospheric pressure.
2.1.36.5 Residual current operated circuit breaker —
A mechanical switching device designed to make, carry
and break currents under normal service conditions and
to cause the opening of the contacts when the residual
current attains a given value under specified conditions.
2.1.36.5.1 Residual current operated circuit breaker
with integral overcurrent protection ( RCBO ) — A
residual current operated circuit breaker designed to
perform the functions of protection against overload
and/or short-circuit.
2.1.36.5.2 Residual current operated circuit breaker
without integral overcurrent protection ( RCCB ) — A
residual current operated circuit breaker not designed
to perform the functions of protection against overload
and/or short-circuits.
NOTE — Similar function is provided by earth leakage circuit
breaker (ELCB).
2.1.37 Circuit, Final Sub — An outgoing circuit
connected to one-way distribution board and intended
to supply electrical energy at one or more points to
current, using appliances without the intervention of a
further distribution board other than a one-way board.
It includes all branches and extensions derived from
that particular way in the board.
2.1.38 Circuit Integrity Cable Support and Fixing
Materials — Supports and fixing materials for
supporting circuit integrity cable ( see 2.1.14), which
continues in service after exposure to fire for a specified
duration.
2.1.39 Compact Substation or Prefabricated
Substation — Prefabricated and type-tested assembly
which can to be operated from inside (walk-in type) or
outside (non-walk-in type) comprising components
such as power transformer, high-voltage switchgear and
controlgear, low-voltage switchgear and controlgear,
corresponding interconnections (cable, busbar or other)
and-auxiliary equipment and circuits located next to
each other, maintaining segregation and integrity of
each compartment in which they are located along with
external interconnecting cables, earthing, protections,
etc. The components shall be enclosed, by either a
common enclosure or by an assembly of enclosures.
NOTE — See accepted standard [8-2(4)] for requirements of
prefabricated substation.
2. 1 .40 Conductor of a Cable or Core — The conducting
portion consisting of a single wire or group of wires,
assembled together and in contact with each other or
connected in parallel.
2.1.41 Conductor, Aerial — Any conductor which is
supported by insulators above the ground and is directly
exposed to the weather.
NOTE — Following four classes of aerial conductors are
recognized:
a) Bare aerial conductors,
b) Covered aerial conductors,
c) Insulated aerial conductors, and
d) Weatherproof neutral-screened cable.
2.1.42 Conductor, Bare — A conductor not covered
with insulating material.
2.1.43 Conductor, Earthed — A conductor with no
provision for its insulation from earth.
2.1.44 Conductor, Insulated — A conductor adequately
covered with insulating material of such quality and
thickness as to prevent danger.
2.1.45 Conduit — A part of a closed wiring system, a
circular or non-circular cross-section for conductors
and/or cables in electrical installations, allowing them
to be drawn in and/or replaced. Conduits should be
sufficiently closed-jointed so that the conductors can
only be drawn in and not inserted laterally.
2.1.46 Connector — The part of a cable coupler or of
an appliance coupler which is provided with female
contact and is intended to be attached to the flexible
cable connected to the supply.
2.1.47 Connector Box or Joint Box — Abox forming a
part of wiring installation, provided to contain joints
in the conductors of cables of the installations.
2.1.48 Connector for Portable Appliances — A
combination of a plug and socket arranged for
attachment to a portable electrical appliance or to a
flexible cord.
2.1.49 Consumer ’s Terminals — The ends of the
electrical conductors situated upon any consumer’s
premises and belonging to him, at which the supply of
energy is delivered from the service line.
2.1.50 Continuous Operating Voltage ( Uc ) —
Maximum rms voltage which may be continuously
applied to a surge protection device’s mode of
protection. This is equal to rated voltage.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
9
2.1.51 Cord, Flexible — A flexible cable having a large
number of (typically 1 6 or 23 or 46 or 89, etc) strands
of conductors of small cross-sectional area. Two
flexible cords twisted together are known as twin
‘flexible cord’.
NOTE — Large number of fine strands of wires for each
conductor makes the conductor capable of withstanding
frequent bends thereby improving their flexibility.
2.1.52 Core of a Cable — A single conductor of a cable
with its insulation but not including any mechanical
protective covering.
2.1.53 Current Carrying Capacity of a Conductor —
The maximum current which can be carried by a
conductor under specified conditions without its steady
state temperature exceeding a specified value.
2.1.54 Current Using Equipment — Equipment which
converts electrical energy in to another form of energy,
such as light, heat, or motive power.
2.1.55 Cut-out — Any appliance for automatically
interrupting the transmission of energy through any
conductor when the current rises above a pre¬
determined amount.
2.1.56 Damp Situation - — A situation in which moisture
is either permanently present or intermittently present
to such an extent as likely to impair the effectiveness
of an installation conforming to the requirements for
ordinary situations.
2.1.57 Danger — Danger to health or danger to life
or limb from shock, burn or injury from mechanical
movement to persons (and livestock where present),
or from fire attendant upon the use of electrical
energy.
2.1.58 Dead — A portion of an electrical circuit
(normally expected to carry a voltage) at or near earth
potential or apparently disconnected from any live
system. A circuit apparently disconnected from all
sources is expected to be at earth potential; but
capacitive storage of charge in cables, capacitors, etc,
can keep the electric circuit at a significant voltage (and
often dangerous voltages from aspects of shock). Such
circuits with storage components will be dead only on
connection to earth.
2.1.59 Design Current (of a Circuit) — The magnitude
of the current intended to be carried by the circuit in
normal service.
2.1.60 Direct Contact — Contact of persons or live
stock with live parts which may result in electric
shock.
2.1.61 Direct Earthing System — A system of earthing
in which the parts of an installation are so earthed as
specified, but are not connected within the installation
to the neutral conductor of the supply system or to earth
through the trip coil of an earth leakage circuit-breaker.
2.1.62 Disconnector — A mechanical switching device
which, in the open position, complies with the
requirements specified for the isolation function.
NOTES
1 A disconnector is otherwise known as isolator.
2 A disconnector is capable of opening and closing a circuit
when either a negligible current is broken or made, or when no
significant change in the voltage across the terminals of each
pole of the disconnector occurs. It is also capable of carrying
currents under normal circuit conditions and carrying for a
specified time, current under abnormal conditions, such as those
of short-circuit.
2.1.63 Discrimination (Over-Cwrent Discrimination) —
Coordination of the operating characteristics of two or
more over-current protective devices should be such
that, on the incidence of over-currents within stated
limits, the device intended to operate would be the
device closest to the point of fault or abnormality, and
if proper discrimination is achieved within these limits,
only that device closest should operate, while the other
circuit breakers upstream do not operate, thereby
ensuring that there is minimum area of power supply
which is interrupted.
NOTES
1 Protective devices should have discrimination so that only
the affected part (minimum section) of the circuit is isolated,
even though a number of protective devices may be in the path
of the over current.
2 The electrical network requires the discrimination for all
the fault circuits, including overload, short-circuit, etc. The
downstream device should take care of the fault up to The
level of ultimate short-circuit breaking capacity, 7cU of the
downstream breaker which should be equal to the bus which
is connected.
3 Distinction is made between series discrimination involving
different over-current protective devices passing substantially
the same over-current and network discrimination involving
identical protective devices passing different proportions of the
over -current.
4 Different types of protective devices may have to be used to
ensure effective discrimination in circuits where proper and
effective discrimination is necessary. Apart from the built-in
sensors and actuators in circuit breakers, external relays
operating on different parameters, and comparison of
parameters between two or more points will have to be used for
complex installations.
5 See also relevant parts of the accepted standard [8-2(5)].
2.1. 64 Distance Area or Resistance Area (for an Earth
Electrode Only) — The surface area of ground (around
an earth electrode) on which a significant voltage
gradient may exist.
2.1.65 Diversity Factor — A measure of the probability
that a particular piece of equipment will turn on
coincidentally to another piece of equipment. For
aggregate systems it is defined as the ratio of the sum
of the individual mon-coincident maximum loads of
10
NATIONAL BUILDING CODE OF INDIA 2016
various subdivisions of the system to the maximum
demand of the complete system.
2.1.66 Duct — A closed passage way formed
underground or in a structure and intended to receive
one or more cables which may be drawn in.
2.1.67 Ducting — See 2.1.27.
2.1.68 Earth — The conductive mass of the earth,
whose electric potential at any point is conventionally
taken as zero.
2.1.69 Earth Continuity Conductor — The conductor,
including any clamp, connecting to the earthing lead
or to each other, those parts of an installation which
are required to be earthed. It may be in whole or in
part, the metal conduit or the metal sheath or armour
of the cables, or the special continuity conductor of a
cable or flexible cord incorporating such a conductor.
2.1.70 Earthed Concentric Wiring — A wiring system
in which one or more insulated conductors are
completely surrounded throughout their length by a
conductor, for example a sheath, which acts as a PEN
conductor.
2.1.71 Earth Electrode — A conductor or group of
conductors in intimate contact with the ground to
provide a low resistance path for flow of current to
earth.
2.1.72 Earth Electrode Network — Part of an earthing
arrangement comprising only the earth electrodes and
their interconnections.
2.1.73 Earth Electrode Resistance — The resistance
of an earth electrode to earth.
2.1.74 Earth Fault — An unintended and undesirable
connection of phase/neutral conductor to earth. When
the impedance is negligible, the connection is called a
dead earth fault.
2.1.75 Earth Fault Current — A current- resulting from
a fault of negligible impedance between a line
conductor and an exposed conductive part or a
protective conductor.
2.1.76 Earthing — Connection of the exposed
conductive parts of an installation to the main earthing
terminal of that installation.
2.1.77 Earthing Conductor — A protective conductor
connecting the main earth terminal (or equipotential
bonding conductor of an installation when there is no
earth bus) to an earth electrode or to other means of
earthing.
2.1.78 Earthing Lead — The final conductor by which
the connection to the earth electrode is made.
2.1.79 Earth Leakage Current — A current which flows
to earth, or to extraneous conductive parts, in a circuit
which is electrically sound.
NOTE — This current may have a capacitive component
including that resulting from the deliberate use of
capacitors.
2.1.80 Earthing Resistance, Total — The resistance
between the main earthing terminal and the earth.
2.1.81 Electrical Equipment {abb: Equipment) — Any
item for such purposes as generation, conversion,
transmission, distribution or utilization of electrical
energy, such as machines, transformers, apparatus,
measuring instruments, protective devices, wiring
materials, accessories, and appliances.
2.1.82 Electrically Independent Earth Electrodes —
Earth electrodes located at such a distance from one
another that the maximum current likely to flow through
one of them does not significantly affect the potential
of the other(s).
2.1.83 Electrical Supply System for Life and Safety
Services — A supply system intended to maintain the
operation of essential parts of an electrical installation
and equipment,
a) for health and safety of persons and livestock;
and
b) to avoid damage to the environment and to
other equipment.
NOTES
1 The supply system includes the source and the circuit(s) up
to the terminals of the electrical equipment.
2 See also Part 4 ‘Fire and Life Safety’ of the Code regarding
emergency fire and life safety services.
2.1.84 Electric Shock — A dangerous patho¬
physiological effect resulting from the passing of an
electric current through a human body or an animal.
2.1.85 Emergency Switching — Rapid cutting off of
electrical energy to remove any hazard to persons,
livestock, or property which may occur unexpectedly.
2.1.86 Enclosed Distribution Board — An enclosure
containing bus bars with one or more control and
protected devices for the purpose of protecting,
controlling or connecting more than one outgoing
circuits fed from one or more incoming circuits.
2.1.87 Enclosure — A part providing protection of
equipment against certain external influences and, in
any direction, protection against direct contact.
2.1.88 Equipotential Bonding — Electrical connection
putting various exposed conductive parts and
extraneous conductive parts at a substantially equal
potential.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
11
NOTE — In a building installation equipotential bonding
conductors shall interconnect the following conductive parts:
a) Protective conductor,
b) Earth continuity conductor, and
c) Risers of air conditioning system and heating systems
(if any).
2.1.89 Exposed Conductive Part — A conductive part
of electrical equipment, which can be touched and
which is not normally live, but which may become live
under fault conditions.
2.1.90 Exposed Metal — All metal parts of an
installation which are easily accessible other than,
a) parts separated from live parts by double
insulation;
b) metal name-plates, screw heads, covers, or
plates, which are supported on, or attached,
or connected to substantial non-conducting
material only in such a manner that they do
not become alive in the event of failure of
insulation of live parts and whose means of
fixing do not come in contact with any internal
metal; and
c) parts which are separated from live parts by
other metal parts which are themselves earthed
or have double insulation.
2.1.91 External Influence — Any influence external to
an electrical installation which affects the design and
safe operation of that installation.
2.1.92 Extraneous Conductive Part — A conductive
part not forming part of the electrical installation and
liable to introduce a potential, generally the earth
potential.
2.1.93 Fault — A circuit condition in which current
flows through an abnormal or unintended path. This
may result from an insulation failure or a bridging of
insulation. Conventionally the impedance between live
conductors or between lives conductors and exposed
or extraneous conductive parts at the fault position is
considered negligible.
2.1.94 Fault Current — A current resulting from a fault.
2.1.95 Fault Protection — Protection against electric
shock under single fault conditions.
NOTE — For low voltage installation, system’s and equipment’s
fault protection generally corresponds to protection against
indirect contact, mainly with regards to failure of basic
insulation. Indirect contact is ‘contact of persons or livestock
with exposed-conductive parts which have become live under
fault conditions’.
2.1.96 Final Circuit — A circuit connected directly
to current using equipment, or to socket outlets or
other outlet points for the connection of such
equipment.
2.1.97 Fire Survival Distribution Board — A
distribution board which continues in service after
exposure to fire to the required system rating.
2.1.98 Fitting, Lighting — A device for supporting or
containing a lamp or lamps [for example, fluorescent or
incandescent or halogen or compact fluorescent lamp
(CFL) or light emitting diode (LED)] together with any
holder, shade, or reflector, for example, a bracket, a
pendant with ceiling rose, an electrolier, or a portable unit.
2.1.99 Fixed Equipment — Equipment fastened to a
support or otherwise secured.
2.1.100 Flameproof Enclosure — An enclosure which
will withstand without injury any explosion of
inflammable gas that may occur within it under practical
conditions of operation within the rating of the
apparatus (and recognized overloads, if any, associated
therewith) and will prevent the transmission of flame
which may ignite any inflammable gas that may be
present in the surrounding atmosphere.
NOTES
1 Hazardous areas are classified into different zones, depending
upon the extent to which an explosive atmosphere may exist at
that place. In such areas, flame proof switchgear, fittings,
accessories, have to be used/installed in flameproof enclosure.
2 An electrical apparatus is not considered as flameproof unless
it complies with the appropriate statutory regulations.
3 Other types of fittings are also in vogue in wiring installations,
for example, ‘increased safety’.
2.1.101 Functional Earthing — Connection to earth
necessary for proper functioning of electrical
equipment.
2.1.102 Fuse — A device which, by melting of one or
more of its specially designed and proportioned
components, opens the circuit in which it is inserted by
breaking the current when this exceeds a given value
for a sufficient time. The fuse comprises all the parts
that form the complete device.
2.1.103 Fuse Carrier — The movable part of a fuse
designed to carry a fuse link.
2.1.104 Fuse Element — A part of a fuse designed to
melt when the fuse operates.
2.1.105 Fuse Link — A part of fuse, including the fuse
element(s), which requires replacement by a new or
renewable fuse link after the fuse has operated and
before the fuse is put back into service.
2.1.106 Hand-Held Equipment — Portable equipment
intended to be held in the hand during normal use, in
which the motor, if any, foims an integral part of the
equipment.
NOTE — A hand held equipment is an item of equipment, the
functioning of which requires constant manual support or
guidance.
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NATIONAL BUILDING CODE OF INDIA 2016
2.1.107 Harmonics (Current and Voltage) — All
alternating current which is not absolutely sinusoidal
is made up of a fundamental and a certain number of
current and voltage harmonics [multiples of 50 Hz
(basic frequency)] which are the cause of its
deformation (distortion) when compared to the
theoretical sine-wave.
2.1.108 Hazardous Live Part — A live part which can
give, under certain condition of external influence, an
electric shock.
2.1.109 Impulse Current — A parameter used for the
classification test for SPDs; it is defined by three
elements, a current peak value, a charge Q and a specific
energy W/R.
2.1.110 Impulse Withstand Voltage — The highest peak
value of impulse voltage of prescribed form and polarity
which does not cause breakdown of insulation under
specified condition.
2.1.111 Indirect Contact — Contact of persons or
livestock with exposed conductive parts made live by
a fault and which may result in electric shock.
2.1.112 Industrial Plugs and Sockets — Plugs and
socket-outlets, cable couplers and appliance couplers,
primarily intended for industrial use, either indoors or
outdoors.
NOTE — For the purpose of this Code, industrial plugs and
sockets conforming to 1S/1EC 60309-1:2002 ‘Plugs, socket-
outlets and couplers for industrial purposes — Part 1 : General
requirements’; and 1S/1EC 60309-2:2002 ‘Plugs, socket-outlets
and couplers for industrial purposes — Part 2: Dimensional
Interchangeability Requirements for Pin and Contact Tube
Accessories’ shall be used for industrial purpose.
2.1.113 Inflammable Material — A material capable
of being easily ignited.
2.1.114 Installation (Electrical) — An assembly of
associated electrical equipment to fulfill a specific
purpose or purposes and having coordinated
characteristics.
2.1.115 Insulated — Insulated shall mean separated
from adjacent conducting material or protected from
personal contact by a non-conducting substance or an
air space, in either case offering permanently sufficient
resistance to the passage of current or to disruptive
discharges through or over the surface of the substance
or space, to obviate danger or shock or injurious leakage
of current.
2.1.116 Insulation — Suitable non-conducting material,
enclosing, surrounding or supporting a conductor.
2.1.116.1 Insulation, basic — Insulation applied to live
parts to provide basic protection against electiic shock
and which does not necessarily include insulation used
exclusively for functional purposes.
2.1.116.2 Insulation, double — Insulation comprising
both basic and supplementary insulation.
NOTE — Double insulation for small hand held equipment
allows them to be used without a safety earth connection,
without shock risk such hand held equipment.
2.1.116.3 Insulation, reinforced — Single insulation
applied to live parts, which provides a degree of
protection against electric shock equivalent to double
insulation under the conditions specified in the relevant
standard.
NOTE — The term ‘single insulation’ does not imply that the
insulation is a homogeneous piece. It may comprise several
layers which cannot be tested singly as supplementary or basic
insulation.
2.1.116.4 Insulation, supplementary — Independent
insulation applied in addition to basic insulation in order
to provide protection against electric shock in the event
of a failure of basic insulation.
2.1.117 Isolation — Cutting off an electrical
installation, a circuit, or an item of equipment from
every source of electrical energy.
2.1.118 Isolator — A mechanical switching device
which, in the open position, complies with the
requirements specified for the isolating function. An
isolator is otherwise known as a disconnector.
2.1.119 Junction Box — A box forming a part of- wiring
installation, intended to conceal electrical connections
and joints of conductors/ cables in order to protect the
connection from external influences such as direct
contact, dust, water, moisture, UV radiation, etc,
depending upon the protection requirement of the space
or utility.
2.1.120 LEMP Protection Measures (SPM) —
Measures taken to protect internal systems against the
effects of LEMP.
2.1.121 Lightning Electromagnetic Impulse (LEMP)
All electromagnetic effects of lightning current via
resistive, inductive and capacitive coupling that create
surges and radiated electromagnetic fields.
2.1.122 Lightning Protection — Complete system for
protection of structures aga inst lightning, including their
internal systems and contents, as well as persons, in
general consisting of an LPS and SPM.
2.1.123 Lightning Protection Level (LPL) — A number
related to a set of lightning current parameters values
relevant to the probability that the associated maximum
and minimum design values will not be exceeded in
naturally occurring lightning.
NOTE — Lightning protection level is used to design protection
measures according to the relevant set of lightning cunent
parameters.
PART 8 BUILDING SERVICES - SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
13
2.1.124 Lightning Protection System (LPS) —
Complete system used to reduce physical damage due
to lightning flashes to a structure.
2.1.124.1 External lightning protection system — Part
of the LPS consisting of an air-termination system, a
down-conductor system and an earth-termination
system.
2.1.124.2 Internal lightning protection system — Part
of the LPS consisting of lightning equipotential bonding
and/or electrical insulation of external LPS.
2.1.125 Lightning Protection Zone — Zone where the
lightning electromagnetic environment is defined.
2.1.126 Live or Alive — Electrically charged so as to
have a potential different from that of earth.
2.1.127 Locations, Industrial — Locations where tools
and machinery requiring electrical wiring are installed
for manufacture or repair.
2.1.128 Locations, Non-Industrial — Locations other
than industrial locations, and shall include residences,
offices, shops, showrooms, stores and similar premises
requiring electrical wiring for lighting, or similar
purposes.
2.1.129 Leakage Current — Electric current in an
unwanted conductive path under normal operating
conditions.
2.1.130 Line Conductor — A conductor of an a.c.
system for the transmission of electrical energy other
than a neutral conductor or a PEN conductor. This also
means the equivalent conductor of a d.c. system unless
otherwise specified in this Code.
2.1.131 Live Part — A conductor or conductive part
intended to be energised in normal use including a
neutral conductor but, by convention, not a PEN
conductor.
2.1.132 Low Voltage Switchgear and Controlgear
Assembly — A combination of one or more low voltage
switching devices together with associated control,
measuring, signalling, protective, regulating equipment,
etc, completely assembled under the responsibility of
the manufacturer with all the internal electrical and
mechanical interconnections and structural parts. The
components of the assembly may be electromechanical
or electronic.
2.1.133 Luminaire — Equipment which distributes,
filters or transforms the light from one or more lamps,
and which includes any parts necessary for supporting,
fixing and protecting the lamps, but not the lamps
themselves, and, where necessary, circuit auxiliaries
together with the means for connecting them to the
supply.
NOTE — For the purposes of this Code a batten lampholder,
or a lampholder suspended by flexible cord, is a luminaire.
2.1.134 Main Earthing Terminal — The terminal or
bar which is the equipotential bonding conductor of
protective conductors, and conductors for functional
earthing, if any, to the means of earthing.
2.1.135 Meshed Bonding Network (MESH-BN) —
Bonding network in which all associated equipment
frames, racks and cabinets and usually the d.c. power
return conductor are bonded together as well as at
multiple points to the CBN and may have the form of a
mesh.
2.1.136 Mobile Equipment — Electrical equipment
which is moved while in operation or which can be
easily moved from one place to another while connected
to the supply.
2.1.137 Monitoring — Observation of the operation of
a system or part of a system to verify correct functioning
or detect incorrect functioning by measuring system
variables and comparing the measured value with the
specified value.
2.1.138 Multiple Earthed Neutral System — A system
of earthing in which the parts of an installation specified
to be earthed are connected to the general mass of earth
and, in addition, are connected within the installation
to the neutral conductor of the supply system.
2.1.139 Neutral Conductor — Includes the conductor
of a three-phase four-wire system; the conductor of a
single-phase or d.c. installation, which is earthed by
the supply undertaking (or otherwise at the source of
the supply), and the middle wire or common return
conductor of a three-wire d.c. or single-phase a.c.
system.
2.1.140 Origin of an Electrical Installation — The
point at which electrical energy is delivered to an
installation.
NOTE — An electrical installation may have more than one
origin.
2.1.141 Overcurrent — A current exceeding the rated
value. For conductors the rated value is the current
carrying capacity.
2.1.142 Overload Current (of a Circuit) — An
overcurrent occurring in a circuit in the absence of an
electrical fault.
2.1.143 PEN Conductor — A conductor combining the
functions of both protective conductor and neutral
conductor.
2.1.144 Phase Conductor — See 2.1.130.
2.1.145 Plug — A device, provided with contact pins,
which is intended to be attached to a flexible cable.
14
NATIONAL BUILDING CODE OF INDIA 2016
and which can be engaged with a socket outlet or with
a connector.
2.1 .146 Point (in Wiring) — A termination of the fixed
wiring intended for the connection of current using
equipment.
2.1.147 Portable Equipment — Equipment which is
moved while in operation or which can easily be moved
from one place to another while connected to the supply.
2.1.148 Protection, Ingress — The degree of protection
against intrusions (body parts such as hands and
fingers), dust, accidental contact and water.
NOTE — The classification of degrees of ingress protection
provided by enclosures for electrical equipment shall be as per
the accepted standard [8-2(6)].
2.1.149 Protection, Mechanical Impact — The degrees
of protection provided by enclosures for electrical
equipment against external mechanical impacts.
NOTE — The classification of degrees of protection against
mechanical impact provided by enclosures for electrical
equipment shall be as per IEC 62262:2002 ‘Degrees of
protection provided by enclosures for electrical equipment
against external mechanical impacts (IK code)’.
2.1.150 Prospective Fault Current (7pf) — The value
of overcurrent at a given point in a circuit resulting
from a fault of negligible impedance between live
conductor having a difference of potential under normal
operating conditions, or between a live conductor and
an exposed-conductive part.
2.1.151 Protective Conductor — A conductor used for
some measures of protection against electric shock and
intended for connecting together any of the following
parts:
a) Exposed conductive parts,
b) Extraneous conductive parts,
c) Main earthing terminal, and
d) Earthed point of the source, or an artificial
neutral.
2.1.152 Protective Conductor Current — Electric
current appearing in a protective conductor, such as
leakage current or electric current resulting from an
insulation fault.
2.1.153 Protective Earthing — Earthing of a point or
points in a system or in equivalent for the purpose of
safety.
2.1.154 Protective Separation — Separation of one
electric circuit from another by means of,
a) double insulation;
b) basic insulation and electrically protective
screening (shielding); or
c) reinforced insulaiion.
2.1.155 Rated Current — Value of current used for
specification puq?oses, established for a specified set
of operating conditions of a component, device,
equipment or system.
2.1.156 Rated Impulse Withstand Voltage Level (C/w) —
The level of impulse withstand voltage assigned by the
manufacturer to the equipment, or to part of it,
characterizing the specified withstand capability of its
insulation against overvoltage.
2.1.157 Residual Current — The algebraic sum of the
instantaneous values of current flowing through all live
conductors of a circuit at a point of the electrical
installation.
2.1.158 Residual Current Device (RCD) — A
mechanical switching device or association of devices
intended to cause the opening of the contacts when the
residual current attains a given value under specified
conditions.
2.1.159 Residual Operating Current — Residual
current which causes the residual current device to
operate under specified conditions.
2.1.160 Service — The conductors and equipment
required for delivering energy from the electric supply
system to the wiring system of the premises served.
2.1.161 Shock Current A current passing through the
body of a person or an animal and having characteristics
likely to cause dangerous patho-physiological effects.
2.1.162 Short-Circuit Current — An overcurrent
resulting from a fault of negligible impedance between
live conductors having a difference in potential under
normal operating conditions.
2.1.163 Space Factor — The ratio (expressed as a
percentage) of the sum of the overall cross-sectional
areas of cables (including insulation and sheath) to the
internal cross-sectional area of the conduit or other
cable enclosure in which they are installed. The
effective overall cross-sectional area of a non-circular
cable is taken as that of a circle of diameter equal to
the major axis of the cable.
2.1.164 Standby Supply System — A system intended
to maintain supply to the installation or part thereof, in
case of interruption of the normal supply, for reasons
other than safety of persons.
NOTE — Standby supplies are necessary, for example, to avoid
interruption of continuous industrial processes or data
processing.
2.1.165 Stationary Equipment — Either fixed
equipment or equipment not provided with a carrying
handle and having such a mass that it cannot easily be
moved.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
15
2.1.166 Step Voltage — The potential difference
between two points on the earth’s surface, separated
by distance of one pace, that will be assumed to be one
metre in the direction of maximum potential gradient.
2.1.167 Socket-Outlet — A device, provided with
female contacts, which is intended to be installed with
the fixed wiring, and intended to receive a plug.
NOTE — A luminaire track system is not regarded as a socket-
outlet system.
2.1.168 Surge — A transient created by LEMP that
appears as an overvoltage and/or an overcurrent.
2.1.169 Surge Protective Devices ( SPD ) — A device
intended to limit transient overvoltages and divert surge
currents. It contains at least one non-linear component.
2.1.170 Switch — A mechanical switching device
capable of making, carrying and breaking current under
normal circuit conditions, which may include specified
operating overload conditions; and also of carrying for
a specified time currents under specified abnormal
circuit conditions, such as those of short circuit.
NOTE — A switch may also be capable of making, but not
breaking, short-circuit currents.
2.1.171 Switchboard — An assembly of switchgear
with or without instruments, but the term does not apply
to a group of local switches in a final circuit.
NOTE — The term ‘switchboard’ includes a distribution board.
2.1.172 Switch Disconnector — A switch which, in the
open position, satisfies the isolating requirements
specified for a disconnector.
NOTE — A switch disconnector is otherwise known as an
isolating switch.
2.1.1 73 Switch Disconnector Fuse — A composite unit,
comprising a switch with the fuse contained in or
mounted on the moving member of the switch.
2.1.174 Switch, Linked — A switch, the contacts of
which are so arranged as to make or break all poles
simultaneously or in a definite sequence.
2.1.175 Switchgear — An assembly of main and
auxiliary switching apparatus for operation, regulation,
protection or other control of electrical installations.
2.1.176 System ( Electrial ) — An electrical system
consisting of a single source or multiple sources running
in parallel of electrical energy and an installation. Types
of system are identified as follows, depending upon
the relationship of the source, and of exposed-
conductive parts of the installation, to earth:
a) TN system — A system having one or more
points of the source of energy directly earthed,
the exposed conductive-parts of the
installation being connected to that point by
protective conductors.
b) TN-C system — A system in which neutral and
protective conductors are combined in a single
conductor throughout the system.
c) TN-S system — A system having separate
neutral and protective conductor throughout
the system.
d) TN-C-S system — A system in which neutral
and protective conductors are combined in a
single conductor in part of the system.
e) TT system — A system having one point of
the source of energy directly earthed, the
exposed-conductive -parts of the installation
being connected to the earth electrodes
electrically independent of the earth electrodes
of the source.
f) IT system — A system having no direct
connection between live parts and earth, the
exposed-conductive-parts of the electrical
installation being earthed.
2.1.177 Touch Voltage — The potential difference
between the ground potential rise (GPR) of a grounded
metallic structure and the surface potential at the point
where a person could be standing while at the same
time having a hand in contact with the grounded metallic
structure. Touch voltage measurements can be ‘open
circuit’ (without the equivalent body resistance included
in the measurement circuit) or ‘closed circuit’ (with the
equivalent body resistance included in the measurement
circuit) voltage by which an installation or part of an
installation is designated.
2.1.178 Usable Wall Space — All portions of a wall,
except that occupied by a door in its normal open
position, or occupied by a fire place opening, but
excluding wall spaces which are less than 1 m in extent
measured along the wall at the floor line.
2.1.179 Utility Building — A standalone separate single
or two storied service building structure outside the
main building structure meant for only accommodating
services’ spaces, such as electric substation, diesel
generator plant room, a.c. plant room, plumbing plant
room, sewerage treatment plant, medical gases,
electrical and mechanical maintenance rooms. Such
buildings do not have any permanent occupancy other
than by personnel on duty.
2.1.180 Voltage, Nominal (of an Installation) —
Voltage by which an installation or part of an installation
is designated.
2.1.181 Voltage, Extra Low (ELV) — The voltage which
does not normally exceed 50 V.
2.1.182 Voltage, Low (LV) — The voltage which
normally exceeds 50 V but does not normally exceed
250 V.
16
NATIONAL BUILDING CODE OF INDIA 2016
2.1.183 Voltage, Medium (MV) — The voltage which
normally exceeds 250 V but does not exceed 650 V.
2.1.184 Voltage, High (HV) — The voltage which
normally exceeds 650 V but less than or equal to 33 kV.
2.1.185 Voltage, Extra High (EHV) — The voltage,
which normally exceeds 33 kV.
2.1.186 Weatherproof — Accessories, lighting fittings,
current-using appliances and cables are said to be of
the weatherproof type with ingress protection according
to the application, if they are so constructed that when
installed in open situation they will withstand the effects
of rain, snow, dust and temperature variations.
2.2 Conventional Symbols
The architectural symbols that are to be used in all
drawings, wiring plans, etc, for electrical installations
in buildings shall be as given in Annex A.
For other graphical symbols used in electrotechnology,
reference may be made to good practice [8-2(1)].
3 GENERAL REQUIREMENTS
3.1 Conformity with The Electricity Act, 2003 and
Central Electricity Authority (Measures Relating to
Safety and Electric Supply) Regulations , 2010 as
Amended Up-to-Date
The installation shall generally be carried out in
conformity with the requirements of The Electricity Act ,
2003 as amended up-to-date and the Central Electricity
Authority (Measures Relating to Safety and Electric
Supply) Regulations, 2010 framed thereunder and as
amended from time-to-time; and also the relevant
regulations of the Electric Supply Authority concerned
as amended from time-to-time. Extracts from the
Central Electricity Authority (Measures Relating to
Safety and Electric Supply) Regulations, 2010 (as
amended in 2015), referred to in this Section, are given
in Annex B.
3.2 Materials
All materials, fittings, appliances, etc, used in electrical
and allied installations, shall conform to Part 5
‘Building Materials’ of the Code and other concerned
Indian Standards.
3.3 Coordination with Local Supply Authority
a) In all cases, that is, whether the proposed
electrical work is a new installation or
extension of an existing one, or a modification
involving major changes, the electricity supply
undertaking shall be consulted about the
feasibility, etc, at an early date. The wattage
per square metre and permissible diversity
consideration shall be defined as per the type
of building (residential, commercial,
mercantile, industrial, retail, convention,
exhibition, hotel, hospital, institution, flatted
factory, group housing, etc). The wattage per
square feet shall be defined considering
probable loads as per city grading such that
future loading into the development is
accounted.
b) Addition to an Installation — An addition,
temporary or permanent, shall not be made to
the authorized load of an existing installation,
until it has been definitely ascertained that the
current carrying capacity and the condition of
existing accessories, conductors, switches, etc,
affected, including those of the supply
authority are adequate for the increased load.
The size of the cable/conductor shall be
suitably selected on the basis of the ratings of
the protective devices. Ratings of protective
devices and their types shall be based on the
installed load, switching characteristics and
power factor.
Load assessment and application of suitable diversity
factor to estimate the full load current shall be made as
a first step. This should be done for every circuit,
submain and feeder. Power factor, harmonics
(see 5.3.6. 6) and efficiency of loads shall also be
considered. Diversity factor assumed shall be based
on one’s own experience or as per table under 4.2. 2.2.
Allowance should be made for about 1 5 percent to 20
percent for extension in near future. The wiring system
should be adopted taking into account the
environmental requirements and hazards, if any in the
building. The sizes of wiring cables are decided not
merely to carry the load currents, but also to withstand
thermal effects of likely overcurrents, short circuit and
also to ensure acceptance level of voltage drop.
3.4 Power Factor Improvement in Consumers’
Installation
3.4.1 Conditions of supply of electricity boards or
licensees stipulate the lower limit of power factor which
is generally 0.90 or better.
3.4.2 Principal causes of low power factor are many.
For guidance to the consumers of electric energy who
take supply at low and medium voltages for
improvement of power factor, reference shall be made
to good practice [8-2(7)].
3.5 Execution of Work
Unless otherwise exempted under the appropriate
regulation of the CEA (Measures relating to Safety and
Electricity Supply) Regulations, 201 0 as amended from
time-to-time, the work of electrical installations shall
be carried out by a licensed electrical contractor and
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
17
under the direct supervision of a person holding a
certificate of competency and by persons holding a valid
permit issued and recognized by any State government.
3.6 Safety procedures and practices shall be kept in view
during execution of the work in accordance with good
practice [8-2(8)].
3.7 Safety provisions given in Part 4 ‘Fire and Life
Safety’ of the Code shall be followed.
4 PLANNING OF ELECTRICAL INSTALLA¬
TIONS
4.1 General
The design and planning of an electrical wiring
installation involve consideration of all prevailing
conditions, and is usually influenced by the type and
requirements of the consumer. Various utility services
including LV systems namely intercom, data cabling {see
Part 8 ‘Building Services, Section 6 Information and
Communication Enabled Installations’ of the Code),
CCTV, fire alarm shall also be taken into account with
anticipated future requirements. A competent electrical
design engineer should be involved at the planning stage
with a view to providing for an installation that will prove
adequate for its intended purpose and ensure safety,
reliability and energy efficiency in its use. The
information/requirements given in 3 shall also be kept
into consideration while designing and planning an
electrical wiring installation. With the proliferation of
the use of electrical and electronic devices in buildings
as well as the increase in the generation/distribution
capacities of power systems, the hazards of energy feed
to a fault or defect in the electrical installation have
increased. Reliability of power supply and continued
supply even under abnormal conditions are becoming
very important not only for the operation of services and
activities in a building, but also for the life safety of
occupants. Reference is drawn to Part 0 ‘Integrated
Approach — Prerequisite for Applying Provisions of the
Code’ of the Code, which defines the requirements of
interdisciplinary coordination right from the sketch
design of the building. Electricity is linked to all services
and addition of standby and emergency power supply
systems adds to the complexity, thus requiring proper
coordinated design. Generally it is not difficult to provide
proper pathways and equipment installation spaces, if
an integrated approach is taken from the beginning. The
designs should also have to keep the availability of
optimum access to installations to ensure proper
maintenance. Considering various utility services and
to avoid conflict amongst them, it is most important to
estimate space requirement for electrical work including
LV systems, at planning stage and allocate it in
consultation with an architect/civil engineer.
4.1.1 The design and planning of an electrical wiring
installation shall take into consideration the following:
a) Type of supply, building utility, occupancy,
envisaged load and the earthing arrangement
available;
b) Provisioning of air conditioning systems in
present and/or future loading;
c) Climatic condition, such as cooling air
temperature, moisture or such other conditions
which are likely to affect the installation
adversely;
d) Possible presence of inflammable or explosive
dust, vapour or gas;
e) Degree of electrical and mechanical protection
necessary;
f) Importance of continuity of service including
the possible need for standby supply;
g) Probability of need for modification or future
extension;
h) Probable operation and maintenance cost
taking into account the electricity supply tariffs
available;
j) Relative cost of various alternative methods;
k) Need for radio and telecommunication
interference suppression;
m) Ease of maintenance;
n) Safety aspects;
p) Energy conservation;
q) Importance of proper discrimination between
protective devices for continuity of supply and
limited isolation of only the affected portion;
and
r) Reliability of power supply and redundancy (of
sources and distribution paths) to cater to the
needs for emergency power and standby power
for continued operation of systems as well as
integration of alternate sources of energy such
as diesel generation, solar energy, wind power,
etc.
4.1.2 All electrical apparatus shall be suitable for the
services these are intended for.
4.1.3 Coordination
Proper coordination and collaboration between the
architect, civil engineer, electrical engineer and
mechanical engineer shall be effected from the planning
stage of the installation. The electrical engineer shall
be conversant with the needs of the electrical supply
provider for making electrical supply arrangement.
Electrical supplier’s installation, as per Regulations,
needs to be segregated from consumer’s installation.
Wherever required, prior approval of drawings shall
be taken from concerned electrical supplier/electrical
inspector. Further, depending on load and regulation
18
NATIONAL BUILDING CODE OF INDIA 2016
provisions, consumer will need to submit to the
electrical supplier the details regarding the
accommodation of substation including transformers,
switch-rooms, standby power, solar photovoltaic
panels, lightning scheme for the approval. Additional
information may be sought by the Authority regarding
cable ducts, rising mains and distribution cables, sub¬
distribution boards, openings and chases in floors and
walls for all required electrical installations, etc.
4.1.4 Before starting wiring and installation of fittings
and accessories, information should be exchanged
between the owner of the building/architect/ consultant/
electrical contractor and the local supply authority in
respect of tariffs applicable, types of apparatus that may
be connected under each tariff, requirement of space
for installing meters, switches, etc, and for total load
requirements of lights, fans and power.
4.1.5 While planning an installation, consideration
should be taken of the anticipated increase in the use of
electricity for lighting, general purpose socket-outlet,
kitchen equipment, air conditioning, utility sockets,
heating, etc.
It is essential that adequate provision should be made
for all the services which may be required immediately
and during the intended useful life of the building, for
the householder, who may otherwise be tempted to carry
out extension of the installation himself or to rely upon
use of multi-plug adaptors and long flexible cords, both
of which are not recommended.
4.2 Substation and Switchrooms
4.2.1 Location and Other Requirements
The location and other requirements of a substation and
switchrooms shall be as given below:
1 ) Availability of power lines nearby may be kept
in view while deciding the location of the
substation.
2) The substation should preferably be located in
a separate utility building and may be adjacent
to the generator room, if any. Location of
substation in the basement should be avoided,
as far as possible.
3) In case there is only one basement in a
building, the substation/switchroom shall not
be provided in the basement. Also, the floor
level of the substation shall not be lowest point
of the basement.
4) Ideal location for an electrical substation for a
group of buildings will be at the electrical load
centre. Generally the load centre will be
somewhere between the geometrical centre and
the air conditioning plant room, as air
conditioning plant room will normally be the
largest load, if the building(s) are centrally air
conditioned.
5) In order to prevent storm water entering the
transfonuer and switch rooms through the soak-
pits, the floor level of the substation/
switchroom shall be at least 300 mm above the
highest flood water level that may be
anticipated in the locality. Also, facility shall
be provided for automatic removal of water.
6) Substation shall not be located immediately
above or below plumbing water tanks or sewage
treatment plant (STP) water tanks at the same
location.
7) All door openings from substation, electrical
rooms, etc, should open outwards. Vertical
shutters (like fire rated rolling shutters) may
also be acceptable provided they are combined
with a single leaf door opening outwards for
exit in case of emergency. For large substation
room/electrical room having multiple
equipment, two or more doors shall be
provided which shall be remotely located from
each other.
8) If substation is located at a height 1 000 m
above MSL, then adequate derating of
equipment shall be considered.
9) In case of HV panel and transformers located
at different floors or at a distance more than
20 m, HV isolator shall be provided at
transformer end.
10) In case transformer and main MV/LV panel
room are located at different floors or are at a
distance more than 20 m, MV/LV isolator shall
be provided at transformer end. In case
transformer and main MV/LV panel room are
located at different floors, the designer should
also take care of the safety requirements caused
by lack of direct visibility of the staUis of the
controlling switch. To cater to the safety
requirements under different conditions of
operation as well as maintenance, it may be
necessary to provide additional isolator or an
emergency push button in the vicinity to trip
the supply. Decision has to be taken based on
the possible risks.
11) No services or ventilation shafts shall open into
substation or switch room unless specific to
substation or switch room.
12) Oil-filled installation — Substations with oil-
filled equipment require great consideration
for the fire detection, protection and
suppression. Oil-filled transformers require a
suitable soak pit with gravity flow to contain
the oil in the event of the possibility of oil
spillage from the transformer on its failure.
Installation of oil-filled equipment shall meet
the following requirements:
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
19
i) Substations with oil-filled equipment/
apparatus [transformers and high voltage
panels] shall be either located in open or
in a utility building. They shall not be
located in any floor other than the ground
floor or the first basement of a utility
building. They shall not be located below
first basement slab of utility building.
They shall have direct access from
outside the building for operation and
maintenance of the equipment.
ii) Substations/Utility buildings (where the
substation or oil-filled transformer is
located) shall be separated from the
adjoining buildings including the main
building by at least 6 m clear distance to
allow passage of fire tender between the
substation/utility building and adjoining
building/main building.
iii) There shall be no interconnecting
basement with the main building
underneath the oil-filled transformers.
iv) Provisions for oil drainage to a point at a
lower level and separated by adequate fire
barrier shall be provided. If there is a floor
directly below the ground floor level or
first basement where the oil-filled
transformers and oil-filled circuit breakers
are placed, then they shall be separated by
a fire barrier of appropriate fire rating as
per Part 4 ‘Fire and Life Safety’ of the
Code and proper oil drainage system shall
be provided to avoid possible leakage of
oil into the lower floor.
v) Substation equipment having more than
2 000 litre of oil whether located indoors
in the utility building or outdoors shall
have baffle walls of 4 h fire rating
between apparatus ( see also Part 4 ‘Fire
and Life Safety’ of the Code for fire safety
related requirements).
vi) Provisions shall be made for suitable oil
soak-pit, and where use of more than 9 000
litre of oil in any one oil tank, receptacle
or chamber is involved, provision shall be
made for the draining away or removal of
any oil which may leak or escape from the
tank, receptacle or chamber containing the
same. Special precautions shall be taken
to prevent the spread of any fire resulting
from the ignition of the oil from any cause
and adequate provision shall be made for
extinguishing any fire which may occur.
vii) In respect of all oil type transformers
located at basement, a kerb (sill) of a
suitable height shall be provided at the
entrance in order to prevent the flow of oil
from a ruptured transformer into other
parts of the basement in the event of the
possibility of oil spillage from the
transformer on its failure.
viii) Adequate fire barriers or deflectors shall
be provided to avoid flames from the
substation reaching or affecting the upper
floors ( see also Part 4 ‘Fire and Life Safety’
of the Code).
ix) For transformers having large oil content
(more than 2 000 litre), Rule 44(2) of the
Central Electricity Authority (Measures
Relating to Safety and Electric Supply)
Regulations , 20 1 0 as amended from time-
to-time shall apply ( see Annex B).
13) Dry-type installation — In case electric
substation has to be located within the main
multi-storeyed building itself for unavoidable
reasons, it shall be a dry-type installation with
very little combustible material, such as, a dry
type transformer with vacuum (or SF6) breakers
as HT switchgear and ACB or MCCB as
medium voltage (MV) switchgear. Such
substations shall be located on the ground level
or on first basement, and shall have direct
access from the outside of the building for
operation and maintenance of the equipment.
Exceptionally, in case of functional buildings,
such as air traffic control towers, data centres
and buildings of height more than 1 00 m having
high electrical load requirement, dry-type
installations/substations may also be provided
at upper level. This measure will decrease the
current flow and short-circuit rating at various
points, thereby reducing vulnerability to fire.
In such cases, a base substation shall be located
at ground floor/first basement to cater to the
main MV/LV panel which feeds life and safety
services loads as defined in 4.2.1 (29). The base
substation shall be located in such a way to
provide direct access to the firemen in case of
any emergency. The power supply control to
any substation or transformer located at upper
floors shall be from the base substation so that
in case of fire, the electrical supply can be easily
disconnected to avoid additional losses.
14) The power supply HV cables voltage shall not
be more than 1 2 kV and a separate dedicated
and fire compartmented shaft should be
provided for carrying such high voltage cables
to upper floors in a building. These shall not
be mixed with any other shaft and suitable fire
detection and suppression measures shall be
provided throughout the length of the cable on
20
NATIONAL BUILDING CODE OF INDIA 2016
each floor.
15) The provision for installation and removal of
substation equipment should be provided from
inside or outside the building without disturbing
the associated major equipment in the substation.
16) In case of compact substation {see accepted
standard [8-2(4)]}, design and location of the
substation shall ensure safety of the people
around the compact substation installed along
walkways, playgrounds, etc. Compact
substation with incomer voltage of 12 kV or
less, when located in open areas shall have
fencing or barrier (of any metal based
protection, such as wire mesh or chain link,
which is duly earthed) against unauthorized
contact possibility around it at a minimum
distance of 750 mm around it with access for
maintenance from all four sides. For incomer
voltage more than 1 2 k V and less than 24 kV
the fencing distance from substation may
be 1 000 mm minimum. In case of more than
24 kV incomer, the distance may be further
increased accordingly. The fencing design
should take care of the servicing and
maintenance requirements of the substation
equipment.
17) In case of two transformers (dry type or
transformers with oil quantity less than 2 000
litre) located next to each other without
intermittent wall, the distance between the two
shall be minimum 1 500 mm for 11 kV,
minimum 2 000 mm for 22 kV and minimum
2 500 mm for 33 kV. Beyond 33 kV, two
transformers shall be separated by baffle wall
of 4 h fire rating.
18) Horizontal routing of HT cable through
fiinctional/occupied areas should be avoided
in view of safety.
1 9) If dry type transformer is used, it may be located
adjacent to medium voltage switchgear in the
form of unit type substation. In such a case, no
separate room or fire barrier for the transformer
is required either between transformers or
between transformer and the switchgear,
thereby decreasing the room space requirement;
however, minimum distances as specified
in 4.2.1 (17) shall be maintained between the
apparatus depending upon voltage ratings.
Layout of equipment should take care of the
need that any one piece of equipment or sub-
assembly can be taken out of service and out
of the installed location, while keeping the
remaining system in service. Working space for
access for maintenance of equipment, while
keeping an adjoining section of the substation
live to maintain power supply to essential loads,
may require additional space between such
sections of equipment.
20) In places where flooding can occur and water
level may go above 1 000 mm, the base
substation may be located on one level above
the ground level of a utility building. In such
cases, one feeder should feed ground level and
levels below with automatic tripping of the
feeder to avoid electrocution in case of live
electricity coming in contact with water.
Designers shall use their discretion in special
cases and depending on the degree of reliability,
redundancy and the categoiy of load and make
suitable provisions.
NOTE — In cases, where the substation is located
one level above ground level of utility building, this
should be after due evaluation of the other risks posed
by such a location combined with the concurrence
for such a decision from State Electricity Authority
comprising the electrical inspectorate and the
distribution licensee and the fire service.
21 ) For acoustical enclosures/treatment, reference
may be made to Part 8 ‘Building Services’,
Section 4 ‘Acoustics, Sound Insulation and
Noise Control’ of the Code.
22) The minimum recommended spacing between
the walls and the transformer periphery from
the point of proper ventilation shall be in
accordance with good practice [8-2(9)] ( see
also Fig. 1A). The actual spacing may be
different than those given in the figure,
depending on the circumstances, such as access
to the accessories. Other requirements relating
to installation of transformers shall also be in
accordance with good practice [8-2(9)].
23 ) High voltage switch room/space — The design
should take care of HV equipment space and
clearance required around for maintenance and
personnel safety as given in 5.3.6.8. This room
may preferably have direct access from outside.
In case of substation having one transformer
and one source of supply, the owner shall
provide one high voltage switch. In case of
single point supply with two or more
transformers, the number of switch required
will be one for incoming supply and one for
each transformer. Additional space may be
provided keeping in mind future requirement,
if any. In case of duplicate supply, two switches
shall be provided with mechanical/electrical
inter locking arrangement. In case the number
of incoming and outgoing switches exceed five,
bus coupler of suitable capacity should
invariably be provided.
24) Medium voltage switch room/space — The floor
area required in respect of medium voltage
switchgear room may be determined keeping in
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
21
view the number and type of incoming/outgoing
bus coupler switches including likely expansion
in future and space requirement as given in
53.6.8. The additional requirements of MV
switchroom when located separate from the
substation shall be as per 4.2.4.
25) Other requirements relating to installation of
switchgears and controlgears as given in good
practice [8-2(10)] shall also be complied with.
26) The minimum height of substation room/HV
switch room/MV switch room shall be arrived
at considering 1 200 mm clearance
requirement from top of the equipment to the
below of the soffit of the beam (see also
Annex C). In case cable entry/exit is from
above the equipment (transformer, HV
switchgear, MV switchgear), height of
substation room/HV switch room/MV switch
room shall also take into account requirement
of space for turning radius of cable above the
equipment height.
27) All the rooms shall be provided with partitions
up to the ceiling and shall have proper
ventilation. Special care should be taken to
dissipate transformer heat and where
necessary fresh air louvers at lower level and
exhaust fans at higher level shall be provided
at suitable locations.
28) In case of cable trench in substation/HV switch
room/MV switch room, the same shall be
adequately drained to ensure no water is
stagnated at any time with live cables.
29) Power supply to emergency fire and life safety
systems — Emergency power supplying
distribution system for critical requirement for
functioning of fire and life safety system and
equipment, shall be planned for efficient and
reliable power and control supply to the
following systems and equipment where
provided:
i) Fire pumps;
ii) Pressurization and smoke venting;
including its ancillary systems such as
dampers and actuators;
iii) Fireman’s lifts (including all lifts).
iv) Exit signage lighting;
v) Emergency lighting;
vi) Fire alarm system;
vii) Public address (PA) system (relating to
emergency voice evacuation and
annunciation);
viii) Magnetic door hold open devices; and
ix) Lighting in fire command centre and
security room.
Power supply to these systems and equipment
shall be from normal and emergency (standby
generator) power sources with change over
facility. It shall be ensured that in case the power
supply is from HT source/HT generation,
transformers should be planned in stand-by
capacity to ensure continuity of power to such
systems. Wherever transformers are installed
at higher levels in buildings and backup DG
sets are of higher voltage rating, then dual
redundant cables shall be taken to all
transformers. The generator shall be capable
of taking starting current of all the fire and life
safety systems and equipment as above. Where
parallel HV/LV supply from a separate
substation fed from different grid is provided
with appropriate transformer for emergency, the
provision of generator may be waived in
consultation with the Authority.
The power supply to the panel/distribution
board of these fire and life safety systems shall
be through fire proof enclosures or circuit
integrity cables or through alternate route in
the adjoining fire compartment to ensure that
supply of power is reliable to these systems and
equipment. It is to be ensured that the cabling
from the adjoining fire compartment is to be
protected within the compartment of
vulnerability. The location of the panel/
distribution board feeding the fire and life safety
system shall be in fire safe zone ensuring supply
of power to these systems.
Cables for fire alarm and PA system shall be
laid in metal conduits or armoured to provide
physical segregation from the power cables.
30) Other requirements as given in Central
Electricity Authority (Measures relating to
Safety and Electricity > Supply) Regulations ,
2010 as amended shall also be complied with.
The fire safety requirements for substation and
electrical rooms, including fire rating
requirements of substations enclosure, that is,
walls, floor, ceiling, openings, doors, etc, as
given in Part 4 ‘Fire and Life Safety’ of the
Code shall also be complied with.
4.2.2 Layout of Substation
4.2.2. 1 In allocating the area of substation, it is to be
noted that the flow of electric power is from supply
company s meter room to HV room, then to transformer
and finally to the MV switchgear room. The layout of
the room and trenches of required depth shall be in
accordance with this flow, so as to optimize the cables,
bus-trunking, etc. Visibility of equipment controlled from
the operating point of the controlling switchgear is also
a desirable feature, though it may not be achievable in
case of large substations. Substations shall not be located
22
NATIONAL BUILDING CODE OF INDIA 2016
at or across expansion joints. The rooms/spaces required
in a substation shall be provided as given below:
a) Supply company s meter room , generally at the
periphery of the premise with direct access from
the road/outside;
b) HV isolation room , required in case the
substation is away from the meter room and is
planned adjacent to meter room for
disconnecting supply in case of any repair
required between meter room and substation;
c) HV panel room/space, located adjacent to
transformer;
d) Transformer room/space, separate space in case
of oil-filled transformer and combined space
in case of dry type transformer;
e) MV isolation room/space, required in case MV
panel is away from transformer or on a different
level for isolating supply in case of any repair
required between transformer and MV
switchgear; and
f) Main MV panel room/space , required for
distribution to different facility/utility in a
building.
A typical layout of a substation is shown in Fig. IB.
4.2.2.2 Capacity and size of substation
The capacity of a substation depends upon the area of
the building and its type. The capacity of substation may
be determined based on the load requirements ( see
also 3.3). Ratings of electrical equipment as given in
6.1, may be assumed, unless the values are known or
specified and diversity requirements as given below may
be used for load assessment:
SI Purpose of Final Circuit Fed
No. from Conductors or
Typical Allowances for Diversity Based on:
Type of Building
Switchgear to which
-
- - -
- ^
Diversity Applies
Individual House Hold
Small Shops,
Small Hotels,
Installations, Including
Stores, Offices and
Boarding Houses,
Individual Dwelling
Business
etc
of a Block
Premises
(1)
(2)
(3)
(4)
(5)
i)
Lighting
66 percent of total current
90 percent of total
75 percent of total
demand
current demand
current demand
ii)
Heating and power [ see also
100 percent of total
100 percent of full
100 percent of full
SI No. (iii) to (iv)]
current demand up to
load of largest
load of largest
10 A
appliance
appliance
+ 50 percent of any
+ 75 percent of
+ 80 percent of
current demand in excess
remaining
second largest
of 10 A
appliances
appliance +
60 percent of
remaining
appliances
iii)
Cooking appliances
10 A +
100 percent of full
100 percent of full
30 percent full load of
load of largest
load of largest
connected cooking
appliance
appliance
appliances in excess of
+ 80 percent of
+ 80 percent of
10 A
full load of second
full load of second
+ 6 A if socket-outlet
largest appliance
largest appliance
incorporated in the unit
+ 60 percent of
+ 60 percent of
full load of
full load of
remaining
remaining
appliances
appliances
iv)
Motors (other than lift
100 percent of full
100 percent of full
motors which are subject to
load of largest
load of largest
special consideration)
motor
motor
+ 80 percent of
+ 50 percent of
full load of second
full load of
largest motor
remaining motors
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
23
SI Purpose of Final Circuit Fed
No. from Conductors or
Switchgear to which Diversity
Applies
(1) (2)
Typical Allowances for Diversity Based on:
Type of Building
v) Water heater [instantaneous
type0]
Individual House Hold
Installations, Including
Individual Dwelling
of a Block
(3)
Small Shops,
Stores, Offices
and Business
Premises
(4)
Small Hotels,
Boarding Houses,
etc
(5)
+ 60 percent of
full load of
remaining motors
1 00 percent of full
1 00 percent of
1 00 percent of full
load of largest
full load of
load of largest
appliance
largest appliance
appliance
+ 100 percent of full
+ 1 00 percent of
+ 1 00 percent of full
load of second largest
full load of
load of second largest
appliance
second largest
appliance
+ 25 percent of full
appliance
+ 25 percent of full
load of remaining
+ 25 percent of
load of remaining
appliances
full load of
remaining
appliances
appliances
vi) Water heater (thermostatically No diversity
controlled) allowable0
vii) Floor warming installations
No diversity
allowable0
viii) Water heaters thermal storage
space heating installations
ix) Standard arrangements of final
circuits in accordance with
good practice [8-2(1 1)]
No diversity
allowable0
100 percent of the
current demand of the
largest circuit
+ 40 percent of the
current demand of
every other circuit
100 percent of
the current
demand of the
largest circuit
+ 50 percent of
the current
demand of every
other circuit
Socket outlets other than those
included in SI No. (ix) and
stationary equipment other
than those listed above
100 percent of the
current demand of the
largest point
+ 40 percent of the
current demand of
every other point
x) Socket outlets other than those 1 00 percent of the 1 00 percent of 1 00 percent of the
current demand of the
largest point
+ 75 percent of the
current demand of
every point in main
rooms (dining rooms,
etc)
+ 40 percent of the
current demand of
every other point
NOTE — Diversity may be considered , if multiple units of water he ater are there in an individual house -hold installation, including
individual dwelling of a block
100 percent of
the current
demand of the
largest point
+ 75 percent of
the current
demand of every
other point
For the purpose of the table, an instantaneous water heater is deemed to be a water heater of any loading which heats water only
while the tap is turned o n and therefore uses electricity intermittently.
2) It is important to ensure that the distribution boards are of sufficient rating to take the total load connected to them without the
application of any diversity.
24
NATIONAL BUILDING CODE OF INDIA 2016
After calculating the electrical load on the above basis,
an overall load factor of 70 to 90 percent is to be applied
to arrive at the minimum capacity of substation. A future
load may also be considered for substation sizing
( see 3.3). The area required for substation and
transformer room for different capacities is given in
Annex C for general guidance. For reliability, it is
recommended to split the load into more than one
transformer and also provide for standby transformer
as well as multiple sources, bus-section, etc.
4.3 Emergency Power Backup System
4.3.1 Location
The emergency power supply (such as generating sets)
should not be allowed to be installed above ground floor
or below the first basement level of the building. In
case of DG set located in basement, the ceiling of the
DG room shall be the ground floor slab. It is preferable
to install the standby generator in utility building. If
installed in the enclosed space, facilities for forced
ventilation shall be provided such that there is minimum
derating of the equipment. The generating set should
preferably be housed adjacent to MV switchgear in the
substation building to enable transfer of electrical load
efficiently and also to avoid transfer of vibration and
noise to the main building.
4.3.2 Room for Emergency Power Backup System
The capacity of standby generating set shall be sized
for emergency fire and life safty systems [see 4.2.1 (29)]
and other utilities as required and identified for
functional requirement of the building. Having chosen
the capacity and number of generating sets, required
space may be provided for their installation ( see Annex
D for general guidance). There shall be provision of
separate direct escape and entry from outside so that in
case of fire, electrical supplies can be disconnected to
1/ ZZ /V JA.
0.75 m
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:
7
1.0
TRANSFORMER
1.0
m m
TRANSFORMER WITH WALL ON TWO SIDES
TRANSFORMER WITH WALL ON THREE SIDES
X TO BE AS PER 4.2.1(17)
TRANSFORMER IN ENCLOSED ROOM MULTIPLE TRANSFORMERS IN A ROOM
1 A MINIMUM RECOMMNEDED SPACING BETWEEN THE TRANSFORMER PERIPHERY AND WALLS
Fig. 1 — ( Continued )
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
25
3000 Maxi
E
nr
\ CLEAR HEIGHT
1200 Min.
\ J
PANEL
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TRANSFORMER - 3
DRY TYPE
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FRONT
CAPACITOR
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PANEL -2
CAPACITOR
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PANEL -4
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PANEL -n
-LENGTH-
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X TO BE AS PER 4.2.1(17)
All dimensions in millimetres.
IB TYPICAL LAYOUT OF SUBSTATION WITH DRY TYPE EQUIPMENT IN A SINGLE ROOM
Fig. 1 Typical Layout of Substation Including Minimum Recommended Spacing of
Transformer Periphery from Walls
26
NATIONAL BUILDING CODE OF INDIA 2016
avoid additional losses which may be caused due to
electrical supply, present at the time of fire. The height
of diesel generating (DG) set rooms shall however be
not more than 3 000 mm above the DG set height, unless
required due to DG room ventilation requirements.
Adequate space shall be provided for storing of fuel.
Facilities including space at appropriate positions,
relative to the location of the installed equipment has
to be kept in the layout design for removal of equipment
or sub-assemblies for repair or maintenance. When it
is located at a place, other than the ground level with
direct equipment access, a hatch or ramp shall be
provided.
4.3.3 Installation and Other Requirements
Following installation and other requirements shall also
be complied with:
a) Day-oil tanks for the DG sets shall be in
compliance with The Petroleum Act, 1934.
b) The emergency installation shall comply with
the norms laid down by the Central Pollution
Control Board (CPCB) and shall also be in
compliance with The Petroleum Act, 1 934 and
guidelines of Oil Industry Safety Directorate
(OISD). Compartmentation for fire protection
with detection and first-aid protection
measures is essential.
NOTE — Different type of fire safety requirements
exists for the diesel engine and generator for the oil
storage area and for the switchgear (see also Part 4
‘Fire and Life Safety ‘of the Code).
c) Acoustic enclosure for DG sets/acoustic lining
of the DG room and ventilation system for DG
room shall be in line with the requirements of
CPCB. If DG set is located outdoors, it shall
be housed in acoustics enclosure as per the
requirements of CPCB norms. For acoustical
enclosures/treatment, reference shall also be
made to Part 8 ‘Building Services, Section 4
Acoustics, Sound Insulation and Noise
Control’ of the Code.
d) The generator house should have proper
ventilation for engine combustion
requirements and as well as for the body heat
removal apart from the heat removal from
radiator or cooling tower, fire fighting
equipment, etc. The other requirements given
in Part 4 ‘Fire and Life Safety’ of the Code
for room for emergency power backup system
including DG set room shall also be complied
with.
e) Other environmental requirements under the
provisions of Environment Protection Rules,
1986 and norms laid down by CPCB, as
amended from time-to-time shall be taken into
account particularly from the aspect of engine
emissions including the height of exhaust pipe
and permitted noise levels/controls.
4.4 Location of MV/LV Switch Room Other than in
Substation
In large installations other than where a substation is
provided, a separate switch room shall be provided;
this shall be located as close to the electrical load centre
as possible, on the ground floor or on the first basement
level of the building. Suitable cable trays shall be laid
with minimum number of bends from the points of entry
of the main supply cable to the position of the main
switchgear. The switch room shall also be placed in
such a position that riser shafts may readily be provided
therefrom to the upper floors of the building in one
straight vertical run. In larger buildings, more than one
riser shaft may be required and then horizontal trays
may also be required for running cables from the switch
room to the foot of each rising main. Such cable trays
shall either be reserved for specific voltage grades or
provided with a means of segregation for medium, low
and extra low voltage installations, such as call-bell
systems, telephone installations, fire detection and
alarm system, security systems, data cables and
announcement or public address system. Cables/wires
for emergency fire and life safety services and their
routing shall be in accordance with 4.2.1 (29) and Part
4 ‘Fire and Life Safety’ of the Code so that these
services are maintained even in the event of a fire.
4.5 Location and Requirements of Distribution
Panels
All distribution panels, switchgears shall be installed
in readily accessible position. The electrical control
gear distribution panels and other apparatus, which are
required on each floor may conveniently be mounted
adjacent to the rising mains, and adequate space
considering clearances required as per 5.3.6.8 shall be
provided at each floor for this purpose.
4.6 Substation Safety
The owner and the operator of any substation shall be
collectively and severally be responsible for any lapse
or neglect leading to an accident or an incidence of an
avoidable abnormality and shall take care of the
following safety requirements:
a) Enclose the substation or similar equipment
where necessary to prevent, so far as is
reasonably practicable, danger of electric
shock or unauthorized access;
b) Enclose any part of the substation which is
open to the air, with a fence (earthed efficiently
at both ends) or wall not less than 1 800 mm
(preferably not less than 2 400 mm) in height;
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
27
to prevent, so far as is reasonably practicable,
danger of electric shock or unauthorized
access;
c) Ensure that there are at all times displayed,
1) sufficient safety signs of such size and
placed in such positions as are necessary
to give due warning of such danger as is
reasonably foreseeable in the
circumstances;
2) a notice which is placed in a conspicuous
position and which gives the location or
identification of the substation, the name
of each generator or distributor who owns
or operates the substation equipment
making up the substation and the
telephone number where a suitably
qualified person appointed for this
purpose by the generator or distributor
will be in constant attendance; and
3) such other signs, which are of such size
and placed in such positions, as are
necessary to give due warning of danger
having regard to the siting of, the nature
of, and the measures taken to ensure the
physical security of, the substation
equipment;
d) Take all reasonable precautions to minimize
the risk of fire associated with the equipment;
and
e) Ensure that, in addition to provisions
mentioned in (c), name and emergency
telephone number of the authorized personnel
shall also be displayed at the substation and
instructions covering schematic diagram;
requirements of switchgear interlocking, if
any; and permission requirements, if any, for
load limitations on (incoming) feeders; be also
prominently displayed.
4.7 Overhead Lines, Wires and Cables
All erections/alterations having relation to overhead
lines, wires and cables shall comply with Central
Electricity Authority regulations and the following.
However, in case of any conflict, the regulations shall
prevail.
4.7.1 Height Requirement
4.7.1. 1 While overhead lines may not be relevant within
buildings, regulations related to overhead lines are of
concern from different angles as follows:
a) Overhead lines may be required in building
complexes, though use of underground cables
is the preferred alternative.
b) Overhead lines may be passing through the
site of a building. In such a case the safety
aspects are important for the construction
activity in the vicinity of the overhead line as
well as portions of low height buildings that
may have to be constructed below the
overhead lines. Overhead lines running
adjacent to buildings pose hazard from the
aspect of certain maintenance activity (such
as use of a ladder on external face of a
building) causing temporary compromise of
the minimum safety clearance.
4. 7. 1.2 If at any time subsequent to the erection of an
overhead line, whether covered with insulating material
or not, or underground cable, any person who proposes
to erect a new building or structure or to raise any road
level or to carry out any other type of work whether
permanent or temporary or to make in or upon any
building, or structure or road, any permanent or
temporary addition or alteration, in proximity to an
overhead line or underground cable, such person and
the contractor whom he employs to carry out the
erection, addition or alteration, shall give intimation in
writing of his intention to do so, to the supplier or owner
and to the Electrical Inspector and shall furnish
therewith a scale drawing showing the proposed
building, structure, road or any addition or alteration
and scaffolding thereof required during the
construction. In this connection. Regulation 63 of
Central Electricity Authority (Measures Relating to
Safety and Electricity Supply) Regulations, 2010, as
amended from time-to-time shall also be complied with
{see Annex B).
4.7.1.3 Any person responsible for erecting an overhead
line will keep informed the authority(s) responsible for
services in that area for telecommunication, gas
distribution, water and sewage network, roads so as to
have proper coordination to ensure safety. He shall also
publish the testing, energizing programme for the line
in the interest of safety.
4.7.1.4 For minimum distance (vertical and horizontal)
of electric lines/wires/cables from buildings, reference
may be made to Part 3 ‘Development Control Rules
and General Building Requirements’ of the Code. In
this connection, Regulations 58, 60, 61, and 65 of
Central Electricity Authority (Measures Relating to
Safety and Electricity Supply) Regulations, 2010, as
amended from time-to-time shall also be complied with
{see Annex B).
4. 7. 1.5 Regulation 64 of Central Electricity Authority
(Measures Relating to Safety and Electricity’ Supply)
Regulations, 2010, as amended from time-to-time,
which govern conditions related to the storage of
material including storage of construction material at
a construction site, or other materials in a building in
28
NATIONAL BUILDING CODE OF INDIA 2016
vicinity of overhead lines and underground cables, shall
also be complied with ( see Annex B).
4.7.2 Position, Insulation and Protection of Overhead
Lines
4.7.2. 1 Any part of an overhead line which is not
connected with earth and which is not ordinarily
accessible shall be supported on insulators or
surrounded by insulation. Any part of an overhead line
which is not connected with earth and which is
ordinarily accessible shall be,
a) made dead; or
b) so insulated that it is protected, so far it is
reasonably practicable, against mechanical
damage or interference; or
c) adequately protected to prevent danger.
4.7.2.2 Any person responsible for erecting a building
or structure which will cause any part of an overhead
line which is not connected with earth to become
ordinarily accessible shall give reasonable notice to the
licensee or distributor who owns or operates the
overhead line of his intention to erect that building or
structure.
The expression ‘ordinarily accessible’ means the
overhead line might be reachable by hand if any
scaffolding, ladder or other construction was erected
or placed on/in, against or near to a building or
structure.
4.7.2.3 Any bare conductor not connected with earth,
which is part of a low voltage overhead line, shall be
situated throughout its length directly above a bare
conductor which is connected with earth.
4.7.3 Precautions against Access and Warnings of
Dangers
4.7.3. 1 Every support carrying a high voltage overhead
line shall be fitted with anti-climbing devices to prevent
any unauthorized person from reaching a position at
which any such line will be a source of danger. In this
connection, Regulation 73(3) of Central Electricity
Authority (Measures Relating to Safety and Electricity
Supply) Regulations, 2010, as amended from time-to-
time shall also be complied with (see Annex B).
4. 7.3.2 Every support carrying a high voltage overhead
line, and every support carrying a low voltage overhead
line incorporating bare phase conductors, shall have
attached to it sufficient safety signs and placed in such
positions as are necessary to give due warning of such
danger as is reasonably foreseeable in the
circumstances.
4. 7.3.3 Poles supporting overhead lines near the road
junctions and turnings shall be protected by a masonry
or earth fill structure or metal barricade, to prevent a
vehicle from directly hitting the pole, so that the vehicle,
if out of control, is restrained from causing total damage
to the live conductor system, likely to lead to a
hazardous condition on the road or footpath or building.
4.7.4 Fitting of Insulators to Stay Wires
Every stay wire which forms part of, or is attached to,
any support carrying an overhead line incorporating
bare phase conductors (except where the support is a
lattice steel structure or other structure entirely of metal
and connected to earth) shall be fitted with an insulator,
no part of which shall be less than 3 m above ground or
above the normal height of any such line attached to
that support.
4.8 Maps of Underground Networks
4.8.1 Any person or organization or authority laying
cables shall contact the local authority in charge of that
area and find out the layout of,
a) water distribution pipe lines in the area;
b) sewage distribution network;
c) telecommunication network,
d) gas pipeline network; and
e) existing power cable network,
and plan the cable network in such a manner that the
system is compatible, safe and non-interfering either
during its installation or during its operation and
maintenance. Plan of the proposed cable installation
shall be brought to the notice of the other authorities
referred above.
4.8.2 Suitable cable markers and danger sign as will
be appropriate for the safety of the workmen of any of
the systems shall be installed along with the cable
installation. Cable route markers shall be provided at
every 20 m and also at turnings and/or crossings.
4.8.3 Notification of testing and energization of the
system shall also be suitably publicized for ensuring
safety.
4.8.4 Any person or organization or authority associated
with the operation and maintenance of services in a
complex is required to have a complete integrated
diagram or drawings of all services with particular
emphasis on the hidden pipes, cables, etc, duly kept
up-to-date by frequent interaction with all agencies
associated with the maintenance work.
Organization or agency responsible for laying cables
shall have and, so far it is reasonably practicable, keep
up-to-date, a map or series of maps indicating the
position and depth below surface level of all networks
or parts thereof which he owns or operates. Where
adequate mapping has not been done and the excavation
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
29
for cable laying reveals lines pertaining to any of the
other services, record of three dimensional location
should be marked and recorded. Even where mapping
exists, it may be examined if the records have become
obsolete due to change such as, in road level. Any map
prepared or kept shall be available for inspection by
any authority, such as municipality, water supply,
sewage, service providers, general public provided they
have a reasonable cause for requiring reference to any
part of the map.
4.8.5 Any agency working on any one or more service
(occupying the underground space for service pipes,
cables, etc) should keep the other agencies informed
of the work so that an inadvertent action will not cause
a disruption of service. Each agency should be
responsible for keeping the latest information with the
central authority of such records and should be
responsible to ensure that the modifications, if any are
duly updated and notified among the other agencies.
5 DISTRIBUTION OF SUPPLY AND CABLING
5.1 General
5.1.1 In the planning and design of an electrical wiring
installation, due consideration shall be made of all the
prevailing conditions. It is recommended that advice
of a competent electrical engineer be sought at the initial
stage itself with a view to providing an installation that
will prove adequate for its intended purpose, be reliable,
safe and efficient.
5.1.2 A certain redundancy in the electrical system is
necessary and has to be built in from the initial design
stage itself. The extent of redundancy will depend on
the type of load, its criticality, normal hours of use,
quality of power supply in that area, coordination with
the standby power supply, capacity to meet the starting
current requirements of large motors, etc.
5.1.3 In modem building technology, following high
demands are made of the power distribution system
and its individual components:
a) Long life and good service quality;
b) Safe protection in the event of fire;
c) Low fire load;
d) Flexibility in load location and connection, but
critical in design;
e) Low space requirement; and
f) Minimum effort involved in carrying out
retrofits.
5.1.4 The high load density in modem large buildings
and high rise buildings demands compact and safe
solution for the supply of power. The use of busbar
trunking system is ideal for such applications. Busbar
trunking can be installed in vertical risers shafts or
horizontally in passages for transmission and
distribution of power. They allow electrical installations
to be planned in a simple and neat manner. In the
building complexes, additional safety demands with
respect to fire barriers and fire load can also be met
with the use of busbar trunking. Busbar trunking system
also reduces the combustible material near the area with
high energy in comparison with other distribution
systems such as cables and makes the building safe from
the aspect of vulnerability to fire of electrical origin.
In addition, unlike cable systems the reliability of a
busbar trunking system is very high. These systems also
require very little periodic maintenance. Choice of
busbar trunking for distribution in buildings can be
made on the basis of,
a) reduced fire load (drastically reduced in
comparison to the cable system);
NOTE — Insulation materials of cables are required
to be fire resistant and an essential performance
requirement is that the insulation material may bum
or melt and flow when directly exposed to a
temperature (or fire) higher than what it is class
designated for, but should not continue to bum after
the flame or the source of heat or file is withdrawn.
Even if the above fire resistant property is exhibited
by the cable insulation, a large collection of cables
will make the cable insulation fail to exhibit this
retardant property. While specific guidelines for
limiting number of cable and bunching is not
available and in such cases the switch over to a bus
trunking system is the proper alternative.
b) reduced maintenance over its entire lifetime;
c) longer service lifetime in comparison with a
cable distribution; and
d) enhanced reliability due to rigid bolted joints
and terminations and extremely low possibility
of insulation failure.
5.2 System of Supply
5.2.1 All electrical apparatus shall be suitable for the
voltage and frequency of supply.
5.2.2 In case of connected load of 100 kVA and above,
the relative advantage of high voltage three-phase
supply should be considered. Though the use of high
voltage supply entails the provisions of space and the
capital cost of providing suitable transformer substation
at the consumer’s premises, the following advantages
are gained:
a) advantage in tariff;
b) more effective earth fault protection for heavy
current circuits;
c) elimination of interference with supplies to
other consumers permitting the use of large
size motors, welding plant, etc; and
d) better control of voltage regulation and more
constant supply voltage.
30
NATIONAL BUILDING CODE OF INDIA 2016
NOTE — Additional safety precautions required to be observed
in HV installations shall also be kept in view.
In many cases there may be no choice available to the
consumer, as most of the licensees have formulated their
policy of correlating the supply voltage with the
connected load or the contract demand. Generally the
supply is at 240 V single phase up to 5 kVA,
4 1 5/240 V 3-phase from 5 kVA to 1 00 kVA, 1 1 kV (or
22 kV) for loads up to 5 MVA and 33 kV or 66 kV for
consumers of connected load or contract demand more
than 5 MVA.
5.2.3 In very large industrial buildings where heavy
electric demands occur at scattered locations, the
economics of electrical distribution at high voltage from
the main substation to other subsidiary transformer
substations or to certain items of plant, such as large
motors and furnaces, should be considered. The relative
economy attainable by use of medium or high voltage
distribution and high voltage plant is a matter of expert
judgment and individual assessment in light of
experience by a professionally qualified electrical
engineer.
5.3 Substation Equipment and Accessories
Substations require an approval by the Electrical
Inspectorate. Such approval is mandatory before
energizing the substation. It is desirable to get the
approval for the general layout, schematic layout,
protection plan, etc, before the start of the work from
the Inspectorate. All substation equipment and
accessories and materials, etc, shall conform to relevant
Indian Standards, wherever they exist, otherwise the
consumer (or his consultant) shall specify the standards
to which the equipment to be supplied confirms and
that shall be approved by the authority. Manufacturers
of equipment have to furnish certificate of conformity
as well as type test certificates for record, in addition
to specified test certificates for acceptance tests and
installation related tests for earthing, earth continuity,
load tests and tests for performance of protective gear.
5.3.1 Supply Company’s High Voltage Meter Board
In case of single point high voltage metering, energy
meters shall be installed in building premise as
per 4.2.2. 1, at such a place which is readily accessible
to the owner/operator of the building and the Authority.
The supplier or owner of the installation shall provide
at the point of commencement of supply a suitable
isolating device fixed in a conspicuous position at not
more than 1 .7 m above the ground so as to completely
isolate the supply to the building in case of emergency.
In this connection, Central Electricity Authority
(Installation and Operation of Meters) Regulations,
2006, as amended from time-to-time shall be complied
with.
5.3.2 High Voltage Switchgear
5. 3. 2.1 The selection of the type of high voltage
switchgear for any installation inter alia depends upon
the following:
a) Voltage of the supply system;
b) Prospective short-circuit current at the point
of supply;
c) Size and layout of electrical installation;
d) Accommodation available; and
e) Nature of industry.
Making and breaking capacity of switchgear shall be
commensurate with short-circuit potentialities of the
supply system and the supply authority shall be
consulted on this subject. HV switchgear and
controlgear shall conform to the accepted standards
[8-2(14)] and other relevant Indian Standards.
5.3. 2. 2 Guidelines on various types of switchgear
equipment and their choice for a particular application
shall be in accordance with good practice [8-2(12)].
5.3.2 .3 In extensive installations of switchgear (having
more than four incoming supply cables or having more
than 12 circuit breakers), banks of switchgears shall be
segregated from each other in order to prevent spreading
of the risk of damage by fire or explosion arising from
switch failure. Where a busbar section switch is installed,
it shall also be segregated from adjoining banks in the
same way {see good practice [8-2(13)]}.
5.3.2.4 It should be possible to isolate any section from
the rest of the switchboards such that work might be
undertaken on this section without the necessity of
making the switchboard dead. Isolating switches used
for the interconnection of sections or for the purpose
of isolating circuit-breakers of other apparatus, shall
also be segregated within its compartment so that no
live part is accessible when work in a neighbouring
section is in progress.
5.3.2. 5 In the case of double or ring main supply,
switchgears with interlocking arrangement shall be
provided to prevent simultaneous switching of two
different supply sources. Electrical and/or mechanical
interlocks may preferably be provided.
5.3.3 HV Cables
5.3.3. 1 The sizing of the cable shall depend upon the
method of laying cable, current to be carried,
permissible maximum temperature it shall withstand,
voltage drop over the length of the cable, the
prospective short-circuit current to which the cable may
be subjected, the characteristics of the overload
protection gear installed, load cycle, thermal resistivity
of the soil and the operating voltage {see also good
practice [8-2(15)]}.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
31
5.3.3. 2 All HV cables shall be installed in accordance
with good practice [8-2(15)]. TheHV cables shall either
be laid on the cable rack/built-up concrete trenches/
tunnel/basement or directly buried in the ground
depending upon the specific requirement. When HV
cable is hanging/running below the basement ceiling
slab, the cable shall be laid in a fire rated enclosure/
cable tray. The advice of the cable manufacturer with
regard to installation, jointing and sealing should also
be followed.
5.3.4 High Voltage Bus Bar Trunking/Ducting
HV bus bar system is used for transporting power
between HV generators, transformers and the infeed
main switchgear of the main HV switchgear.
Generally three types of bus ducts, namely non-
segregated, segregated and isolated phase bus duct
are used. The non-segregated bus ducts consist of three
phase bus bars running in a common enclosure made
of steel or aluminium. The enclosure shall provide
safety for the operational personnel and shall reduce
chances of faults. HV interconnecting bus bar trunking
for a.c. voltage above 1 kV up to and including 36 kV
shall conform to accepted standard [8-2(16)]. The
enclosures shall be effectively grounded.
Segregated phase bus ducts are similar to non-
segregated phase ducts except that metal or isolation
barriers are provided between phase conductors to
reduce chances of phase to phase faults. However, it is
preferable to use metal barriers.
In the case of isolated bus ducts, each phase conductor
shall be housed in a separate non-magnetic enclosure.
The bus duct shall be made of sections which are
assembled together at site to make complete assembly.
The enclosure shall be of either round or square shape
and welded construction. The enclosures of all phases
in general should be supported on a common steel
structure.
Seismic supports shall be provided for busbar trunking
having continuous straight lengths of more than 24 m
at a single stretch.
The bus duct system shall be coordinated with
connecting switchgear so as to provide adequate
protection.
When busbar trunking is crossing different fire
compartments, they shall have fire barriers of same
rating as that of the compartment (see also Part 4 ‘Fire
and Life Safety’ of the Code).
5.3.5 Transformers
5.3.5. 1 General design objective while selecting the
transformer(s) for a substation should be to provide at
least two or more transformers, so that a certain amount
of redundancy is built in, even if a standby system is
provided. The total installed transformer capacity shall
be at least 15 to 20 percent higher than the anticipated
maximum demand. With growing emphasis on energy
conservation, the system design is made for both
extremes of loading. During the periods of lowest load
in the system, it would be desirable to operate only one
transformer and to subsequently switch on the
additional transformers as the load increases during the
day. Total transformer capacity is generally selected
on the basis of present load, possible future load,
operation and maintenance cost and other system
conditions. The selection of the maximum size
(capacity) of the transformer is guided by the short-
circuit making and breaking capacity of the switchgear
used in the medium voltage distribution system.
Maximum size limitation is important from the aspect
of feed to a downstream fault. The transformers shall
conform to accepted standards [8-2(17)] and other
relevant Indian Standards.
5. 3. 5. 2 For reasons of reliability and redundancy it is
normal practice to provide at least two transformers
for any important installation. Interlinking by tie lines
is an alternative to enhance reliability/redundancy in
areas where there are a number of substations in close
vicinity, such as a campus with three or four multi¬
storeyed blocks, each with a substation. Ring main type
of distribution is preferred for complexes having a
number of substations.
5.3.6 Medium or Low Voltage Switchgear and
Controlgear and their Assemblies
5.3.6. 1 The selection of the type of medium or low
voltage switchgear for any installation inter alia
depends upon the following:
a) Voltage of the distribution system;
b) Prospective circuit current at the point at
which the switchgear is proposed;
c) Prospective short-circuit current at which the
switchgear is proposed;
d) Accommodation available; and
e) Nature of industry.
The switchgear and controlgear and their assemblies
so selected shall comply with the relevant accepted
standards [8-2(18)], other relevant Indian Standards,
IEC 61439 (Part 1) : 2011 ‘Low-voltage switchgear and
controlgear assemblies — Part 1: General rules’ ( under
publication as adopted Indian Standard) and IEC 61439.
(Part 2): 20 1 1 ‘Low-voltage switchgear and controlgear
assemblies — Part 2: Power switchgear and controlgear
assemblies ( under publication as adopted Indian
Standard).
5.3. 6. 2 Switchgear (and its protective device) shall
32
NATIONAL BUILDING CODE OF INDIA 2016
have breaking capacity not less than the anticipated
fault level in the system at that point. System fault
level at a point in distribution systems is
predominantly dependent on the transformer size and
its reactance. Parallel operation of transformers
increases the fault level.
5.3. 6.3 Where two or more transformers are to be
installed in a substation to supply a medium voltage
distribution system, the distribution system shall be
divided into separate sections, each of which shall be
normally fed from one transformer only unless the
medium voltage switchgear has the requisite short-
circuit capacity. Provision may, however, be made to
interconnect separate sections, through a bus coupler
in the event of failure or disconnection of one
transformer. See 4.2 for details of location and
requirements of substation.
5.3. 6.4 Isolation and controlling circuit breaker shall
be interlocked so that the isolator cannot be operated
unless the corresponding breaker is in open condition.
The choice between alternative types of equipment
may be influenced by the following considerations:
a) In certain installations supplied with electric
power from remote transformer substations,
it may be necessary to protect main circuits
with circuit-breakers operated by earth fault,
in order to ensure effective earth fault
protection.
b) Where large electric motors, furnaces or
other heavy electrical equipment is installed,
the main circuits shall be protected from
short-circuits by switch disconnector fuse or
circuit breakers. For motor protection, the
combination of contactor overload device
and fuse or circuit breakers shall have total
coordination at least for motor ratings up to
10 kW, and for ratings above 10 kW, it shall
be Type 2 coordination in accordance with
relevant part of accepted standards [8-2(18)].
Wherever necessary, back up protection and
earth fault protection shall be provided to the
main circuit.
c) Where means of isolating main circuits is
separately required, switch disconnector fuse
or switch disconnector may form part of main
switchboards.
5.3. 6. 5 It shall be mandatory to provide power factor
improvement capacitor at the substation bus. Suitable
capacitor may be selected in consultation with the
capacitor as well as switchgear manufacture
depending upon the nature of electrical load
anticipated on the system. Necessary switchgear/
feeder circuit breaker shall be provided for controlling
of capacitor bank.
Power factor of individual motor may be improved
by connecting individual capacitor banks in parallel.
For higher range of motors, which are running
continuously without much variation in load,
individual power factor correction at load end is
advisable.
NOTE — Care should be taken in deciding the kVAr rating
of the capacitor in relation to the magnetizing kVA of the
motor. Over rating of the capacitor may cause injury to the
motor and capacitor bank. The motor still rotating after
disconnection from the supply, may act as generator by self¬
excitation and produce a voltage higher than supply voltage.
If the motor is again switched on before the speed has fallen
to about 80 percent of the normal running speed, the high
voltage will be superimposed on the supply circuits and will
damage both the motor and the capacitor.
As a general rule, the kVAr rating of the capacitor
should not exceed the no-load magnetizing kVA of
the motor.
Generally it will be necessary to provide an automatic
control for switching on the capacitors matching the
load power factor and the bus voltage. Such a scheme
will be necessary as capacitors permanently switched
in the circuit may cause over voltage at times of light
load. Capacitor panel shall be provided with adequate
ventilation facility.
5. 3. 6. 6 Harmonics on the supply systems are
becoming a greater problem due to the increasing use
of electronic equipment, computer, fluorescent lamps,
LEDs and CFLs (both types have control/driver
circuits operating in switch mode), mercury vapour
and sodium vapour lighting, TV, microwave ovens,
latest air conditioners, refrigerators, controlled
rectifier and inverters for variable speed drives, power
electronics and other non-linear loads. Harmonics may
lead to almost as much current in the neutral as in the
phases. This current is almost third, fifth, seventh and
ninth harmonic. In such cases, phase rectification
devices may be considered at the planning stage itself
for the limits of harmonic voltage distortion.
With the wide spread use of thyristor and rectifier
based loads, there is a necessity of providing a full
size neutral; but this requirement is generally limited
to the 3-phase 4-wire distribution generally in
the 415/240 V.
5.3.6. 7 MV/LV Bus bar chambers
Bus bar chambers, which feed two or more circuits,
shall be controlled by a main disconnector (TP&N)
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
33
or TPN MCB to enable them to be disconnected from
the supply.
5. 3. 6. 8 Sufficient clearances as below shall be
provided for isolating the switchboard to allow access
for servicing, testing and maintenance (see. Fig. 2):
a) A clear space of not less than 1 m in width
shall be provided in front of the switchboard.
NOTE — In case the board has a shutter in the
front for aesthetic reasons, provided the opening
of the shutter shall satisfy the requirement of
working/safety space of 1 m in front of the
switchgear.
b) If there are any attachments or bare
connections at the back of the switchboard,
the space, if any, behind the switchboard shall
be either less than 200 mm or more than
750 mm in width, measured from the farthest
protruding part of any attachment or
conductor.
c) If the space behind the switchboard exceeds
750 mm in width, there shall be a passageway
from either end of the switchboard, clear to
a height of 1.8 m.
d) If two switchboards are facing each other, a
minimum distance of 2.0 m shall be
maintained between them.
The connections between the switchgear mounting and
the outgoing cable up to the wall shall be enclosed in
a protection pipe.
There shall be a clear distance of not less than 250 mm
between the board and the insulation cover, the
distance being increased for larger boards in order
that on closing of the cover, the insulation of the cables
is not subjected to damage and no excessive twisting
or bending in any case. The cable alley in the metal
board should enable within prescribed limit twisting
or bending of cable such that insulation of the cables
is not subjected to damage.
In this connection, for installation of voltages
exceeding 250 V, Regulation 37 of Central Electricity
Authority (Measures Relating to Safety and Electricity
Supply) Regulations , 2010, as amended from time-
to-time shall also be complied with (see Annex B).
5.3. 6. 9 Sufficient additional space shall be allowed
in substations and switchrooms to allow operation and
maintenance. Sufficient additional space shall be
allowed for temporary location and installation of
standard servicing and testing equipment. Space
should also be provided to allow for anticipated future
extensions.
5.3.6.10 Panels in a room or cubicle or in an area
surrounded by wall/fence, access to which is
controlled by lock and key shall be accessible to
authorized persons only.
Such installations shall be efficiently protected by
fencing not less than 1 800 mm in height or other means
so as to prevent access to the electric supply lines and
apparatus therein by an undesignated person and the
/z jy ;; // zz A // // // //T7-77-
— x
1.0 m Min
fV/Z //
T
V w /V // /V 7/
ENTRY / EXIT
OF EQUIPMENT /PANEL
AND AUTHORIZED PERSON
2A ONE SWITCH BOARD/PANEL 2B TWO SWITCH BOARDS/PANELS FACING EACH OTHER
X = Less than 200 mm (if switchboard/panel is
not accessible from behind)
= More than 750 mm (if switchboard/panel is
accessible from behind)
NOTE — X to be measured from the fathest protruding part of any attachment or conductor.
Fig. 2 Clearances around Switchboards In Enclosed Room
34
NATIONAL BUILDING CODE OF INDIA 2016
fencing of such area shall be earthed efficiently.
Sufficient clearances as per 53.6.8 shall be provided
between the switchboard and the wall/fence.
5.3.6.11 Except main LV panel, it will be preferable to
locate the sub-panels/distribution boards/sub-meter
boards near the load centre. Further, it should be
ensured that these panels are easily approachable. The
panels should have clear access from common areas
excluding staircase.
Where the switchboard is erected in a room of a building
isolated from the source of supply or at a distance from
it, adequate means of control and isolation shall be
provided both near the boards and at the origin of
supply. Sufficient clearances as per 53.6.8 shall be
provided.
53.6.12 All switchboards shall be of metal clad totally
enclosed type or any insulated enclosed pattern.
5.3.7 Medium or Low Voltage Cables
53.7.1 The sizing of the cable shall depend upon the
current to be carried, method of laying cable,
permissible maximum temperature it shall withstand,
voltage drop over the length of the cable, the
prospective short-circuit current to which the cable may
be subjected, the characteristics of the overload
protection gear installed, load cycle, thermal resistivity
of the soil and the operating voltage {see also good
practice [8-2(11)]}.
It is desirable to use flame retardant cables and wires
in electrical distribution systems. Availability of flame
retardant low smoke and halogen cable may also be
noted and considered accordingly.
It is recommended to use four core cable in place of
three and half core to minimize heating of neutral core
due to harmonic content in the supply system and also
avoidance of overload failures. All cables shall be
installed in accordance with good practice [8-2(11)].
The advice of the cable manufacturer with regard to
installation, jointing and sealing should also be
followed.
In final circuits where cable size of 16 mm2 and below
are used, these shall be 4 core cables only to avoid the
possibility of neutral overload, (except for equipment
such as motors, heaters which offer balanced 3 phase
load and do not require a neutral connection. As a result
it is not desirable to use half-size neutral conductor as
possibility of neutral conductor overload due to
harmonics is likely. Larger feeders (size greater than
16 mm2) may revert to use 3 Vi core cables.
53.7.2 Colour identification of cores of non-fexible
cables {see also good practice [8-2(19)]}
The colour of cores of non-flexible cables shall be in
accordance with the following:
SI
Function
Colour Identification of Core of Rubber of
No.
PVC Insulated Non-flexible Cable, or of
Sleeve or Disc to be Applied to Conductor
or Cable Code
(1)
(2)
(3)
i) Protective or earthing
ii) Phase of a.c. single-phase circuit
iii) Neutral of a.c. single or three-phase circuit
iv) Phase R of 3-phase a.c. circuit
v) Phase Y of 3-phase a.c. circuit
vi) Phase B of 3 -phase a.c. circuit
vii) Positive of d.c. 2-wire circuit
viii) Negative of d.c. 2-wire circuit
ix) Outer (positive or negative) of d.c. 2-wire circuit
derived from 3 -wire system
x) Positive of 3-wire system (positive of 3-wire d.c.
circuit)
xi) Middle wire of 3-wire d.c. circuit
xii) Negative of 3-wire d.c. circuit
xiii) Functional earth-telecommunication
NOTES .
1 Bare conductors are also used for earthing and earth continuity conductors. But it is preferable to use insulated conductors with
green coloured insulation with yellow stripes.
2 As alternative to the use of red, yellow or blue colour may be used, if desired in large installations, up to the final distribution board.
3 For armoured PVC-insulated cables and paper-insulated cables, see relevant Indian Standard. _ _ _ _ _
Green and yellow {see Note 1)
Red [or yellow or blue (see Note 2)]
Black
Red
Yellow
Blue
Red
Black
Red
Red
Black
Blue
Cream
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
35
5.3.7.3 Colour, identification of cores of flexible cables
and flexible cords {see also good practice [8-2(19)]}
The colour of cores of flexible cables and flexible cords
shall be in accordance with the following:
SI
Number
Function of
Colour(s) of
No.
of
Core
Core
Cores
(1)
(2)
(3)
(4)
i)
1
Phase
Brown0
Neutral
(Light) Blue
Protective or
Green and
earthing
yellow
ii)
2
Phase
Brown
Neutral
(Light) Blue0
iii)
3
Phase
Brown
Neutral
(Light) Blue0
Protective or
Green and
earthing
yellow
iv)
4 or 5
Phase
Brown or
Neutral
black0
Protective or
(Light) Blue0
earthing
Green and
yellow
1 1 Certain alternatives are allowed in wiring regulations.
5.3.8 MV/LV Bus bar Trunking/Rising Mains
5.3.8.1 Where heavy loads and/or multiple distribution
feeders are required to be supplied, busbar/rising main
systems are preferred. The busbars are available for
continuous run from point to point or with tap offs at
standard intervals and have to be chosen as per specific
requirement. Seismic supports shall be provided for bus
trunking having continuous straight lengths of more than
24 m at a single stretch. There are following two types
of MV/LV bus duct systems for power distribution:
a) Conventional type; and
b) Compact and sandwich type.
5.3. 8.1.1 Conventional type bus duct
These are used for large power handling between
transformer and switchgear or between switchgear and
large power loads such as compressor drive motor, etc.
This type is generally used in plant rooms, riser shafts,
substations, etc. These are generally air insulated with
intermediate ceramic support insulators enclosed in a
metallic enclosure, which should be earthed. They have
the least amount of combustible material. However,
when these are crossing different fire compartments,
they shall have fire barriers of same rating as that of
the compartment {see also Part 4 ‘Fire and Life Safety’
of the Code).
Conventional type bus ducts with non-metallic
enclosures are also available. However, such bus ducts
shall be used only, if essential and with appropriate
additional care.
5.3. 8. 1.2 Compact type bus duct
Compact type bus ducts are used within areas of the
building which have space restrictions, etc, for aesthetic
and functional reasons. These are either air insulated
or sandwich type. They may be used in false ceiling
spaces or even in corridors and shafts for distribution
without any false ceiling as they provide an aesthetically
acceptable finish to merge with other building elements
such as beams, ducts or pipes in functional buildings.
The insulation material in such ducts are generally glass
fibre tape or epoxy encapsulation in combination with
ceramic supports/spacers. These bus ducts should be
duly enclosed by a metallic enclosure, which should
be earthed.
In case of compact air insulated type bus ducts crossing
different fire compartments, they shall have fire barriers
of same rating as that of the compartment {see also
Part 4 ‘Fire and Life Safety’ of the Code).
5.3.8.2 The bus duct system shall be coordinated with
connecting switchgear so as to provide adequate
protection.
5.3. 8.3 Seismic supports shall be provided for busbar
trunking having continuous straight lengths of more
than 24 m at a single stretch.
5.3. 8.4 Where the number of individual units/flats/
shops/offices on a floor in a building are more than 24,
multiple rising mains are recommended for power
distribution.
5.3.8.5 The low voltage bus bar trunking shall conform
to accepted standard [8-2(20)].
5.4 Reception and Distribution of Main Supply
5.4.1 Control at Point of Commencement of Supply
5.4. 1.1 The supplier shall provide a suitable metering
switchgear in each conductor of every service line other
than an earthed or earth neutral conductor or the earthed
conductor of a concentric cable within a consumer’s
premises, in an accessible position and such metering
switchgear shall be contained within adequately
enclosed fireproof receptacle. Where more than one
consumer is supplied through a common service line,
such consumer shall be provided with an independent
metering switchgear at the point of rigid junction to
the common service. Every electric supply line other
than the earthed or earthed neutral conductor of any
system or the earthed external conductor of a concentric
cable shall be protected by a suitable switchgear by its
36
NATIONAL BUILDING CODE OF INDIA 2016
owner. In this connection, Regulation 14 and 41 of
Central Electricity Authority' (Measures Relating to
Safety and Electricity Supply) Regulations , 2010, as
amended from time-to-time shall also be complied with
( see Annex B).
In case of high rise buildings, the supplier or owner of
the installation shall provide at the point of
commencement of supply a suitable isolating device
with cut-out or breaker to operate on all phases except
neutral in the 3-phase, 4-wire circuit and fixed in a
conspicuous position at not more than 1 .7 m above the
ground so as to completely isolate the supply to the
building in case of emergency. In this connection,
Regulation 36 of Central Electricity Authority
(Measures Relating to Safety and Electricity > Supply)
Regulations , 2010, as amended from time-to-time shall
also be complied with (see Annex B).
The supplier shall provide and maintain on the
consumer’s premises for the consumer’s use, a suitable
earthed terminal in an accessible position at or near
the point of commencement of supply. In this
connection, Regulation 16 of Central Electricity
Authority (Measures Relating to Safety and Electricity
Supply) Regulations, 2010, as amended from time-to-
time shall also be complied with (see Annex B).
No cut-out, link or switch other than a linked switch
arranged to operate simultaneously on the earthed or
earthed neutral conductor and live conductor shall be
inserted or remain inserted in any earthed or earthed
neutral conductor of a two wire-system or in any earthed
or earthed neutral conductor of a multi-wire system or
in any conductor connected thereto. This requirement
shall however not apply in case of,
a) a link for testing purposes, or
b) a switch for use in controlling a generator or
transformer.
In this connection, Regulation 15 (ii) of Central
Electricity Authority (Measures Relating to Safety and
Electricity Supply) Regulations, 2010, as amended from
time-to-time shall also be complied with (see Annex B).
The neutral shall also be distinctly marked.
5.4. 1.2 The main switch shall be easily accessible and
situated as near as practicable to the termination of
service line.
5. 4. 1.3 Where the conductors include an earthed
conductor of a two-wire system or an earthed neutral
conductor of a multi-wire system or a conductor which
is to be connected thereto, an indication of a permanent
nature shall be provided for identification in accordance
with Regulation 15 (i) of Central Electricity Authority’
(Measures Relating to Safety and Electricity- > Supply)
Regulations, 2010, as amended from time-to-time (see
Annex B).
5.4. 1.4 Energy > meters
5. 4. 1.4.1 Energy meters conforming to accepted
standards [8-2(21 )] and other relevant Indian Standards
shall be installed in all buildings at such a place which
is readily accessible to the owner/operator/occupant of
the building and the Authority. Meters should not be
located at an elevated area or a depressed area that does
not have access by means of a stairway of normal rise.
The height of meter display shall be between 750 mm
and 1 800 mm. In case the meter is provided with a
secondary display unit, this requirement applies to the
secondary display unit only. A minimum clearance of
50 mm should be maintained around the meter itself
for better inspection. This includes the space between
two meters, or between meter and the mounting box,
or between two mounting boxes as the case may be.
The energy meters should either be provided with a
protecting covering, enclosing it completely except the
glass window through which the readings are noted or
should be mounted inside a completely enclosed panel
provided with hinged arrangement for locking.
Additionally, for outdoor installations, the meters and
associated accessories shall be protected by appropriate
enclosure of level of protection IP 55 and ensuring
compliance with above conditions. The enclosure
should preferably be light coloured.
In large multi-storeyed buildings, installation of a large
number of energy meters at the ground floor (or first
basement) switch-room for the convenience of the
meter-reader poses high fire hazard. More than 24
energy meters on one switchboard is undesirable. In
such cases, where number of energy meters to be
installed for feeding exceeds 24, energy meters shall
be installed at each floor and therefore, the rising main
(bus trunking) with tapping point at individual floor
shall be provided for meters.
The energy meters shall be protected by suitable circuit
breaker. The provisions of 5.3. 6. 8 shall apply in case
of energy meters installed in boards.
5.4. 1.4.2 Main sources of energy, as given below shall
be metered, as required at entry into the premise/control
panel:
1) Utility grid points (high voltage/medium
voltage/low voltage),
2) Captive generator sets, and
3) On-site renewable energy system (if installed/
operational).
5. 4. 1.4. 3 Testing, evaluation, installation and
maintenance of energy meters shall be in accordance
with the good practice [8-2(22)].
5.4. 1.4.4 Centralized metering system
Smart metering and energy monitoring in a centralized
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
37
metering system are used to monitor, measure, and
control the demand of electrical loads in a building. These
systems are designed specifically for the control and
monitoring of those facilities in a building which have
significant electrical consumption, such as heating,
ventilation, air conditioning, lifts, pumps, and lighting
installations at multiple locations in a campus. The scope
may span from a single building to a group of buildings,
such as residential apartments under common ownership,
large multi-storeyed buildings, malls, university
campuses, office buildings, retail store networks,
factories, or any building with multi-tenanted occupancy.
These systems provide metering, submetering and
monitoring functions to allow facility and building
managers to gather data and insight that allow them to
make more informed decisions about demand
management and demand control across their sites.
For such buildings with centralized metering, several
main meters and sub-meters with following
requirements should be provided:
a) Main meters should be digital energy meters
with high accuracy, high sampling rates and
power quality parameters, that is, harmonics,
etc, for meters installed at incomer level.
b) Separate sub-meters should be provided for
all energy end uses and functional areas that
individually account for reasonable energy
consumption in the building. These may
include, but are not limited to, sub-meters for
HVAC system; common area lighting, raw
power, UPS, other common utility; lifts and
escalators, pumps, external and internal
lighting, individual units/flats/shops/ offices;
etc.
c) The sub-meters should be able to
communicate data for monitoring. At a
minimum, the sub-metering infrastructure
should facilitate the aggregation of total
energy use.
d) Adequate smart metering and energy
monitoring infrastructure should be installed
in order to help monitor operational energy
use and costs and to enable continuous energy
performance improvement.
Smart metering and energy monitoring system that can
display the following parameters should be installed
with two-way communicable smart meters:
1 ) Hourly energy demand and use;
2) Energy breakdown and mix and energv
consumption patterns;
3) Power quality analysis;
4) Energy consumption by process, department,
building, floor, etc;
5) Comparison of actual energy use with targets
or historical trends and benchmark energy key
performance indicators; and
6) Reporting on energy efficiency achieved.
These systems should also have the ability to utilize
near-real-time or time-of-use pricing through
integration of smart meters with the monitoring and
control system. The system should be capable of
supporting predictive demand for better demand
management and proactive demand control.
5.4.1.4.5 The Central Electricity Authority (Installation
and Operation of Meters) Regulations 2006, as
amended from time-to-time shall also be complied with.
5.4.2 Main Switches and Switchboard
5.4.2. 1 All main switches shall be either of metal-clad
enclosed pattern or of any insulated enclosed pattern
which shall be fixed at close proximity to the point of
entry of supply. Every switch shall have suitable ingress
protection level rating (IP), so that its operation is
satisfactory and safe in the environment of the
installation.
NOTE — Woodwork shall not be used for the construction or
mounting of switches and switch boards installed in a building.
5.4.2.2 Location
The main switchboard shall comply with the following
requirements relating to its location:
a) The location of the main board should be such
that it is easily accessible to firemen and other
personnel to quickly disconnect the supply in
case of emergencies. If the room is locked for
security reasons, means of emergency access,
by schemes such as break glass cupboard,
shall be incorporated.
b) Main switch board shall be installed in rooms
or fire safe cupboards so as to safeguard
against operation by unauthorized personnel.
Otherwise the main switch board shall have
lock and key facility for small installations in
residences or other occupancies having
sanctioned loads less than 5 kW.
c) Switchboards shall be placed only in dry
situations and in ventilated rooms and they
shall not be placed in the vicinity of storage
batteries or exposed to chemical fumes.
d) In damp situation or where inflammable or
explosive dust, gas or vapour is likely to be
present, the switchboard shall be totally
enclosed and shall have adequate degree of
ingress protection (IP). In some cases
flameproof enclosure may be necessitated by
particular circumstances [see 8-2(23)].
38
NATIONAL BUILDING CODE OF INDIA 2016
e) Switchboards shall not be erected above gas
stoves or sinks, or within 2.5 m of any washing
unit in the washing rooms or laundries, or in
bathrooms, lavatories or toilets, or kitchens.
f) In case of switchboards unavoidably fixed in
places likely to be located outdoors, exposed
to weather, to drip, or to abnormal moist
temperature, the outer casing shall be
weatherproof and shall be provided with
glands or bushings or adopted to receive
screwed conduit, according to the manner in
which the cables are run. The casing as well
as cable entries shall have suitable IP ratings
according to the installation.
g) Adequate illumination shall be provided for
all working spaces around the switchboards.
h) Easy access to the enclosure around
switchgear is essential to enable easy and safe
operation and maintenance. The provisions as
given in 5.3. 6.8 including requirements for
sufficient clearances shall be complied with.
5.4.2.3 Metal-clad switchgear shall be mounted on any
of the following types of boards:
a) Hinged-type metal boards — These shall
consist of a box made of sheet metal not less
than 2 mm thick and shall be provided with a
hinged cover to enable the board to swing
open for examination of the wiring at the back.
The board shall be securely fixed to the wall
by means of proper nuts and bolts designed
to take weight of the switch board and shall
be provided with a locking arrangement and
an earthing and neutral stud or bus. All wires
passing through the metal board shall be
protected by cable termination glands at the
entry hole. The earth stud should
commensurate with the size of earth lead /
leads. Alternatively, metal boards may be
made of suitable size iron angle section of
minimum size 35 mm x 35 mm x 6 mm or
iron channel section of minimum size 35 mm
x 25 mm x 6 mm frame work suitably mounted
on front with a 3 mm thick mild steel plate
and on back with 1.5 mm thick mild steel
sheet. No apparatus shall project beyond any
edge of panel. No fuse body shall be mounted
within 25 mm of any edge of the panel.
NOTE — Such type of boards are particularly
suitable for small switchboard for mounting metal-
clad switchgear connected to supply at low voltages.
b) Fixed-type metal boards — These shall
consist of an angle or channel iron frame fixed
on the wall or on floor and supported on the
wall at the top, if necessary.
NOTE — Such type of boards are suitable for both
small and large switchboards. They are particularly
suitable for large switchboards for mounting number
of switchgears or high capacity metal-clad
switchgear or both in an arrangement which do not
require rear access.
c) Protected-type switchboard — A protected
switchboard is one where all of the switchgear
and conductors are protected by metal or
halogen free plastic enclosures. They may
consist of a metal/plastic cubicle panel, or an
iron frame upon which metal-clad switchgears
are mounted. They usually consist of a main
switch, bus bars and circuit breakers or fuses
controlling outgoing circuits.
d) Outdoor-type switchboard — An outdoor-type
switchboard is one which is totally enclosed
and UV ray protected and having high ingress
protection against dust and moisture and
vermin-proof and high impact resistance
(IP 55 or higher and IK 10). Such
switchboards are of cubicle type and also
provide high impact resistance. Cubicle type
boards shall be with hinged doors interlocked
with switch-operating mechanisms. The doors
of these switchboards shall have facility to
ensure that it is always in closed conditions.
All such switches shall bear labels indicating
their functions.
NOTE — Such switchboards shall be located away
from areas likely to be crowded by the public.
Open type switchboards wherever existing in old
buildings shall be phased out and replaced with
protected-type switchboards with suitable circuit
breakers.
5.4. 2. 4 Recessing of boards
Where so specified, the switchboards shall be recessed
in the wall. Ample room shall be provided at the back
for connection and at the front between the switchgear
mountings (see 5.3. 6. 8).
5.4. 2.5 Marking of apparatus {see also good practices
[8-2(24)]}
Where a board is connected to voltage higher than
250 V, all the apparatus mounted on it shall be marked
with the following colours to indicate the different poles
or phases to which the apparatus or its different
terminals may have been connected:
a) Alternating current (three-phase) system:
Phase 1 - red, Phase 2 - yellow and Phase 3 -
blue; and 1 Neutral - black
b) Direct current (three-wire system ):
2 outer wire, Positive - red and Negative -
blue; and 1 Mid wire (Neutral) - black
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
39
Where four-wire three-phase wiring is done, the neutral
shall be in one colour and the other three phase conductors
in another colour (preferably brown) or shall be suitably
tagged or sleeved to ensure fool proof identification.
NOTE — Generally brown colour identification is adopted for
the phase conductors and black for neutral with additional tags
or sleeves or coloured tapes at terminations.
Earth continuity conductor shall be marked with green
colour or green with yellow line.
Where a board has more than one switchgear, each such
switchgear shall be marked to indicate the section of
the installation it controls. The main switchgear shall
be marked as such. Where there is more than one main
switchboard in the building, each such switchboard
shall be marked to indicate the section of the installation
and/or building it controls.
All markings shall be clear and permanent.
5.4.2.6 Drawings
Before proceeding with the actual construction, a proper
drawing showing the detailed dimensions and design
including the disposition of the mountings of the boards,
which shall be symmetrically and neatly arranged for
arriving at the overall dimensions, shall be prepared
along the building drawing. Such drawings will show
the mandatory clearance spaces if any, and clear height
below the soffit of the beam required to satisfy
regulations and safety considerations, so that other
designers or installers do not get into such areas or
spaces for their equipment.
5.4.3 Distribution Boards
A distribution board comprises one or more protective
devices against over current and ensuring the
distribution of electrical energy to the circuits.
Distribution board shall provide plenty of wiring space,
to allow working as well as to allow keeping the extra
length of connecting cables, likely to be required for
maintenance.
5.4.3. 1 Main distribution board shall be provided with
a circuit breaker on each pole of each circuit, or a switch
with a fuse on the phase or live conductor and a link on
the neutral or earthed conductor of each circuit. The
switches shall always be linked.
All incomers should be provided with surge protection
devices depending upon the current carrying capacity
and fault level (see 11). Surge protecting devices should
be provided with backup circuit breaker/fuses,
wherever required.
5.4.4 Branch Distribution Boards
5.4.4. 1 Branch MCB distribution boards shall be
provided, along with earth leakage protective device
(RCCB/RCD) in the incoming, with a fuse or a
miniature circuit breaker or both of adequate rating
setting chosen on the live conductor of each sub-circuit
and the earthed neutral conductor shall be connected
to a common link and be capable of being disconnected
individually for testing purposes. At least one spare
circuit of the same capacity shall be provided on each
branch distribution board. Further, the individual
branching circuits (outgoing) shall be protected against
over-current with miniature circuit breaker of adequate
rating. In residential/industrial lighting installations, the
various circuits shall be separated and each circuit shall
be individually protected so that in the event of fault,
only the particular circuit gets disconnected. In order
to provide protection against electric shock due to
leakage current for human being, a 30 mA RCCB/ RCD
shall be installed at distribution board incomer of
buildings, such as residential, schools and hospitals.
For all other buildings, a 100 mA RCCB/RCD will
suffice for prou against leakage current.
In case of phase segregated distribution boards, earth
leakage protective device shall be provided in the sub¬
incomer to provide phase wise earth fault protection.
The provision of sub-incomer in distribution board shall
be as per consumer requirement.
5. 4. 4. 2 Common circuit shall be provided for
installations at higher level (those in the ceiling and at
higher levels, above 1 m, on the walls) and for
installations at lower level but with separate switch
control (sockets for portable or stationery plug in
equipment). For devices consuming high power and
which are to be supplied through supply cord and plug,
separate wiring shall be done. For plug-in equipment
provisions shall be made for providing RCCB/RCD
protection in the distribution board.
5.4.4.3 It is preferable to have additional circuit for
kitchen and bathrooms. Such sub-circuit shall not have
more than a total of ten points of light, fans and 6 A
socket outlets. The load of such circuit shall be
restricted to 800 W and the wiring with 1 .5 mm2 copper
conductor cable is recommended. If a dedicated circuit
is planned for light fixtures, the load of such circuit
shall be restricted to 400 W and the wiring with 1 .5 mm2
copper conductor cable is recommended. If a dedicated
circuit is planned for 6A sockets the load of Such a
circuit shall be restricted to 800 W or a maximum of
8 numbers, whichever is lesser, controlling MCB should
be sized accordingly. The wiring shall be with 1 .5 mm2
copper conductor cable. If a separate fan circuit is
provided, the number of fans in the circuit shall not
exceed ten. Power sub-circuit shall be designed
according to the load but in no case shall there be more
than two 1 6 A outlets on each sub-circuit which can be
wired with 4 mnr for miscellaneous socket loads and
shall be with 4 mm2 copper conductor cable for
equipment consuming more than 1 kW. Power sockets
40
NATIONAL BUILDING CODE OF INDIA 2016
complying with the accepted standards [8-2(25)] with
current rated according to their starting load, wiring,
MCB, etc, shall be designed for special equipment
space heaters, air conditioners, heat pumps, VRF, etc.
For feeding final single phase domestic type of loads
or general office loads it is advisable to introduce
additional cables if required to allow lowering of short
circuit rating of the switchgear required at user end.
Use of hand held equipment fed through flexible cords
is safe.
5.4. 4.4 The circuits for lighting of common area shall
be separate. For large halls 3-wire control with
individual control and master control installed near the
entrance shall be provided for effective conservation
of energy. Occupancy sensors, movement sensors, lux
level sensors, etc, may also be considered as switching
options for lights, fans, TV, etc, for different closed
spaces (see also Part 11 ‘Approach to Sustainability’
of the Code).
5. 4. 4. 5 Where daylight is abundantly available,
particularly in large halls, lighting in the area near the
windows likely to receive daylight shall have separate
controls for lights, so that they can be switched off/
automatically reduce intensity selectively when daylight
is adequate, while keeping the lights in the areas remote
from the windows on (see also Part 1 1 ‘Approach to
Sustainability’ of the Code).
5.4.4. 6 Circuits for socket outlets may be kept separate
from circuits feeding fans and lights. Normally, fans
and lights may be wired on a common circuit. In large
spaces, circuits for fans and lights may also be
segregated. Lights may have group control in large halls
and industrial areas. While providing group control,
consideration may be givesyAmhenatureof use of the
area lit by a group. Consideni^tThas^^e given for
the daylight utilization, while groupn?^, so that a group
feeding areas near windows receiving daylight can be
selectively switched off during daylight period.
5.4.4.7 The load on any low voltage sub-circuit shall
not exceed 3 000 W. In case of a new installation, all
circuits and sub-circuits shall be designed with an initial
bad of about 2 500 W, so as to allow a provision of
Wit percent increase in load due to any future
modification. Power sub-circuits shall be designed
according to the load, where the circuit is meant for a
a specific equipment. Good practice is to limit a circuit
%o a maximum of three sockets, where it is expected
that there will be diversity due to use of very few sockets
in large spaces (example sockets for use of vacuum
cleaner). General practice is to limit it to two sockets
in a circuit, in both residential and non-residential
buildings and to provide a single socket on a circuit
for a known heavy load appliance such as air
conditioner, cooking range, etc.
5. 4.4. 8 In wiring installations at special places like
construction sites, stadia, shipyards, open yards in
industrial plants, etc, where a large number of high
wattage lamps may be required, there shall be no
restriction of load on any circuit but conductors used
in such circuits shall be of adequate size for the load
and proper circuit protection shall be provided. The
distribution boards (DBs) used in these areas shall be
of UV resistant, double insulated type with IP 66. or
higher degree of protection. Power tools and other
temporary equipment connected to these DBs shall be
sufficiently protected against electrical faults. Insulated
IP 66 sockets complying with the accepted standards
[8-2(25)] used in these DBs shall have interlocking
facility in addition to protection to ensure safe plugging
and unplugging of these equipment.
5.4.5 Location of Distribution Boards
a) The distribution boards shall be located as
near as possible to the centre of the load they
are intended to control.
b) These shall be fixed on suitable stanchion or
wall and shall be accessible for replacement/
reset of protective devices, and shall not be
more than 1.8 m from floor level.
c) These shall be of either metal-clad type, or
polycarbonate enclosure of minimum IP 42.
But, if exposed to weather or damp situations,
these shall be of the weatherproof type
conforming to IP 55 and, if installed where
exposed to explosive dust, vapour or gas, these
shall be of flameproof type in accordance with
accepted standards [8-2(26)]. In corrosive
atmospheres, these shall be treated with anti¬
corrosive preservative or covered with suitable
plastic compound.
d) Where two and/or more distribution boards
feeding low voltage circuits are fed from a
supply of medium voltage, the metal case shall
be marked ‘Danger 415 Volts’ and identified
with proper phase marking and danger marks.
e) Each shall be provided with a circuit list giving
diagram of each circuit which it controls and
the current rating of the circuit and size of fuse
element.
f) In wiring branch distribution board, total load
of consuming devices shall be divided as far
as possible evenly between the number of
ways in the board leaving spare circuits for
future extension.
g) Distribution board shall not be located at
structural expansion joints of the building.
h) Distribution board/other electrical outlets shall
have a minimum calculated separation
distance from lightning protection down-
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
41
conductors to avoid flash over in case of
lightning.
j) Walls with flushed distribution boards shall
have adequate support behind and surrounding
so that there is no physical weight on the
distribution board of the civil structure around.
Electrical switch sockets, etc, shall also be
avoided to be mounted behind the distribution
board to avoid touching the board from
behind.
5.4.6 Protection of Circuits
a) Appropriate protection shall be provided at
switchboards, distribution boards and at all
levels of panels for all circuits and sub-circuits
against short circuit, over-current and other
parameters as required. The protective device
shall be capable of interrupting maximum
prospective short circuit current that may
occur, without danger. The ratings and settings
of fuses and the protective devices shall be
coordinated so as to afford selectivity in
operation and in accordance with accepted
standards [8-2(27)].
b) Where circuit-breakers are used for protection
of a main circuit and of the sub-circuits
derived therefrom, discrimination in operation
may be achieved by adjusting the protective
devices of the sub-main circuit-breakers to
operate at lower current settings and shorter
time-lag than the main circuit-breaker.
c) Where HRC type fuses are used for back-up
protection of circuit- breakers, or where HRC
fuses are used for protection of main circuits,
and circuit-breakers for the protection of sub¬
circuits derived there from, in the event of
short-circuits protection exceeding the short-
circuits protection exceeding the short-circuits
capacity of the circuit-breakers, the HRC fuses
shall operate earlier than the circuit-breakers;
but for smaller overloads within the short-
circuit capacity of the circuit-breakers, the
circuit-breakers shall operate earlier than the
HRC fuse blows.
d) If rewireable type fuses are used to protect
sub-circuits derived from a main circuit
protected by HRC type fuses, the main circuit
fuse shall normally blow in the event of a
short-circuit or earth fault occurring on sub¬
circuit, although discrimination may be
achieved in respect of overload currents. The
use of rewireable fuses is restricted to the
circuits with short-circuit level of 4 kA; for
higher level either cartridge or HRC fuses
shall be used. However, use of rewireable fuse
is not desirable, even for lower fault level
areas. MCB’s provide a better and dependable
protection, as their current setting is not
temperable.
e) A fuse carrier shall not be fitted with a fuse
element larger than that for which the carrier
is designed.
f) The current rating of a fuse or circuit breaker
shall not exceed the current rating of the
smallest cable in the circuit protected by the
fuse.
g) Every fuse shall have its own case or cover
for the protection of the circuit and an indelible
indication of its appropriate current rating in
an adjacent conspicuous position.
h) All distribution board or panel incomer may
be protected by a surge protection device, if
found necessary (see 11). Separate HRC fuse/
CB with proper enclosure may be required in
series with the surge protection device with
main incomer. Back-up fuse/CB shall be of
the capacity not lower than that recommended
by the SPD manufacturer. Short circuit
withstand capability of the SPDs should be
coordinated with the HRC fuse/CB and SPD
should be selected to be matching the fault
power expected/calculated at that point.
5.4.7 Cascading, Discrimination and Limitation
Cascading and discrimination in switchgear
downstream and upstream shall be designed and
maintained such that the continuity of power in case of
any abnormal conditions such as overload, short circuit
and earth faults, etc is maintained and only faulty circuit
is isolated and power is made available to other loads.
Cascading technique allows the designer to select
circuit breakers of lower breaking capacities. Utilizing
the current limiting effect of the incoming breaker,
outgoing breaker can sustain the higher faults than its
capacity and even maintain the discrimination.
5.5 Protection Class of Equipment and Accessories
The class of ingress protection (IP) and protection
against mechanical impact (IK) {see also good practice
[8-2(6)] and IEC 62262:2002 ‘Degrees of protection
provided by enclosures for electrical equipment against
external mechanical impacts (IK code)’} shall be
specitic depending on the requirement at the place of
installation.
5.6 Voltage and Frequency of Supply
It should be ensured that all equipment connected to
the system including any appliances to be used on it
are suitable for the voltage and frequency of supply of
the system. The nominal values of low and medium
voltage systems in India are 240 V and 415 V a.c.,
respectively, and the frequency is 50 Hz.
42
NATIONAL BUILDING CODE OF INDIA 2016
NOTE — The design of the wiring system and the sizes of the
cables should be decided taking into account following factors:
a) Voltage drop — This should be kept below
6 percent to ensure proper functioning of all
electrical appliances and equipment including
motors;
b) Thermal limit based current carrying capacity
of the cable with appropriate derating factors
applicable to the installation conditions;
c) Capacity to withstand the let through fault
current based on the fault level and the
controlling switchgear disconnection
characteristics.
5.7 Rating of Cables and Equipment
5.7.1 The current-carrying capacity of different types
of cables shall be chosen in accordance with good
practice [8-2(28].
5.7.2 The current ratings of switches for domestic and
similar purposes are 6 A, 16 A, 20 A and 25 A.
5.7.3 The current ratings of isolators and normal duty
switches and composite units of switches and fuses shall
be selected from one of the following values:
16, 25, 32, 63, 100, 160, 200, 320, 400, 500, 630,
800, 1 000 and 1 250 A.
5.7.4 The ratings of rewireable and HRC fuses shall be
in accordance with good practice [8-2(29)].
5.7.5 The current ratings of miniature circuit-breakers
shall be chosen from the values given below:
6, 10, 16,20,25,32,40,50, 63,80, 100 and 125 A.
5.7.6 The current ratings of moulded case circuit
breakers shall be chosen from the values given below:
100, 125, 160,200,250,315,400, 630,800, 1 000,
1 250 and 1 600A.
5.7.7 The current ratings of air circuit-breakers shall
be chosen from the values given below:
630, 800, 1 000, 1 250, 1 600, 2 000, 2 500, 3 200,
4 000A and 6 300 A.
5.7.8 The current ratings of the distribution fuse board
shall be selected from one of the following values:
6, 16, 25,32, 63 and 100 A.
5.8 Installation Circuits
5.8.1 The nominal cross-sectional area of copper phase
conductors in a.c. circuits and of live conductors in
d.c. circuits shall be not less than the values specified
below:
SI
No.
(1)
Type of Circuit
(2)
Minimum
Copper Wire
Size
(3)
Number of Circuits
(4)
i)
Lighting
1.5 mm2
2 or more
ii)
Socket-outlets, 6 A
2.5 mm2
Any number
Areas such as kitchens and laundries 3 x double
socket-outlets per circuit. Other areas up to 12
double socket-outlets
hi)
Signaling and control circuits
0.5 mm2
(see Note 1)
1
iv)
Socket-outlets, 1 6 A
2.5 mm2
v)
Water heater < 3 kW
2.5 mm2
1
vi)
Heaters or electric equipment
more than or equal to 3 kW
4.0 mm2
1
vii)
Free standing electric range
Separate oven and/or cook top
4.0 mm2
1
viii)
Air conditioner > 1.5 t
4.0 mnr
1
ix)
Permanently connected
appliances including
dishwashers, heaters, etc
2.5 mm2
1 above 10 A. Up to 10 A can be wired as part
of a socket-outlet circuit
x)
Appliance rated >3 kW<6 kW
6.0 mm2
—
XI)
Submains to garage or out¬
building
2.5 mm2
1 for each
xii)
Mains cable
It should be based on demand load/peaking
loads and future loading.
NOTE _ In multi -core flexible cables containing 7 or more cores and in signalling control circuits intended for electronic equipment
a minimum nominal cross -sectional area of 0. 1 mm 2 is permitted.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
43
5.8.2 Aluminum conductor cables in sizes less than
16 mm2 cause termination problems leading to heating
at the terminals and enhance the possibility of a fire. For
conductor sizes less than or equal to 1 6 mm2, only copper
conductor cables should be used.
5.8.3 Switch or isolator controlling a water heater or
geyser should not be located within 1 m from the
location of a shower or bath tub, to avoid a person in
wet condition reaching the switch or isolator. It is
preferable to provide the control switch outside the bath
room near the entrance and provide an indication at
the water heater. A socket or a connector block with
suitable protection against water spray should be
provided to connect the water heater. The above
considerations apply to switches for outdoor lights and
other appliances, with the objective of avoidance of
operation of a switch when a person is wet.
5.8.4 Sockets in kitchen, bathroom, toilet, garage, etc,
should not be provided within a height of 1 m from the
ground level. Similar care has to be taken for installations
involving fountains, swimming pools, etc. Light fittings
in such areas should be fed at low voltage, preferably
through an isolating transformer with a proper earth
leakage protection. Where possibility of a person in
contact with a wet surface has to operate or touch an
electrical switch or an appliance the circuit should be
protected by a 100/30 mA RCCB/RCD, as applicable.
5.8.5 Selecting and Installing Cables
5.8.5. 1 Cable insulation types
For the purpose of this Code, cables above 1 mm2 shall
have stranded conductors. All cables when installed, shall
be adequately protected against mechanical damage. This
can be carried out by either having additional protection,
such as being enclosed in PVC conduit or metal pipes,
or placing the cables in a suitable location that requires
no additional protection. The cables for wiring circuits
in electrical installation shall have the appropriate wire
size matching the requirement of the loads and the
following table gives the recommendations for different
types of loads:
For the mains cable
For installation wiring
For main earth or mam equipotential wire
Underground installation and installation in cable trench,
feeders between buildings, etc
Installation in plant rooms, switch rooms etc, on cable tray
or ladder or protected trench, where risk of mechanical
damage to cable does not exist.
Tough plastic sheathed (TPS) cable
Tough plastic sheathed (TPS) cables
Poly vinyl chloride (PVC) insulated conduit
wire
PVC insulated, PVC sheathed armored
cables or XLPE insulated, PVC sheathed
cables armoured cables
PVC insulated, PVC sheathed or XLPE
insulated, PVC sheathed unarmoured cables
S.8.5.2 Circuit wire sizes
Recommended minimum wire sizes for various circuits is given below:
SI
No.
Circuits
Minimum Wire Size
Wire Colour
0)
(2)
(3)
(4)
i)
1-way lighting
2 + E cable wires
1.5 mm2
Red-Black-Green or
Green/Y ellow
ii)
2-way lighting control (straps
between the 2 switches)
3 wire cable
1.5 mm2
Red-White-Blue
iii)
Storage water heaters up to 3 kW
2 + E cable
2.5 mm2 (stranded conductors)
Red-Black-Green or
Green/Yellow
iv)
Storage water heaters between
3 kW and 6 kW
2 + E cable
4 mm2 (stranded conductors)
Red-Black-Green or
Green/Y ellow
v)
Socket-outlets and permanent
connection units
2 + E cable
2.5 mm2 (stranded conductors)
Red-Black-Green or
Green/Yellow
VI)
Submains to garages or out
buildings
2 + E cable
2.5 mm' (stranded conductors)
Red-Black-Green or
Green/Y ellow
.
44
NATIONAL BUILDING CODE OF INDIA 2016
Circuits
SI
No.
Minimum Wire Size
Wire Colour
0) _ (2) _
vii) Cooking hobs
viii) Separate ovens
ix) Electric range
x) Mains
xi) Main equipotential bonding wire
xii) Main earth wire
(3)
2 + E cable
1.5 mm"
2 + E cable
4 mm2 (stranded conductors)
2 + E cable
6 mm2 (stranded conductors)
2 wire cable
16 mm2 (stranded conductors)
Conduit wire
4 mm2 (stranded conductors)
Conduit wire
6 mm2 (stranded conductors)
_ (4)
Red-Black-Green or
Green/Yellow
Red-Black- Green or
Green/Yellow
Red-Black
Green or Green/Y ellow
Green or Green/Yellow
NOTES
1 2 + E is also known as twin and earth.
2 Earth wire can be as per the following:
a) Green/Yellow throughout their length with, in addition, light blue markings at the terminations, or
b) Light blue throughout their length with, in addition, green/yellow markings at the terminations.
3 The above sizes are recommendatory and shall be modified as per voltage drop, starting current, distance from DB, etc.
5.8.6 Requirements for
Underground Cables
Physical Protection of
SI
No.
Protective
Element
Specifications
(1)
(2)
(3)
i)
Bricks
(a) 100 mm minimum
width
(b) 25 mm thick
(c) sand cushioning 100
mm and sand cover
100 mm
ii)
Concrete slabs
At least 50 mm thick
iii)
Plastic slabs
(polymeric
cover strips)
Fibre reinforced
plastic
At least 1 0 mm thick,
depending on properties
and has to be matched
with the protective
cushioning and cover
iv)
PVC conduit or
PVC pipe or
stoneware pipe
or hume pipe
The pipe diameter
should be such so that
the cable is able to
easily slip down the pipe
v)
Galvanized pipe
The pipe diameter
should be such so that
the cable is able to
easily slip down the pipe
The trench shall be backfilled to cover the cable initially
by 200 mm of sand fill; and then a plastic marker strip
shall be put over the full length of cable in the trench.
The marker signs shall be provided where any cable
enters or leaves a building. This will identify that there
is a cable located underground near the building. The
trench shall then be completely filled. If the cables rise
above ground to enter a building or other structure, a
mechanical protection such as a GI pipe or PVC pipe
for the cable from the trench depth to a height of 2.0 m
above ground shall be provided.
5.9 Lighting and Levels of Illumination
5.9.1 General
Lighting installation shall take into consideration many
factors on which the quality and quantity of artificial
lighting depends. Recent practice in illumination is to
provide the required illumination with a large number
of light sources (not of higher illumination level) instead
of fewer number of light sources of higher illumination
level, to produce higher uniformity in illumination level.
Now a wide variety of light sources, such as, fluorescent
lamps [tubular (TL) and compact (CFL)], light emitting
diodes (LED) and induction lighting are available in
addition to the incandescent lamps (GLS and halogen),
for application in buildings. Most of them are
competitive when applied in the segment for which a
particular type is well suited.
With the increase in energy costs and awareness of the
need to conserve energy for the protection of the
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
45
environment, lighting design is becoming complex.
With the developments in the types of light sources
and theii contiol systems now available, lighting design
goes with the concept of better light with less energy
and least impact on environment.
Automatic lighting control schemes may be considered
to have eificient utilization of lights. Automatic controls
can take care of the switching oft when the space served
has no activity or is illuminated by daylight.
5.9.2 Electrical Installations for Lighting
The concepts or needs of energy conservation today
require more lights to be provided so that different sets of
lights are used to light up the area of activity to the required
higher level of lighting needed for the activity and provide
a general minimum background level of lighting. Any
space requires two or three different combination of
lighting sets associated with the activity and this may
require the wiring to be provided to accommodate the
lighting groups in different circuits with group controls,
automatic controls and remote controls.
Availability of LED lights with a wide range from 1 W
to 100 W allows designers to provide spot task lighting
of a high illumination level combined with a general
space lighting of low illumination. As light follows the
inverse square law, provision of the light source close
to the task reduces the energy need.
Lighting demand for buildings should be considered
as per type of building. Where nothing is specified, for
lighting demand of any type of building a maximum of
13 W/m2 of all built-up areas including balconies.
Covered parking areas may be considered at 3.23 W/m2
including balconies, service areas, corridors, etc, may
be considered with very basic diversity of 80 percent
to 100 percent. Power requirements shall be considered
at least 55 W/m2 with an overall diversity not exceeding
50 percent. These shall be excluding defined loads such
as lifts, plumbing system, fire fighting systems,
ventilation requirement, etc.
While incandescent lamps (GLS or halogen) does not
require any control gear, other light sources such as
tubular fluorescent lamps, compact fluorescent lamps,
mercury vapour lamps, sodium vapour lamps, metal
halide lamps and light emitting diode (LED) lamps have
non-linear characteristics and require specifically made
control gear for each type of lamp for their proper
operation. In some cases the control gear is integral
with the lamp and in some it is with light fitting and in
some it is external. The electrical installation and wiring
has to take this into account and provide appropriate
space for such control gear. There will be heat emission,
introduction of harmonics etc, and they also consume
some energy. The electrical and lighting system design
has to keep this aspect in the wiring design and
46
installation. Control gear contributes or influences
energy conservation significantly and due care should
be taken to ensure a proper choice.
5.9.3 Principles of Lighting
When considering the function of artificial lighting,
attention shall be given to the following principle
characteristics before designing an installation:
a) Illumination and its uniformity;
b) Special distribution of light. This includes a
reference to the composition of diffused and
directional light, direction of incidence, the
distribution of luminances and the degree of
glare;
c) Colour of the light and colour rendition;
d) Natural light sources, if possible such as light
tubes; and
e) System wattage of the luminaire proposed.
5.9.4 The variety of purposes which have to be kept in
mind while planning the lighting installation may be
broadly grouped as:
a) Industrial buildings and processes;
b) Offices, schools and public buildings;
c) Surgeries and hospitals; and
d) Hostels, restaurants, shops and residential
buildings.
5.9.4. 1 It is important that appropriate levels of
illumination for these and the types and positions of
fittings determined to suit the task and the disposition
of the working planes.
5.9.5 For detailed requirements for lighting and lighting
design and installations, reference shall be made to
National Lighting Code. For specific requirements for
lighting of special occupancies, reference shall be made
to good practice [8-2(30)] and the National Lighting
Code.
5.9.6 Energy Conservation
Energy conservation may be achieved by using the
following:
a) Energy efficient lamps, chokes, ballast, etc,
for lighting equipment.
b) Efficient switching systems such as remote
sensors, infrared switches, master switches,
occupancy sensors, light sensors, light
automation, remote switches, etc for switching
ON and OFF of lighting circuits.
c) Properly made/connected joints/contacts to
avoid loose joints leading to loss of power.
5.10 In locations where the system voltage exceeds
650 V, as m the case of industrial locations, for details
of design and construction of wiring installation,
NATIONAL BUILDING CODE OF INDIA 2016
reference may be made to good practice [8-2(1 1)].
5.11 Guideline for Electrical Layout in Residential
Buildings
For guidelines for electrical installation in residential
buildings, reference may be made to good practice
[8-2(31)].
A typical distribution scheme in a residential building
with separate circuits for lights and fans and for power
appliances is given in Fig. 3.
5.12 For detailed information regarding the installation
of different electrical equipment, reference may be
made to good practice [8-2(32)].
6 WIRING
6.1 Provision for Maximum Load
All conductors, switches and accessories shall be of
such size as to be capable of carrying, without their
respective ratings being exceeded, the maximum
current which will normally flow through them.
6.1.1 Estimation of Load Requirements
In estimating the current to be carried by any conductor
the following ratings shall be taken, unless the actual
values are known or specified for these elements:
SI
No.
(1)
Element
(2)
Rating
W
(3)
i)
Incandescent lamp
60
ii)
Ceiling fan
60
iii)
Table fan
60
iv)
6 A socket outlet
100, unless the
actual value of
loads are specified
v)
1 6 A socket outlet
1 000, unless the
actual value of
loads are specified
vi)
Fluorescent light:
Length :
a) 600 mm
25
b) 1 200 mm
50
c) 1 500 mm
90
vii)
High pressure
According to their
mercury vapour
capacity, control
(HPMV) lamps, high
gear losses shall be
pressure sodium
also considered as
vapour (HPSV)
lamps
applicable
viii)
Compact fluorescent
lamp (CFL)
20
ix)
Light emitting diode
(LED)
10
SI
No.
(1)
Element
(2)
Rating
W
(3)
x)
Exhaust fan
50
XI)
Geyser (storage type)
2 000
xii)
Geyser (instant)
3 000
xiii)
Computer point
150
xiv)
Computer (laptop)
50
xv)
Printer, laser
1 500
xvi)
Printer, inkjet
70
xvii)
Kitchen outlet
1 500
xviii)
Air conditioner:
1 TR
1 250
1.5 TR
1 875
2 TR
2 500
2.5 TR
3 200
6.1.2 Electrical installation in a new building shall
normally begin immediately on the commencement of
the main structural building work and before finishing
work such as plastering has begun except in the case of
surface wiring which can be carried out after the plaster
work. Usually, no installation work should start until
the building is reasonably weatherproof, but where
electric wiring is to be concealed within the structures
as may be the case with a reinforced concrete building,
the necessary conduits and ducts shall be positioned
firmly by tying the conduit to the reinforcement before
concreting. Care should be taken to avoid use of
damaged conduit or ducts, the conduits end shall be
given suitable anti-corrosive treatment and holes
blocked off by putties or caps to protect conduits from
getting blocked. All conduit openings and junction box
openings, etc shall be properly protected against entry
of mortar, concrete, etc, during construction.
6.2 Selection of Size of Conductors
The size of conductors of circuits shall be so selected
that the drop in voltage from consumer’s terminals in a
public supply (or from the bus-bars of the main
switchboard controlling the various circuits in a private
generation plant) to any point on the installation does
not exceed three percent of the voltage at the consumer’s
terminals (or at two bus-bars as these may be) when the
conductors are carrying the maximum current under the
normal conditions of service. The overall voltage drop
from the transformer end to consumer’s final distribution
board shall not exceed six percent.
6.2.1 If the cable size is increased to reduce voltage
drop in the circuit, the rating of the cable shall be
sufficient to carry the current which the circuit is
designed for. In each circuit or sub-circuit the fuse/
circuit-breaker shall be selected to match the current
rating of the circuit to ensure the desired protection.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
47
6A SWITCH
Fig. 3 Wiring Diagram for a Typical Distribution Scheme in a Residential Building Flat
48
NATIONAL BUILDING CODE OF INDIA 2016
6.3 Branch Switches
Where the supply is derived from a three-wire or four-
wire source, and distribution is done on the two-wire
system, all branch switches shall be placed in the outer
or live conductor of the circuit and no single phase
switch or protective device shall be inserted in the
middle wire, earth or earthed neutral conductor of the
circuit. Single-pole switches (other than for multiple
control) carrying not more than 1 6 A may be of tumbler
type or flush type which shall be on when the handle or
knob is down.
6.4 Layout and Installation Drawing
6.4.1 The electrical layout should be drawn indicating
properly the locations of all outlets, such as, lamps,
fans, appliances (both fixed and movable) and motors
and best suit for wiring.
6.4.2 All runs of wiring and the exact positions of all
points of switch-boxes and other outlets shall be first
marked on the plans of the building and approved by
the Engineer-in-Charge or the owner before actual
commencement of the work.
6.4.3 Industrial layout drawings should indicate the
relative civil and mechanical details.
6.4.4 Layout of Wiring
The layout of wiring should be designed keeping in
view disposition of the lighting system to meet the
illumination levels. All wirings shall be done on the
distribution system with main and branch distribution
boards at convenient physical and electrical load
centres. All types of wiring, whether concealed or
unconcealed should be as near the ceiling as possible.
In all types of wirings due consideration shall be given
for neatness and good appearance.
6.4.5 Balancing of circuits in three-wire or poly-phase
installation shall be arranged beforehand. Proper
balancing can be done only under actual load
conditions. Conductors shall be so enclosed in earthed
metal or incombustible insulating material that it is not
possible to have ready access to them. Means of access
shall be marked to indicate the voltage present.
Where terminals or other fixed live parts between which
a voltage exceeding 250 V exists are housed in separate
enclosures or items of apparatus which, although
separated are within reach of each other, a notice shall
be placed in such a position that anyone gaining access
to live parts is warned of the magnitude of the voltage
that exists between them.
Where loads are single phase, balancing should be for
the peak load condition based on equipment usage.
Facility for change should be built into the distribution
design.
NOTE — The above requirements apply equally to three-phase
circuits in which the voltage between lines or to earth exceeds
250 V and to groups of two or more single-phase circuits,
between which medium voltage may be present, derived
therefrom. They apply also to 3-wire d.c. or 3-wire single-phase
a.c. circuits in which the voltage between lines or to earth
exceeds 250 V and to groups of 2-wire circuits, between which
medium voltage may be present, derived there from.
6.4.6 Medium voltage wiring and associated apparatus
shall comply, in all respects, with the requirements of
Regulation 35, 36, 37, 40, 41 and 42 of Central
Electricity Authority (Measures Relating to Safety and
Electricity Supply) Regulations , 2010, as amended from
time-to-time (see Annex B).
6.5 Conductors and Accessories
6.5.1 Conductors
Conductors for all the internal wiring shall be of copper.
Conductors for power and lighting circuits shall be of
adequate size to carry the designed circuit load without
exceeding the permissible thermal limits for the
insulation. For final section wiring to larger loads, the
current carrying capacity will preside. The conductor
size shall also be based on the voltage drop in the line so
as to provide a terminal voltage not below the prescribed
voltage requirement.
The conductor for final sub-circuit for fan and light wiring
shall have a nominal cross-sectional area not less than
1 .50 mm2 copper. The cross-sectional area of conductor
for power wiring shall be not less than 2.5 mm2 copper.
The minimum cross-sectional area of conductor of
flexible cord shall be 1 .50 mm2 copper.
In existing buildings where aluminum wiring has been
used for internal electrification, changeover from
aluminum conductor cables to copper conductor cables
is recommended as it has been found that aluminum
conductors below 1 0 mm2 size pose a number of hazards.
NOTE — It is advisable to replace wiring, which is more than
30 years old as the insulation also would have deteriorated,
and will be in a state to cause failure on the slightest of
mechanical or electrical disturbance.
6.5.2 Flexible Cables and Flexible Cords
Flexible cables and cords shall be of copper and
stranded and protected by flexible conduits or tough
rubber or PVC sheath to prevent mechanical damage.
6.5.3 Cable Ends
When a stranded conductor having a nominal sectional
area less than 6 mm2 is not provided with cable sockets,
all strands at the exposed ends of the cable shall be
soldered together or crimped using suitable sleeve or
ferrules.
6.5.4 Special Risk
Special forms of construction, such as flameproof
49
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
enclosures, shall be adopted where there is risk of fire
or explosion.
6.5.5 Connection to Ancillary Buildings
Unless otherwise specified, electric connections to
ancillary buildings, such as out-houses, garages, etc,
adjacent to the main building and when no roadway
intervenes shall be taken in an earthed GI pipe or heavy
duty PVC or HDPE pipe of suitable size. This pipe can
be taken either underground or over ground, however,
in latter case, its height from the ground shall not be
less than 5.8 m. This applies to both runs of mains or
sub-mains or final sub-circuit wiring between the
buildings.
6.5.6 Expansion Joints
Distribution boards shall be so located that the conduits
shall not normally be required to cross expansion joints
in a building. Where such crossing is found to be
unavoidable, special care shall be taken to ensure that
the conduit runs and wiring are not in any way put to
strain or damaged due to expansion of building
structure. Anyone of the following standard methods
of connection at a structural expansion joint shall be
followed:
a) Flexible conduit shall be inserted at place of
expansion joint.
b) Oversized conduit overlapping the conduit.
c) Expansion box.
Supports and flexible joints shall be of same
requirement as the rising main/bus duct in so far as
resistance to seismic forces is concerned. This is further
important when rising mains and bus-ducts cross
expansion joints.
6.5.7 Low Voltage ( Types of Wires/Cables)
Low voltage services utilizes various categories of
cables/wires, such as fibre optic cable, co-axial,
category cable, etc. These shall be laid at least at a
distance of 3 00 mm from any power wire or cable. The
distance may be reduced only by using completely
closed earthed metal trunking with metal separations
for various kind of cable. Special care shall be taken to
ensure that the conduit runs and wiring are laid properly
for low voltage signal to flow through it.
The power cable and the signal or data cable may run
together under floor and near the equipment. However,
separation may be required from the insulation aspect,
if the signal cable is running close to an un-insulated
conductor carrying power at high voltage. All types of
signal cables are required to have insulation level for
withstanding 2 lcV impulse voltage even if they are
meant for service at low voltage.
6.6 Joints and Looping Back
6.6.1 Where looping back system of wiring is specified,
the wiring shall be done without any junction or
connector boxes on the line. Where joint box system is
specified, all joints in conductors shall be made by
means of suitable mechanical connectors in suitable
joint boxes. Whenever practicable, only one system
shall be adopted for a building, preferably a looping
back system.
6.6.2 In any system of wiring, no bare or twist joints
shall be made at intermediate points in the through run
of cables unless the length of a final sub-circuit, sub-
main or main is more than the length of the standard
coil as given by the manufacturer of the cable. If any
jointing becomes unavoidable such joint shall be made
through proper cutouts or through proper junction boxes
open to easy inspection, but in looping back system no
such junction boxes shall be allowed.
6.6.3 Joints are a source of problems in reliability and
are also vulnerable to fire. They should be avoided or
at least minimized. They should under no circumstance
exceed more than one to two in total length and distance
between two shall not be less than 5 m. Joint should
not be used as tap-off for multiple feeders. Where joints
in cable conductors or bare conductors are necessary,
they shall be mechanically and electrically sound. Joints
in non-flexible cables shall be accessible for inspection;
provided that this requirement shall not apply to joints
in cables buried underground, or joints buried or
enclosed in non-combustible building materials. Joints
in non-flexible cables shall be made by soldering,
brazing, welding or mechanical clamps, or be of the
compression type; provided that mechanical clamps
shall not be used for inaccessible joints buried or
enclosed in the building structure. All mechanical
clamps and compression type sockets shall securely
retain all the wires of the conductors. Any joint in a
flexible cable or flexible cord shall be effected by means
of a cable coupler.
For flexible cables for small loads less than 1 kW, while
it is desirable to avoid joints, if unavoidable, joints may
be made either by splicing by a recognized method or
by using a connector and protecting the joint by suitable
insulating tape or sleeve or straight joint. For
application of flexible cable for loads of 1 kW or more,
if joint is unavoidable, crimped joint is preferred.
Spliced joint should not be used for large loads.
There are different standard joints, such as epoxy resin
based joint, heat shrinkable plastic sleeve joint, etc,
and each one has its advantage and disadvantage.
Selection has to be made on the basis of application,
site conditions and availability of skilled licensed
workmen trained in the application of the particular
type of joint.
50
NATIONAL BUILDING CODE OF INDIA 2016
6.6.4 Every joint in a cable shall be provided with
insulation not less effective than that of the cable cores
and shall be protected against moisture and mechanical
damage. Soldering fluxes which remain acidic or
corrosive at the completion of the soldering operation
shall not be used.
For joints in paper-insulated metal-sheathed cables, a
wiped metal sleeve or joint box, filled with insulating
compound, shall be provided.
Where an aluminum conductor and a copper conductor
are joined together, precautions shall be taken against
corrosion and mechanical damage to the conductors.
6.6.5 Pull at Joints and Terminals
Ever)' connection at a cable termination shall be made
by means of a terminal, soldering socket, or
compression type socket and shall securely contain and
anchor all the wires of the conductor, and shall not
impose any appreciable mechanical strain on the
terminal or socket.
Flexible cords shall be so connected to devices and to
fittings that tension is not transmitted to joints or
terminal screws. This shall be accomplished by a knot
in the cord, by winding with tape, by a special fitting
designed for that purpose, or by other approved means
which can prevent a pull on the cord from being directly
transmitted to joints or terminal screws.
6.7 Passing Through Walls and Floors
6.7.1 Where wires/cables are required to pass through
walls, care shall be taken to see that wires/cables pass
freely through protective pipe or box and that the wires
pass through in a straight line without any twist or cross
in wires.
One of the following methods shall be employed for
laying wires/cables:
a) Conduit wiring system ( see 6.10) — The
conductor shall be carried either in a rigid steel
conduit or a rigid non-metallic conduit
conforming to accepted standards [8-2(33)].
The conduits shall be colour coded as per the
purpose of wire carried in the same. The
recommended colour coding may be in form
of bands of colour ( 1 00 mm thick, with centre
to centre distance of 300 mm) or coloured
throughout. The colour scheme may be as
follows:
Conduit Type Colour Scheme
Power conduit Black
Security conduit Blue
Fire alarm conduit Red
Low voltage conduit Brown
UPS conduit Green
Conduit wiring system shall comply with
accepted standards [8-2(34)]. The number of
insulated conductors that can be drawn into
rigid conduit is given in Tables 1 (see Table
1A for rigid steel conduits and Table IB for
rigid non-metallic conduits).
b ) Cable trunking/cable ways ( see 6.11) — Cable
trunking/cable ways system should be used
when number of wires/small cable sizes to be
laid is more than the conduit capacity. Care
should be taken to have space in the trunking
system to minimize heating of wires and to
provide identification of the different circuits.
Cable trunking or ducting system shall comply
with accepted standards [8-2(35)].
c) Tray and ladder rack — As tray provides
continuous support, unless mounted on edge
or in vertical runs (when adequate strapping
or clipping is essential), the mechanical
strength of supported cable is not as important
as with ladder-racking or structural support
methods. Consequently, tray is eminently
suitable for the smaller unarmoured cabling
while ladder racks call for armoured cables
or larger unarmoured cables as they provide
the necessary strength to avoid sagging
between supports. Both tray and ladder racks
are provided with accessories to facilitate
changes of route, and they provide nc
difficulty in this respect on vertical runs.
Cable tray/ladder racks and support systems
shall be installed in such a way that the
deflection between the spans shall be less than
1 percent of the span.
Power cables running in cable ladders both
horizontal and vertical shall be fixed with
proper clamps which can withstand the
mechanical force created on the cable in case
of short circuit current. The complete
installation consisting of cables, ladders,
clamps, Udder supports and fixtures shall also
withstand the mechanical force of short circuit
current. Only one layer of power cable shall
be laid in a ladder. The minimum space
between two cables shall be equal to the
diameter of the biggest cable.
Cable tray and ladder system shall comply
with IEC 61537:2006 ‘Cable management —
Cable tray systems and cable ladder systems’
(under publication as an adopted Indian
Standard).
6.7.2 Insulated conductors while passing through floors
shall be protected from mechanical injury by means of
rigid steel/non-metal conduit or by mechanical
protection up to a height not less than 1 .5 m above the
PART 8 BUILDING SERV ICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
51
floor and flush with the ceiling below. These steel
conduits shall be earthed and securely bushed.
Power outlets and wiring in the floor shall be generally
avoided. If not avoidable, false floor trunking or metal
floor trunking should be used. Power sockets of
adequate IP/IK rating shall be used.
False floor shall be provided where density of
equipment and interconnection between different pieces
of equipment is high. Examples are, mainframe
computer station, telecommunication switch rooms, etc.
Floor trunking shall be used in large halls, convention
centres, open plan offices, laboratory, etc.
In case of floor trunking, drain points/weep holes shall
be provided within the trunking for installation for
conventional centres, exhibition areas or any other place
where water may spill into the trunking, as there might
be possibility of water seepage in the case of wiring
passing through the floors. Proper care should be taken
for providing suitable means of draining of water.
Possibility of water entry exists from floor washing,
condensation in some particular weather and indoor
temperature conditions. At the design stage, these
aspects shall be assessed and an appropriate means of
avoiding, or reducing, and draining method shall be
built in. Floor trunking outlets shall be suitably IP rated
for protection against dust and water.
Floor outlet boxes are generally provided for the use
of appliances, which require a signal, or communication
connection. The floor box and trunking system should
cater to serve both power distribution and the signal
distribution, with appropriate safety and non¬
interference.
6.7.3 Where a wall tube passes outside a building so as
to be exposed to weather, the outer end shall be bell¬
mouthed and turned downwards and properly bushed
on the open end.
6.8 Wiring of Distribution Boards
6.8.1 All connections between r Aces of apparatus or
between apparatus and terminals on a board shall be
neatly arranged in a definite sequence, following the
arrangements of the apparatus mounted thereon,
avoiding unnecessary crossings.
6.8.2 Cables shall be connected to a terminal only by
soldered or welded or crimped lugs using suitable
sleeve, lugs or ferrules unless the terminal is of such a
form that it is possible to securely clamp them without
the cutting away of cables stands. Cables in each circuit
shall be bunched together.
6.8.3 All bare conductors shall be rigidly fixed in such
a manner that a clearance of at least 25 mm is
maintained between conductors or opposite polarity or
phase and between the conductors and any material
other than insulation material.
6.8.4 If required, a pilot lamp shall be fixed and
connected through an independent single pole switch
and fuse to the bus-bars of the board. Teads connecting
bus-bars to any instrument or indicating lamp or an
outgoing connection switch or breaker face the same
fault current that is applicable to the bus-bar and as
such should be provided with a fuse capable of handling
the prospective fault current.
6.8.5 In a hinged type board, the incoming and outgoing
cables shall be fixed at one or more points according
to the number of cables on the back of the board leaving
suitable space in between cables, and shall also, if
possible, be fixed at the corresponding points on the
switchboard panel. The cables between these points
shall be of such length as to allow the switchboard panel
to swing through an angle of not less than 90° and cables
arranged and clamped in such a manner that the cables
do not face bending, but only face a twist, when the
hinged door is opened. The circuit breakers in such
cases shall be accessible without opening the door of
distribution board. Also, circuit breakers or any other
equipment (having cable size more than 1 .5 mm2 multi¬
strand wire) shall not be mounted on the door.
NOT E — Use of hinged type boards is discouraged, as these
boards lead to deterioration of the cables in the hinged portion,
leading to failures or even fire.
6.8.6 Wires terminating and originating from the
protective devices shall be properly lugged and taped.
6.9 PVC-Sheathed Wiring System
6.9.1 General
Wiring with PVC-sheathed cables may be used for
temporary installations for medium voltage installation
and may be installed directly under exposed conditions
of sun and rain or damp places.
6.9.2 PVC Clamps/ PVC Channel
The clamps shall be used for temporary installations
of 1-3 sheathed wires only. The clamps shall be fixed
on wall at intervals of 1 00 mm in the case of horizontal
runs and 150 mm in the case of vertical runs.
PVC channel shall be used for temporary installations
in case more than 3 wires or wires or unsheathed wires.
The channel shall be clamped on wall at intervals not
exceeding 300 mm. PVC clamps/PVC channel shall
conform to accepted standards.
6.9.3 Protection of PVC-Sheathed Wiring from
Mechanical Damage
a) In cases where there are chances^of any
damage to the wirings, such wirings shall be
• • • • * .
NATIONAL BUILDING CODE OF INDIA 2016
52
covered with sheet metal protective covering,
the base of which is made flush with the plaster
or brickwork, as the case may be, or the wiring
shall be drawn through a conduit complying
with all requirements of conduit wiring system
(see 6.10).
b) Such protective coverings shall in all cases
be fitted on all down-drops within 1 .5 m from
the floor.
6.9.4 Bends in Wiring
The wiring shall not in any circumstances be bent so as
to form a right angle but shall be rounded off at the
comers to a radius not less than six times the overall
diameter of the cable.
6.9.5 Passing Through Floors
All cables taken through floors shall be enclosed in an
insulated heavy gauge steel conduit extending 1 .5 m
above the floor and flush with the ceiling below, or by
means of any other approved type of metallic covering.
The ends of all conduits or pipes shall be neatly bushed
with porcelain, wood or other approved material.
6.9.6 Passing Through Walls
The method to be adopted shall be according to good
practice. There shall be one or more conduits of
adequate size to carry the conductors [ see 6.10.1(a)],
The conduits shall be neatly arranged so that the cables
enter them straight without bending.
6.9.7 Stripping of Outer Covering
While cutting and stripping of the outer covering of
the cables, care shall be taken that the sharp edge of
the cutting instrument does not touch the rubber or
P VC-sheathed insulation of conductors. The protective
outer covering of the cables shall be stripped off near
connecting terminals, and this protective covering shall
be maintained up to the close proximity of connecting
terminals as far as practicable. Care shall be taken to
avoid hammering on link clips with any metal
instruments, after the cables are laid. Where junction
boxes are provided, they shall be made moisture-proof
with an approved plastic compound.
6.9.8 Painting
If so required, the tough rubber-sheathed wiring shall,
after erection, be painted with one coat of oil-less paint
or distemper of suitable colour over a coat of oil-less
primer, and the PVC-sheathed wiring shall be painted
with a synthetic enamel paint of quick drying type.
6.10 Conduit Wiring System
Conduit wiring system shall comply with accepted
standards [8-2(34)]. Requirements relating to conduit
wiring system with rigid steel and non-metallic conduits
shall be as per 6.10.1 to 6.10.3.
6.10.1 Surface Conduit Wiring System with Rigid Steel
Conduits
a) Type and size of conduit — All conduit pipes
shall conform to accepted standards [8-2(36)],
finished with galvanized or enamelled surface.
All conduit accessories shall be of threaded
type and under no circumstance pin grip type
or clamp type accessories be used. No steel
conduit less than 16 mm in diameter shall be
used. The number of insulated conductors that
can be drawn into rigid steel conduit is given
in Tables 1A.
b) Bunching of cables — Unless otherwise
specified, insulated conductors of a.c. supply
and d.c. supply shall be bunched in separate
conduits. For lighting and small power outlet
circuits phase segregation in separate conduits
is recommended.
c) Conduit joints — Conduit pipes shall be joined
by means of screwed couplers and screwed
accessories only [see 8-2(37)]. In long distance
straight runs of conduit, inspection type
couplers at reasonable intervals shall be
provided or running threads with couplers and
jam-nuts (in the latter case the bare threaded
portion shall be treated with anti-corrosive
preservative) shall be provided. Threaded on
conduit pipes in all cases shall be between 1 1
mm and 27 mm long sufficient to accommodate
pipes to full threaded portion of couplers or
accessories. Cut ends of conduit pipes shall
have no sharp edges or any burrs left to avoid
damage to the insulation of conductors while
pulling them through such pipes.
d) Protection against dampness — In order to
minimize condensation or sweating inside the
tube, all outlets of conduit system shall be
properly drained and ventilated, but in such a
manner as lo prevent the entry of insects as
far as possible.
e) Protection of conduit against rust — The
outer surface of the conduit pipes, including
all bends, unions, tees, conduit system shall
be adequately protected against rust
particularly when such system is exposed to
weather. In all cases, no bare threaded portion
of conduit pipe shall be allowed unless such
bare threaded portion is treated with anti¬
corrosive preservative or covered with suitable
plastic compound.
f) Fixing of conduit — Conduit pipes shall be
fixed by heavy gauge saddles, secured to
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
53
Table 1A Maximum Permissible Number of Single-Core Cables up to and including 1 100 V
that can be Drawn into Rigid Steel Conduits
[Clauses 6.7.1(a) and 6.10.1(a)]
SI Size of Cable
No.
Size of Conduit
mm
Nominal
Number
16
20
25
32
40
50
63
Cross-
and
Number of Cables, Max
Sectional
Diameter
Area
(in mm) of
S
B
S
B
S
B
S
B
S
B
's
B
S
N
B
mm2
Wires
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
i)
1.0
1/1.12°
5
4
7
5
13
10
20
14
ii)
1.5
1/1.40
4
3
7
5
12
10
20
14
_
_
_
_
iii)
2.5
1/1.80
o
J
2
6
5
10
8
18
12
_
3/1.06°
iv)
4
1/2.24
3
2
4
->
J
7
5
12
10
_
7/0.85°
v)
6
1/2.80
2
—
3
2
6
5
10
8
_
7/1.06°
vi)
10
l/3.55* 2)
—
—
2
—
5
4
8
7
_
7/1.40°
—
—
2
—
4
3
6
5
8
6
vii)
16
7/1.70
—
—
- -
—
2
—
4
3
7
6
viii)
25
7/2.24
—
—
—
—
—
—
3
2
5
4
8
6
9
7
ix)
35
7/2.50
—
—
—
—
—
—
2
_
4
3
7
5
8
6
x)
50
19/1.80
—
—
—
—
—
—
—
—
2
—
5
4
6
5
7/3.0072)
NOTES
1 The table shows the maximum capacity of conduits for the simultaneously drawing of cables. The columns headed S apply to runs
of conduit which have distance not exceeding 4.25 m between draw-in boxes, and which do not deflect from the straight by an angle
of more than 15°. The columns headed B apply to runs of conduit which deflect from the straight by an angle of more than 15°.
2 In case an inspection type draw-in box has been provided and if the cable is first drawn through one straight conduit, then through the
draw-in box, and then through the second straight conduit, such systems may be considered as that of a straight conduit even if the
conduit deflects through the straight by more than 15°.
3 Conductor sizes for cables and wires above and including 2.5 mm2 core size shall be multi-stranded.
° For copper conductors only.
2) For aluminium conductors only.
suitable wood plugs or other plugs with screws
in an approved manner at an interval of not
more than 1 m, but on either side of couplers
or bends or similar fittings, saddles shall be
fixed at a distance of 300 mm from the centre
of such fittings. Conduit fittings shall be
avoided as far as posCbie on conduit system
exposed to weather; where necessary, solid
type fittings shall be used,
g) Bends in conduit — All necessary bends in
the system including diversion shall be done
by bending pipes; or by inserting suitable solid
or inspection type normal bends, elbows or
similar fittings; or fixing cast iron,
thermoplastic or thermosetting plastic material
inspection boxes, whichever is more suitable.
Radius of such bends in conduit pipes shall
be not less than 75 mm. No length of conduit
shall have more than the equivalent of four
quarter bends from outlet to outlet, the bends
at the outlets not being counted.
h) Outlets — All outlets for fittings, switches,
etc, shall be boxes of suitable metal or any
other approved outlet boxes for either surface
mounting or flush mounting system.
j) Conductors — All conductors used in conduit
wiring shall preferably be stranded. No single¬
core cable of nominal cross-sectional area
greater than 130 mm2 enclosed along in a
conduit and used for alternating current.
k) Erection and earthing of conduit — The
conduit of each circuit or section shall be
completed before conductors are drawn in.
The entire system of conduit after erection
shall be tested for mechanical and electrical
continuity throughout and permanently
connected to earth conforming to the
requirements as already specified by means
of suitable earthing clamp efficiently fastened
to conduit pipe in a workman like manner for
a perfect continuity between each wire and
conduit. Gas or water pipes shall not be used
54
NATIONAL BUILDING CODE OF INDIA 2016
as earth medium. If conduit pipes are liable to
mechanical damage they shall be adequately
protected.
m) Inspection type conduit fittings, such as
inspection boxes, draw boxes, bends, elbows
and tees shall be so installed that they can
remain accessible for such purposes as to
withdrawal of existing cables or the installing
of traditional cables.
6.10.2 Recessed Conduit Wiring System with Rigid Steel
Conduit
Recessed conduit wiring system shall comply with all
the requirements for surface conduit wiring system
specified in 6.10.1 (a) to 6.10.1 (k) and in addition,
conform to the requirements specified below:
a) Making of chase — The chase in the wall shall
be neatly made and be of ample dimensions
to permit the conduit to be fixed in the manner
desired. In the case of buildings under
construction, chases shall be provided in the
wall, ceiling, etc, at the time of their
construction and shall be filled up neatly after
erection of conduit and brought to the original
finish of the wall. In case of exposed brick/
rubble masonry work, special care shall be
taken to fix the conduit and accessories in
position along with the building work.
b) Fixing of conduit in chase — The conduit pipe
shall be fixed by means of staples or by means
of saddles not more than 600 mm apart. Fixing
of standard bends or elbows shall be avoided
as far as practicable and all curves maintained
by bending the conduit pipe itself with a long
radius which will permit easy drawing-in of
conductors. All threaded joints of rigid steel
conduit shall be treated with preservative
compound to secure protection against rust.
c) Inspection boxes — Suitable inspection boxes
shall be provided to permit periodical
inspection and to facilitate removal of wires,
if necessary. These shall be mounted flush with
the wall. Suitable ventilating holes shall be
provided in the inspection box covers. The
minimum sizes of inspection boxes shall be
75 mm x 75 mm.
d) Types of accessories to be used — All outlet,
such as switches and wall sockets, may be
either of flush mounting type or of surface
mounting type, as given below:
1) Flush mounting type — All flush
mounting outlets shall be of cast-iron or
mild steel boxes with a cover of insulating
material or shall be a box made of a
suitable insulating material. The switches
and other outlets shall be mounted on such
boxes. The metal box shall be efficiently
earthed with conduit by a suitable means
of earth attachment.
2) Surface mounting type — If surface
mounting type outlet box is specified, it
shall be of any suitable insulating material
and outlets mounted in an approved
manner.
The switches/socket outlets shall have
adequate IP rating for various utilizations.
6.10.3 Conduit Wiring System with Rigid Non-Metallic
Conduits
Rigid non-metallic conduits are used for concealed
conduit wiring.
6.10.3.1 Type and size
All non-metallic conduits used shall conform to
accepted standards [8-2(38)] and shall be used with
the corresponding accessories {see accepted standards
[8-2(3 9)] } . The conduits shall be circular or rectangular
cross-sections.
6.10.3.2 Bunching of cables
Conductors of a.c. supply and d c. supply shall be
bunched in separate conduits. For lighting and small
power outlet circuits phase segregation in separate
circuits is recommended. The number of insulated
cables that may be drawn into the conduits are given in
Table 1 B. In Table IB, the space factor does not exceed
40 percent.
6.10.3.3 Conduit Joints
Conduits shall be joined by means of couplers. Where
there are long runs of straight conduit, inspection type
couplers shall be provided at intervals. For conduit
fittings and accessories reference may be made to the
good practice [8-2(39)].
6.10.3.4 Fixing of conduit in chase
The conduit pipe shall be fixed by means of stapples
or by means of non-metallic saddles placed at not more
than 800 mm apart or by any other approved means of
fixing. Fixing of standard bends or elbows shall be
avoided as far as practicable and all curves shall be
maintained by sending the conduit pipe itself with a
long radius which will permit easy drawing in of
conductors. At either side of bends, saddles/stapples
shall be fixed at a distance of 150 mm from the centre
of bends.
6.10.3.5 Inspection boxes
Suitable inspection boxes to the nearest minimum
requirements shall be provided to permit periodical
inspection and to facilitate replacement of wires, if
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
Table IB Maximum Permissible Number of 250 V Gra e Single-Core Cables that may be
Drawn into Rigid Non-Metallic Conduits
[Clauses 6.7.1(a) and 6.10.3.2]
SI
Sizes of Cable
Size of Conduit
No.
mm
- - -
''S
^ —
Nominal Cross-
Number and
16
20
25
32
40
50
Sectional Area
Diameter (in mm)
Number of Cables, Max
mm2
of Wires
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
0
ii)
1.0
1/1.12°
5
7
13
20
—
—
1.5
1/1.40
4
6
10
14
—
- -
in)
2.5
(1/1.80)
[3/1.06"]
3
5
10
14
14
IV)
4
(1/2.24)
[7/0.85°]
2
3
6
10
11
v)
6
(1/2.80)
[7/1.40"]
—
2
5
9
Vi)
10
[l/3.552)]
[7/1.40"]
—
4
7
9
12
vii)
16
7/1.70
—
—
2
4
5
viii)
25
7/2.24
—
—
—
2
2
6
ix)
35
7/2.50
—
—
—
—
2
5
x)
50
7/3.002)
—
—
—
—
2
5
19/1.80
—
—
—
—
2
3
" For copper conductors only.
2) For aluminium conductors only.
necessary. The inspection/junction boxes shall be
mounted flush with the wall or ceiling concrete. Where
necessary deeper boxes of suitable dimensions shall
be used. Suitable ventilating holes shall be provided in
the inspection box covers, where required.
6.10.3.6 The outlet boxes such as switch boxes,
regulator boxes and their phenolic laminated sheet
covers shall be as per requirements of 6.10.1 (h). They
shall be mounted flush with the wall.
6.10.3.7 Types of accessories to be used
All accessories such as switches, wall sockets, etc, may
be either flush mounting type or of surface mounting
type-
6.10.3.8 Bends in conduits
material are used for surface wiring. The number of
insulated conductors that can be drawn into cable
trunking and ducting system are given in Table 2.
7 FITTINGS AND ACCESSORIES
7.1 Ceiling Roses and Similar Attachments
7.1.1 A ceiling rose or any other similar attachment
shall not be used on a circuit the voltage of which
normally exceeds 250 V.
7.1.2 Normally, only one flexible cord shall be attached
to a ceiling rose. Specially designed ceiling roses shall
be used for multiple pendants.
7.1.3 A ceiling rose shall not embody fuse terminal as
an integral part of it.
Wherever necessary, bends or diversions may be
achieved by bending the conduits or by employing
normal bends, inspection bends, inspection boxes,
elbows or similar fittings. Heat may be used to soften
the conduit for bending and forming joints in case of
plain conduits.
6.10.3.9 Outlets
In order to minimize condensation or sweating inside
the conduit, all outlets of conduit system shall be
properly drained and ventilated, but in such a manner
as to prevent the entry of insects.
6.11 Cable Trunking/Cable Ways
Cable trunking and ducting system of insulating
7.2 Socket-Outlets and Plugs
Each 16 A socket-outlet provided in buildings for the
use of domestic appliances, such as, air conditioner and
water cooler shall be provided with its own individual
fuse, with suitable discrimination with back-up fuse or
miniature circuit-breaker provided in the distribution/
sub-distribution board. The socket-outlet shall not
necessarily embody the fuse as an integral part of it.
7.2.1 Each socket-outlet shall also be controlled by a
switch which shall preferably be located immediately
adjacent thereto or combined therewith.
7.2.2 The switch controlling the socket-outlet shall be
on the live side of the line.
56
NATIONAL BUILDING CODE OF INDIA 2016
Table 2 Maximum Permissible Number of PVC Insulated 650/1 100 V Grade Aluminium/Copper Cable
Conforming to Accepted Standard [8-2(3)] that can be Drawn into Cable Trunking/Cable Ways
( Clause 6.1 1)
SI
Nominal Cross-
No.
Sectional Area
of Conductor
mm2
(1)
(2)
i)
1.5
ii)
2.5
iii)
4
iv)
6
v)
10
Vi)
16
vii)
25
viii)
35
ix)
50
X)
70
10/15 mm x
10 mm
20/15 mm x
10 mm
25/15 mm x
16 mm
32 mm x
16 mm
40 mm x
25 mm
40 mm x
40 mm
(3)
G)
(5)
(6)
(7)
(8)
3
5
6
8
12
18
4
3
2
1
5
4
3
2
6
5
4
3
2
1
9
8
6
5
4
3
2
15
12
9
8
6
5
4
3
2
7.2.3 Ordinary socket-outlet may be fixed at any
convenient place at a height above 200 mm from the
floor level and shall be away from danger of mechanical
injury.
NOTE — In situations where a socket-outlet is accessible to
children, it is necessary to install an interlocked plug and socket
or alternatively a socket-outlet which automatically gets
screened by the withdrawal of plug. In industrial premises
socket-outlet of rating 20 A and above shall preferably be
provided with interlocked type switch.
In case of public buildings, to facilitate operation of
switches/socket-outlets by persons with disabilities
and the elderly, these shall be installed at an accessible
height for reaching and operating, between 800 mm
and 1 100 mm above floor level and shall be located
at a minimum of 600 mm with a preference of
minimum 700 mm, from any internal comer ( see also
B-7 of Part 3 ‘Development Control Rules and
General Building Requirements’ of the Code). They
shall be so fixed so as to be away from danger of
mechanical injury.
NOTE — As an exception, electrical wall socket outlets,
telephone points and TV sockets can be located at a minimum
height of 400 mm above floor level.
7.2.4 In an earthed system of supply, a socket-outlet
with plug shall be of three-pin or five-pin type with the
third or fifth terminal connected to the earth. When
such socket-outlets with plugs are connected to any
current consuming device of metal or any non¬
insulating material or both, conductors connecting such
current-consuming devices shall be of flexible cord with
an earthing core and the earthing core shall be secured
by connecting between the earth terminal of plug and
the body of current-consuming devices.
In industrial premises three-phase and neutral socket-
outlets shall be provided with a earth terminal either of
PART 8 BUILDING SERVICES
pin type or scrapping type in addition to the main pins
required for the purpose.
7.2.5 In wiring installations for residential buildings,
metal clad switch, socket-outlet and plugs shall be used
for power wiring. For industrial and commercial
application socket outlets conforming to accepted
standards [8-2(25)] with suitable circuit breakers shall
be used.
NOTE — A recommended schedule of socket-outlets in a
residential building is given below:
SI
No.
(1)
Location
(2)
Number of
6 A Socket-
Outlets
(3)
Number of
16A
Socket-
Outlets
(4)
i)
Bed room
2 to 6
2
ii)
Living room
2 to 4
2
iii)
Kitchen
2 to 8
2
iv)
Dining room
2 to 4
2
v)
Garage
1
1
vi)
For refrigerator
—
1
vii)
For air conditioner
—
1 for each
viii)
Verandah
1 per
10 m2
1
ix)
Bathroom
1
1
7.3 Lighting Fittings
7.3.1 A switch shall be provided for control of every
lighting fitting or a group of lighting fittings. Where
control at more than one point is necessary as many
two way or intermediate switches may be provided as
there are control points. See also 7.2.3.
7.3.2 In industrial premises, lighting fittings shall be
supported by suitable pipe/conduits, brackets fabricated
from structural steel, steel chains or similar materials
depending upon the type and weight of the fittings.
— SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
57
Where a lighting fitting is supported by one or more
flexible cords, the maximum weight to which the twin
flexible cords may be subjected shall be as follows:
SI
No.
(1)
Nominal Cross-
Sectional Area
of Twin Corel
mm2
(2)
Maximum
Permissible
Weight
kg
(3)
i)
0.5
2
ii)
0.75
3
hi)
1.0
5
IV)
1.5
5.3
v)
2.5
8.8
vi)
4
14.0
7.3.3 No flammable shade shall form a part of lighting
fittings unless such shade is well protected against all
risks of fire. Celluloid shade or lighting fittings shall
not be used under any circumstances.
7.3.4 General and safety requirements for electrical
lighting fittings shall be in accordance with good
practice [8-2(40)].
7.3.5 The lighting fittings shall conform to accepted
standards [8-2(26)].
7.4 Fitting-Wire
The use of fitting-wire shall be restricted to the internal
wiring of the lighting fittings. Where fitting-wire is used
for wiring fittings, the sub-circuit loads shall terminate
in a ceiling rose or box with connectors from which^
they shall be carried into the fittings.
7.5 Lampholders
Lampholders for use on brackets and the like shall be
jn accordance with accepted standards [8-2(41)] and
all those for use with flexible pendants shall be provided
with cord grips. All lampholders shall be provided with
shade carriers. Where centre-contact Edison screw
lampholders are used, the outer or screw contacts shall
be connected to the ‘middle wire’, the neutral, the
earthed conductor of the circuit.
7.6 Outdoor Lamps
External and road lamps shall have weatherproof fittings
of approved design so as to effectively prevent the ingress
of moisture and dust. Flexible cord and cord grip
lampholders shall not be used where exposed to weather.
In verandahs and similar exposed situations where
pendants are used, these shall be of fixed rod type.
7.7 Lamps
All lamps unless otherwise required and suitably
protected, shall be hung at a height of not less than
2.5 m above the floor level. All electric lamps and
accessories shall conform to accepted standards
[8-2(42)]. Following shall also be ensured:
a) Portable lamps shall be wired with flexible
cord. Hand lamps shall be equipped with a
handle of moulded composition or other
materiaf approved for the purpose. Hand
lamps shall be equipped with a substantial
guard attached to the lampholder or handle.
Metallic guards shall be earthed suitably.
b) A bushing or the equivalent shall be provided
where flexible cord enters the base or stem of
portable lamp. The bushing shall be of
insulating material unless a jacketted type of
cord is used.
c) All wiring shall be free from short circuits and
shall be tested for these defects prior to being
connected to the circuit.
d) Exposed live parts within porcelain fixtures
shall be suitably recessed and so located as to
make it improbable that wires will come in
contact with them. There shall be a spacing of
at least 125 mm between live parts and the
mounting plane of the fixture.
7.8 Fans, Regulators and Clamns
7.8.1 Ceiling Fans
Ceiling fans including their suspension shall conform
to accepted standards [8-2(43)] and to the following
requirements:
a) Control of a ceiling fan shall be through its
own regulator as well as a switch in series.
See also 7.2.3.
b) All ceiling fans shall be wired with normal
wiring to ceiling roses or to special connector
boxes to which fan rod wires shall be connected
and suspended from hooks or shackles with
insulators between hooks and suspension rods.
There shall be no joint in the suspension rod,
but if joints are unavoidable then such |oints
shall be screwed to special couplers of 50 mm
minimum length and both ends of the pipes shall
touch together within the couplers, and shall in
addition be secured by means of split pins;
alternatively, the two pipes may be welded. The
suspension rod shall be of adequate strength to
withstand the dead and impact forces imposed
on it. Suspension rods should preferably be
procured along with the fan.
c) Fan clamps shall be of suitable design
according to the nature of construction of
ceiling on which these clamps are to be fitted.
In all cases fan clamps shall be fabricated from
new metal of suitable sizes and they shall be
58
NATIONAL BUILDING CODE OF INDIA 2016
as close fitting as possible. Fan clamps for
reinforced concrete roofs shall be buried with
the casting and due care shall be taken that
they shall serve the purpose. Fan clamps for
wooden beams, shall be of suitable flat iron
fixed on two sides of the beam and according
to the size and section ot the beam one or two
mild steel bolts passing through the beam shall
hold both flat irons together. Fan clamps for
steel joist shall be fabricated from flat iron to
fit rigidly to the bottom flange of the beam.
Care shall be taken during fabrication that the
metal does not crack while hammer to shape.
Other fan clamps shall be made to suit the
position, but in all cases care shall be taken to
see that they are rigid and safe.
d) Canopies on top and bottom of suspension
rods shall effectively conceal suspensions and
connections to fan motors, respectively.
e) The lead-in-wire shall be of nominal cross-
sectional area not less than 1.5 mm2 copper
and shall be protected from abrasion.
f) Unless otherwise specified, the clearance
between the bottom most point of the ceiling
fan and the floor shall be not less than 2.4 m.
The minimum clearance between the ceiling
and the plane of the blades shall be not less
than 300 mm.
A typical arrangement of a fan clamp is given in Fig. 4.
NOTE — All fan clamps shall be so fabricated that fans revolve
steadily.
7.8.2 Exhaust Fans
For fixing of an exhaust fan, a circular hole shall be
provided in the wall to suit the size of the frame which
shall be fixed by means of rag-bolts embedded in the
wall. The hole shall be nearly plastered with cement
and brought to the original finish of the wall. The
exhaust fan shall be connected to exhaust fan point
which shall be wired as near to the hole as possible by
means of a flexible cord, care being taken that the blades
rotate in the proper direction.
7.8.3 Fannage
7.8.3. 1 Where ceiling fans are provided, the bay sizes
of a building, which control fan point locations, play
an important part. Fans of 1 200/1 400 mm sweep
normally cover an area of 9 m2 to 10 m2 and therefore
in general purpose office buildings, for every part of a
bay to be served by the ceiling fans, it is necessary that
the bays shall be so designed that full number of fans
can be suitably located for the bay, otherwise it will
result in ill-ventilated pockets. In general, fans in long
halls may be spaced at 3 m in both the directions. If
building modules do not lend themselves for proper
positioning of the required number of ceiling fans, other
fans such as, air circulators or bracket fans will have to
be employed for the areas uncovered by the ceiling fans.
For this, suitable electrical outlets shall be provided
although result will be disproportionate to cost on
account of fans.
7. 8.3. 2 Proper air circulation may be achieved either
by larger number of smaller fans or smaller number of
larger fans. The economics of the system as a whole
should be a guiding factor in choosing the number and
type of fans and their locations. For design guidelines
in this regard, reference shall be made to Part 8
‘Building Sendees, Section 1 Lighting and Natural
Ventilation’ of the Code.
7. 8.3.3 Exhaust fans are necessary for spaces, such as
community toilets, kitchens and canteens, and godowns
to provide the required number of air changes ( see
Part 8 ‘Building Sendees, Section 3 Air Conditioning,
Pleating and Mechanical Ventilation’ of the Code).
Since the exhaust fans are located generally on the outer
walls of a room, appropriate openings in such walls
shall be provided for, in the planning stage.
NOTE — Exhaust fan requirement is based on the
recommended air changes (see Part 8 ‘Building Services,
Section 3 Air Conditioning, Heating and Mechanical
Ventilation’ of the Code). Reference shall also be made to Part
4 ‘Fire and Life Safety’ of the Code for exhaust fan requirements
for smoke extraction.
7.9 Attachment of Fittings and Accessories
7.9.1 In wiring other than conduit wiring, all ceiling
roses, brackets, pendants and accessories attached to
walls or ceilings shall be mounted on substantial teak
wood blocks twice varnished after all fixing holes are
made in them. Blocks shall not be less than 40 mm
deep. Brass screws shall only be used for attaching
fittings and accessories to their base blocks.
7.9.2 Where teak or hardwood boards are used for
mounting switches, regulators, etc, these boards shall
be well varnished with pure shellac on all four sides (both
inside and outside), irrespective of being painted to match
the surroundings. The size of such boards shall depend
on the number of accessories that can be conveniently
and neatly be arranged. Where there is danger of attack
by white ants, the boards shall be treated with suitable
anti-tennite compound and painted on both sides.
7.10 Interchangeability
Similar parts of all switches, lamp holders, distribution
fuse-boards, ceiling roses, brackets, pendants, fans and
all other fittings shall be so chosen that they are of the
same type and interchangeable in each installation.
7.11 Equipment
Electrical equipment which form integral part of wiring
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
59
4B SLAB WITH BEAM
All dimensions in millimetres.
NOTES
1 RCC slab steel reinforcement not shown.
2 Fan clamp shall be placed in position such that its projecting arms are in the line of length of beam.
Fig. 4 Typical Design of Fan Clamps
60
NATIONAL BUILDING CODE OF INDIA 2016
intended for switching or control or protection of wiring
installations shall conform to the relevant Indian
Standards, wherever they exist.
7.12 Positioning of fans and light fittings shall be
chosen to make these effective without causing shadows
and stroboscopic effect on the working planes.
8 EARTHING
8.1 General
8.1.1 Earthing is an essential part of any electrical
installation, essential for the safety from electrical
shock, and fire and for operation of most of the
protective systems of the electrical installation. The
earthing provides the necessary reference of zero
potential and helps in activating the operation of the
circuit breaker provided for the safe disconnection of
power in the event of an abnormality in the flow of
current. Earthing systems, apart from addressing safety
from shock and fire, help in limiting the interference
between one appliance and the other. This is of
particular importance in the case of voice and data
communication devices. With the proliferation in
electrical/electronic gadgets and greater dependence
on voice and data communication systems, proper and
effective earthing or grounding is very important.
Earthing is also necessary for diverting the effects of
lightning strikes from the buildings and its contents,
including from sensitive equipment.
8.1.2 Different types of earth electrodes and different
types of earthing systems available. For low voltage and
medium voltage systems which apply to almost all
electrical systems of buildings, the common earthing
system followed is with the neutral solidly earthed at the
source. This system requires that there is always a
protective earth continuity conductor running all through
the system and all metal parts of electrical appliances
connected to an electrical system are connected to the
earth continuity conductor. The exception to this system
is the double insulated appliances which are connected
to the line and neutral and operate on low voltage (single
phase) and are also of low power consumption. All
appliances (other than double insulated devices) use the
earthing through the earth continuity conductor. Single
phase appliances use a 3-wire connection with line (live
wire), neutral (return path wire) and the earth-wire at
zero potential. Three phase appliances use a connection
with 4-wires for a load which does not require a neutral
connection or use a 5-wire connection if the appliance
requires a neutral connection. Care should be taken to
ensure that the earthing system, the earth continuity
conductor and in case of sockets plugs the earthing pin
are not disconnected.
8.1.3 Different earthing systems have features which
are suitable for different applications. Earthing system
adopted, should be so selected so as to match with the
type of load, protection device, application, degree of
reliability, etc. For classification of electrical systems
based on the relationship of the source, and of exposed-
conductive parts of the installation, to earth, seelA.15.
8.2 Selection and Design of Earthing System
8.2.1 Earthing shall generally be carried out in
accordance with the requirements of Regulation 1 6, 41
and 48 of Central Electricity Authority (Measures
relating to Safety- and Electricity > Supply) Regulations ,
20 1 0 as amended from time-to-time (see Annex B) and
good practice [8-2(44)] and the relevant regulations of
the Electricity Supply Authority concerned.
8.2.2 Conductors and earth electrodes in an earthing
system shall be so designed and constructed that in
normal use their performance is reliable and without
danger to persons and surrounding equipment. Earthing
system shall be designed such as to have touch potential
and step potential as specified in good practice
[8-2(44)]. The choice of a material depends on its ability
to match the particular application requirement. The
requirements for earthing arrangements are intended
to provide a connection to earth which,
a) is reliable and suitable for the protective
requirements of the installation;
b) can carry earth fault currents and protective
conductor currents to earth without danger
from thermal, thermo-mechanical and
electromechanical stresses and from electric
shock arising from these currents;
c) if relevant, is also suitable for functional
requirements; and
d) is suitable for the foreseeable external
influences {see good practice [8-2(44)] and
IEC 60364-5-51 :2005 ‘Electrical installations
of buildings — Part 5-51: Selection and
erection of electrical equipment — Common
rules’}, for example, mechanical stresses and
corrosion.
8.2.3 The main earthing system of an electrical
installation shall consist of,
a) an earth electrode, (electrode can be one
vertical rod/pipe/buried plate or an earth mat
with several vertical installations or a ring
earthing with vertical installations.
b) a main earthing wire;
c) an earth bar (located on the main switchboard
for small installation and installed in the wall/
room in case of large industrial electronic
installations) for the connection of the main
earthing wire, protective earthing wires and/
or bonding wires within the installation; and
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
61
d) a removable link, which effectively
disconnects the neutral bar from the earth bar.
NOTE — The requirements of (c) and (d) shall be carried out
by a licensed electrician as part of the switchboard installation.
8.2.4 The main earthing wire connection shall,
a) be mechanically and electrically sound;
b) be protected against damage, corrosion, and
vibration;
c) not place any strain on various parts of the
connection;
d) not damage the wire or fittings; and
e) be secured at the earth electrode.
8.2.4.1 The main earthing wire termination shall be
readily accessible at the earth electrode except
for 8.2.20. As far as possible, all earth connections,
except exothermically welded, shall be visible for
inspection.
8.2.5 Consideration shall be given to the earthing
arrangements where currents with high frequencies are
expected to flow {see 444 of IEC 60364-4-44:2007
‘Low-voltage electrical installations — Part 4-44:
Protection for safety — Protection against voltage
disturbances and electromagnetic disturbances’).
8.2.6 Protection against electric shock ( see IEC 60364-
4-41 ‘Low-voltage electrical installations — Part 4-
41 : Protection for safety — Protection against electric
shock’), shall not be adversely affected by any
foreseeable change of the earth electrode resistance (for
example, due to corrosion, drying or freezing).
8.2.7 Where the supply to an installation is at high or
extra high voltage, requirements concerning the
earthing arrangements of the high or extra high voltage
supply and of the low-voltage installation shall also
comply with 442 of IEC 60364-4-44:2007 ‘Low-
voltage electrical installations — Part 4-44: Protection
for safety — Protection against voltage disturbances
and electromagnetic disturbances’.
8.2.8 A permanent fitting (like a screwed-down plastic
label or copper label, or one that can be threaded onto
the cable) shall be used at the connection point that is
clearly marked with the words: ‘EARTHING LEAD
— DO NOT DISCONNECT’ or ‘EARTHING
CONDUCTOR — DO NOT DISCONNECT’.
8.2.9 All medium voltage equipment shall be earthed
by two separate and distinct connections with earth.
The contact area of earth conductor/plate shall be
determined in accordance with good practice
[8-2(44)].
8.2.9. 1 The 415/240 V, 4-wire, 3 -phase systems are
normally operated with the neutral solidly earthed at
source. At medium voltage, Central Electricity
Authority regulations require that the neutral be earthed
by two separate and distinct connections with earth.
Source in the case of a substation (such as 1 1 kV/4 1 5 V)
will be the neutral(s) of the transformer(s). Neutral
conductor shall be of the same size as the phase
conductor.
NOTE — Neutral conductor of half the size of the phase
conductor was permitted in earlier installations. But with the
proliferation of equipment using non-linear devices and
consequent increase in harmonics, the neutral will carry a
current more than the notional out-of-balance current and
therefore neutral conductor shall be of the same size as the
phase conductor.
8.2.10 In the case of high and extra high voltages, the
neutral points shall be earthed by not less than two
separate and distinct connections to earth, each having
its own electrode at the generating station or substation
and may be earthed at any other point provided no
interference is caused by such earthing. The neutral
may be earthed through suitable impedance. Neutral
earthing conductor shall be sized as to have a current
carrying capacity not less than the phase current.
8.2.11 For industrial/commercial installations having
a transformer within the facility, soil resistivity of the
place of installation shall be measured as per good
practice [8-2(44)] and recorded. For the adopted type
of earth electrode configuration, earth resistance of each
electrode configuration shall be calculated and recorded
based on good practice [8-2(44)].
8.2.12 It is recommended that a drawing showing the
main earth connection and earth electrodes be prepared
for each installation.
8.2.13 Conductors, other than live conductors, and any
other parts intended to carry a fault current shall be
capable of carrying that current without attaining an
excessive temperature.
8.2.14 Earth system shall be so devised that the testing
of individual earth electrode is possible {except for
installations according to 5.3.6 of good practice
[8-2(45)]} . It is recommended that the value of any earth
system resistance shall be such as to conform to the
degree of shock protection desired. For measuring
purposes, the joint shall be capable of being opened with
the aid of a tool. In normal use it shall remain closed.
8.2.15 No addition to the current-carrying system, either
temporary or permanent, shall be made which will
increase the maximum available earth fault current or
its duration until it has been ascertained that the existing
arrangement of earth electrodes, earth bus-bar, etc, are
capable of carrying the new value of earth fault current
which may be obtained by this addition.
8.2.16 No cut-out, link or switch other than a linked
switch arranged to operate simultaneously on the
62
NATIONAL BUILDING CODE OF INDIA 2016
earthed or eaithed neutral conductor and the live
conductors, shall be inserted on anv supply system.
This, however, does not include the case of a switch
for use in controlling a generator or a transformer or a
link for test purposes.
8.2.17 All materials, fittings, etc, used in earthing shall
conform to relevant Indian Standard specification,
wherever these exist.
8.2.18 Earthing associated with current-carrying
conductor is normally essential for the function of the
system and is generally known as system earthing or
functional earthing, while earthing of non-current
carrying metal work and conductor is essential for the
safety of human life, of animals and of property and it
is generally known as equipment earthing or protective
earthing. The earthing arrangements may be used jointly
or separately for protective and functional purposes
according to the requirements of the electrical
installation. The requirements for protective purposes
shall always take precedence.
8-2.19 For selection of electrodes for use in corrosive
environments, reference shall be made to good practice
[8-2(44)].
8.2.20 Test joints are not required in the case of natural
down-conductors combined with foundation earth
electrodes (see Fig. 5).
8.2.21 For computer and other sensitive electronic
equipment system in industrial and commercial
application, special bonding techniques with isolation
transformer should be employed (see Fig. 6).
8.2.22 Isolated earthing is unsafe during a transient
condition. In unavoidable conditions if isolated earthing
is used, to reduce potential difference between isolated
earthing, earth couplers or isolating spark gaps shall
be installed. This will reduce potential difference during
a transient condition such as lightning.
8.3 Earth Electrodes
The efficacy of any earth electrode depends on its
configuration and upon local soil conditions. Number
of earth electrodes suitable for the soil conditions and
the value of resistance to earth required shall be
considered. Examples of earth electrodes which may
be used are,
a) concrete-embedded foundation earth
electrode;
b) soil-embedded foundation earth electrode;
c) metallic electrode embedded directly in soil
vertically or horizontally (for example rods,
wires, tapes, pipes or plates);
d) metal sheath and other metal coverings of
cables according to local conditions or
requirements;
e) other suitable underground metalwork (for
example, pipes) according to local conditions
or requirements; and
f) welded metal reinforcement of concrete
(except pre-stressed concrete) embedded in
the earth.
The type, materials and dimensions of earth electrodes
shall be selected to withstand corrosion and to have
adequate mechanical strength for the intended lifetime.
For materials commonly used for earth electrodes, the
minimum sizes, from the point of view of corrosion
and mechanical strength, when embedded in the soil
or in concrete, may be as specified in Table 3. If a
lightning protection system is required, 11.5.3 applies
{see 5.4 of good practice [8-2(45)]}.
NOTES'
1 For corrosion, the parameters to be considered are: the soil
pH at the site, soil resistivity, soil moisture, stray and leakage
a.c. and d.c. current, chemical contamination, and proximity
of dissimilar materials.
2 The minimum thickness of protective coating is greater for
vertical earth electrodes than for horizontal earth electrodes
because of their greater exposure to mechanical stresses while
being embedded.
Earth electrode either in the form of solid rod, pipe,
plate or earth grid should be provided at all premises
for providing an earth system. Details of typical pipe,
rod and plate earth electrodes are given in Fig. 7 and
Fig. 8. Other electrode configurations can be as in Fig. 9
{see also 9.2 of good practice [8-2(44)]}.
Although electrode material does not affect initial earth
resistance, care should be taken to select a material
which is resistant to corrosion in the type of soil in
which it is used. In case where soil condition leads to
excessive corrosion of the electrode, and the
connections, it is recommended to use either copper/
stainless steel or copper coated steel electrode and
copper/stainless steel connections. Exothermic welding
may also be adopted to have enhanced life and strength
to the connection (see Fig. 7B and Fig. 8B). It is
recommended to use similar material for earth
electrodes and earth conductors or otherwise
precautions should be taken to avoid corrosion.
8.4 Earth Enhancing Compound
Multiple rods, even in large numbers, may sometime
fail to produce an adequately low resistance to earth.
This condition arises in installations involving soils of
high resistivity. The alternative is to reduce the
resistivity of the soil immediately surrounding the earth
electrode. To reduce the soil resistivity, artificial soil
treatment shall be adopted.
8.4.1 Earthing enhancing compound is a conductive
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
63
NOTES
1 Functional earthing conductors are not shown in figure.
2 Where a lightning protection system is installed, the additional requirements
are given in 11.
Key
C
Extraneous-conductive-part
Cl
Water pipe, metal from outside
C2
Waste water pipe, metal from outside
C3
Gas pipe with insulating insert, metal
from outside
C4
Air conditioning
C5
Heating system
C6
Water pipe, metal for example in a
bathroom
C7
Waste water pipe, metal for example
in a bathroom
D
Insulating insert
MDB
Main distribution board
DB
Distribution board
MET
Main earthing terminal
SEBT
Supplementary equipotential bonding
terminal
T1
Concrete-embedded foundation earth
electrode or soil-embedded foundation
earth electrode
T2
Earth electrode for LPS, if necessary
LPS
Lightning protection system (if any)
PE
PE terminal(s) in the distribution board
PE/PEN
PE/PEN terminal(s) in the main
distribution board
M
Exposed-conductive-part
1
Protective earthing conductor (PE)
1A
Protective conductor, or PEN conductor,
if any, from supplying network
2
Protective bonding conductor for
connection to the main earthing terminal
3
Protective bonding conductor for
supplementary bonding
4
Down conductor of a lightning protection
system (LPS), if any
5
Earthing conductor
Fig. 5 Example of an Earthing Arrangement for Foundation Earth Electrode, Protective
Conductors and Protective Bonding Conductors
64
NATIONAL BUILDING CODE OF INDIA 2016
MAINS SUPPLY
3 PHASE 415 V
LU C4 >- CD
<3 s Q
Key
1 —
L
n
Isolation transformer
Core
Shield
All earthing connections made at a point
Connection to building steel/earth
pits/ring earthing
6 Conduit earthing
7 Neutral
8 240/415 Volt power panel
9 Neutral bus1)
10 Earth bus1)
1 1 Earth connection for socket/work
station/computers
12 3-pin sockets with isolated earth pin
11 Both busbars isolated from panel
enclosure. No bonding connection
between neutral and earth.
NOTES
1 Each branch circuit shall have a separate neutral
and earth wire. No daisy chaining permitted.
2 Only computer or control system should be served
from this panel.
■11
Fig. 6 Recommended Power Distribution for a Computer and Control System with
a Delta/Star Isolation Transformer
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
65
Table 3 Recommended Minimum Size of Commonly Used EarthEleetrodes, Embedded in Soil or
Concrete Used to Prevent Corrosion and Provide Mechanical Strength])
( Clause 8.3)
SI
Material and
Shape
Diameter
Cross-
Thickness
Weight of
Thickness of
No.
Surface
Sectional
Coating
Coating/
Area
g/m2
Sheathing
mm
mm2
mm
jim
0)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
i)
Steel embedded in
Round wire
10
_
_
concrete (bare, hot
galvanized or
Solid tape or strip
—
75
—
—
it)
stainless)
Steel hot-dip
Strip3* or shaped
90
3
500
63
galvanized2*
strip/plate — solid
plate — lattice plate
Round rod installed
16
350
45
vertically
Round wore installed
10
350
45
horizontally
Pipe
25
2
350
45
Stranded
—
70
—
_
_ _
(embedded in
concrete)
Cross profile
installed vertically
—
(290)
3
—
—
in)
Steel copper sheathed
Round rod installed
vertically
05)
—
—
—
2 000
iv)
Steel with electro-
Round rod installed
14
—
_
_ _
250 6*
deposited copper
vertically
coating
Round wire installed
(8)
—
—
_
70
horizontally
Strip installed
horizontally
—
90
' >
J
—
70
v)
Stainless steel 4*
Strip3* or shaped
strip/plate
—
90
3
—
—
Round rod installed
vertically
16
—
—
—
—
Round wire installed
10
—
_
_
horizontally
Pipe
25
2
vi)
Copper
Strip
50
2
_
Round wire installed
horizontally
—
(25)5> 50
—
—
—
Round rod installed
vertically
(12) 15
—
—
—
—
Stranded wire
1.7 for
individual
(25)5* 50
—
—
—
strands of wire
Pipe6*
20
—
2
_
Solid plate
—
—
(1.5)2
_
_
Lattice plate
—
—
2
—
_
11 See IEC 60364-5-54:201 1 ‘Low-voltage electrical installations - Part 5-54: Selection and erection of electrical equipment - Earthing
arrangements and protective conductors’. /
2> The coating shall be smooth, continuous and free. from flux stains.
3) As rolled strip or slit strip with round edges.
4> Chromium > 16 percent, Nickel > 5 percent, Molybdenum > 2 percent, carbon < 0.08 percent.
;,) Where experience shows that the risk of corrosion and mechanical damage is extremely low, 16 mm2 can be used.
61 rhls thickness is provided to withstand mechanical damage of copper coating during the installation process. It may be reduced to not
less than 100 pm where special precautions to avoid mechanical damage of copper during the installation process (for example, drilling
holes or special protective tips) are taken according to the manufacturer’s instruction.
NOTES
1 Values in bracket are applicable for protection against electric shock only, while values not in brackets are applicable for lightning
protection and for protection against electric shock.
2 Metals inserted inside pipe will not influence in the final earth resistance value.
3 Unprotected ferrous materials are not recommended due to high corrosion (see IEC 60364-4-43:2008 ‘Low-voltage electrical
installations Part 4-43: Protection for safety - Protection against overcurrent’).
66
NATIONAL BUILDING CODE OF INDIA 2016
compound producing low resistance of an earth-
termination system. These compounds used for artificial
treatment of soil {see good practice [8-2 (44)] j shall
satisfy the requirements as per IEC 62561-7:2011
‘Lightning protection system components (LPSC) _
Part 7. Requirements for earthing enhancing
compounds’.
8.4.2 The material of the earthing enhancing compound
shall be chemically inert to subsoil. It shall not pollute
the environment. It shall provide a stable environment
in terms of physical and chemical properties and exhibit
low resistivity. The earthing enhancing compound shall
not be corrosive to the earth electrodes being used.
8.4.3 The materials used for artificial treatment should
also fulfil toxicity characteristic leachine
procedure (TCLP) requirements.
8.4.4 Use of salt [sodium chloride (NaCl)] for artificial
treatment of soil should be avoided as it accelerates
corrosion of ferrous materials.
8.5 Earth Electrode Inspection Housings and Earth
Electrode Seals
8.5.1 Earth Electrode Inspection Housing
Earth electrode inspection housing is the metallic or
non-metallic enclosure that houses the down-conductor/
earth-termination connection for inspection and testing
purposes and consists of a housing and a removable
lid. The design of the earth electrode inspection housing
shall be such that it carries out its function of enclosing
the down-conductor/earth rod termination in an
acceptable and safe manner, and has sufficient internal
dimensions to permit the assembly/disassembly of the
earth rod clamp. The housing body shall be deep enough
to permit the lid to sit flush on the body without fouling
on the rod/conductor/clamp assembly. The material of
the earth electrode inspection housing shall be
compatible with its surrounding environment and shall
comply with the tests given in IEC 62561-5: 2011
‘Lightning protection system components (LPSC) —
Part 5: Requirements for earth electrode inspection
housings and earth electrode seals’.
8.5.2 Earth Electrode Seal
Water pressure seal used in conjunction with an earth
rod electrode that passes through the foundation of the
building. The design of the earth electrode seal shall
be such that it carries out its function of preventing
ground water bypassing the earth rod and entering the
basement of a building, in an acceptable and safe
manner. The material of the earth electrode seal shall
be compatible with its surrounding environment and
comply with the tests given in IEC 62561-5: 2011
‘Lightning protection system components (LPSC) —
Part 5: Requirements for earth electrode inspection
housings and earth electrode seals’.
8.6 Bonding and Inter connection
All connections made in an earthing system above or
below ground should meet electrical conductivity,
corrosion resistance, current carrying capacity, and
mechanical strength of the conductor. These
connections should be strong enough to maintain a
temperature rise below that of the conductor and to
withstand the eflect of heating and the mechanical
forces caused by fault currents. Consideration shall be
given to electrolytic corrosion when using different
materials in an earthing arrangement. The complete
connections shall be able to resist corrosion for the
intended life of the installation
8.6.1 For external conductors (for example earthing
conductor) connected to a concrete-embedded
foundation earth electrode, the connection made from
hot-dip galvanized steel shall not be embedded in the
soil
8.6.2 Where an earth electrode consists of parts that
must be connected together, the connection shall be by
exothermic welding, pressure connectors, clamps or
other suitable mechanical connectors.
8.6.3 All connection components shall meet the
requirements according to IEC 62561-1:2012
‘Lightning protection system components (LPSC) —
Part 1 : Requirements for connection components’.
8.7 Equipment and Portions of Installations which
shall be Earthed
8.7.1 Equipment to be Earthed
Except for equipment provided with double insulation,
all the non-current carrying metal parts of electrical
installations are to be earthed properly. All metal
conduits, trunking, cable sheaths, switchgear,
distribution fuse boards, lighting fittings and all other
parts made of metal shall be bonded together and
connected by means of two separate and distinct
conductors to an efficient earth electrode.
8.7.2 Structural Metal Work
Earthing of metallic parts of the structure shall be done
according to good practices [8-2(44)] and [8-2(45)]:
8.8 Neutral Earthing
To comply with relevant Central Electricity Authority
regulations, no fuses or circuit breakers other than a
linked circuit breaker shall inserted in an earthed neutral
conductor, a linked switch or linked circuit breaker shall
be arranged to break or the neutral either with or after
breaking all the related phase conductors and. Shall
positively make (or close) the neutral before making
(or closing) the phases.
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
67
Key
1 a) Cl pipe 100 mm ID (Min), 13 mm thick (Min)
b) Gl pipe (class B)/MS Rod, 40 mm ID (Min)
2 Earth enhancement material [confirming to IEC 62561-7:2011 'Lightning protection system components (LPSC) —
Part 7: Requirements for earthing enhancing compounds’],
or sand, salt and charcoal
3 Inspection chamber
4 Universal stainless steel clamp,
or 50 x 3 mm Gl strip
5 M10 bolts and nuts
6 Funnel (for maintenance/watering)
7 Cl lid/cover
8 50 x 6 mm Gl strip
All dimensions in millimetres.
NOTE — Inspection housing can also be of FRP materials with Cl cover tested according to IEC 62561-5:201 1 ‘Lightning protection
system components (LPSC) — Part 5: Requirements for earth electrode inspection housings and earth electrode seals’.
7 A TYPICAL ARRANGEMENT OF EARTHING WITH PIPE ELECTRODE
(WITH MAINTENANCE ARRANGEMENT)
Fig. 7 — ( Continued)
68
NATIONAL BUILDING CODE OF INDIA 2016
09Z L - -H* - - - 000 £•
Key
1 Copper/copper bonded steel rod (see Table 3 for sizes)
2 Earth enhancement material [conforming to IEC 62561-7:2011 ‘Lightning protection system components (LPSC) _
Part 7: Requirements for earthing enhancing compounds’]
3 Inspection chamber
4 Ml 0 bolts and nuts
5 Copper strip — 25 x 6 mm or higher
6 Exothermic welding
7 Cl lid/cover
All dimensions in millimetres.
NOTE Inspection housing can also be of FRP materials with Cl cover tested according to IEC 62561 -5:2011 ‘Lightning protection
system components (LPSC) — Part 5: Requirements for earth electrode inspection housings and earth electrode seals’.
7B TYPICAL ARRANGEMENT OF EARTHING WITH COPPER/COPPER BONDED ELECTRODE WITH
EXOTHERMIC WELDING (MAINTENANCE FREE ARRANGEMENT)
Fig. 7 Typical Arrangement of Electrode Earthing
PART 8 BUILDING SERVICES — SECTION 2 ELECTRICAL AND ALLIED INSTALLATIONS
1 250
Key
1 50 mm dia Gl pipe for watering (maintenance)
2 a) 35 x 6 mm copper strip
b) 50 x 12 mm Gl Strip
3 Inspection chamber
4 Funnel (for watering/maintenance)
5 Earth enhancement material [conforming to IEC 62561-7:2011 ‘Lightning protection system components (LPSC) —
Part 7: Requirements for earthing enhancing compounds’],
or sand, salt and charcoal
6 a) 600 x 600 x 3 mm copper plate
b) 600 x 600 x 6 mm Gl plate
c) 1 200 x 1 200 x 12 mm Cl plate
7 a) M12 x 40 brass bolts and nuts
b) M12 x 60 Gl bolts and nuts
8 a) Ml 0 x 30 brass bolts and nuts
b) M12 x 50 Gl bolts and nuts
9 a) Ml 2 x 40 brass bolts and nuts
b) M12 x 60 Gl bolts and nuts
10 a) 35 x 6 copper strip
b) 50 x 12 mm Gl strip
11 Cl lid/cover
12 a) 25 x 4 mm copper strip for clamp
b) 50 x 12 mm Gl copper strip for clamp
All dimensions in millimetres.
NOTE — Inspection housing can also be of FRP materials with Cl cover, tested according to IEC 62561-5: 2011 ‘Lightning
protection system components (LPSC) — Part 5: Requirements for earth electrode inspection housings and earth electrode seals’.
8A TYPICAL ARRANGEMENT OF CI/GI/COPPER PLATE EARTHING (WITH MAINTENANCE ARRANGEMENT)
Fig. 8 — ( Continued )
70
NATIONAL BUILDING CODE OF INDIA 2016
8
DETAIL A
Key
1
2
3
4
5
6
7
8
600 x 600 x 3 mm copper plate
30 x 6 mm copper strip
Exothermic welding
Earth enhancement material fconformina to IEC 62661 7-2nn 'i *
Part 7: Requirements for earthing enhancing co 
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