National Building Code of India (NBC) guidelines

The National Building Code (NBC) is a standardised codes document that provides guidelines for construction of structures. These norms are meant to protect the overall health of the construction and ensure the health and safety of the public and the residents. It is mandatory to adhere to NBC standards for hostels, NBC norms for high rise building, NBC standards for residential buildings, mercantile, institutional, educational, commercial, assembly, storage spaces or even hazardous buildings. In this article, we are going to talk about the NBC guidelines for residential buildings. The NBC guidelines were first published in 1970 and revised in 1983 and subsequently in 2005.

Table of Contents

What is the importance of NBC in construction and development?

These are a set of rules that is used for controlling construction activities so that the safety of the occupants in the building is taken care of. The NBC is a combination of municipal rules and construction rules based on which the building structures are planned and built. The NBC emphasises on integrity and quality of finished product.

What are residential buildings as per NBC guidelines?

As per the National Building Code of India (NBC guidelines), residential buildings include any building that is equipped with sleeping accommodation for normal residential purposes, with or without cooking and dining facilities, except any building classified under Group C.

What are the types of residential buildings as per NBC?

Residential buildings are classified into the following categories:

Lodging or rooming houses.
One or two-family private dwellings.
Dormitories.
Apartment houses or flats.
Hotels.
Group housing: This includes multiple buildings in a same complex, gated communities etc.
Multi-family housing: This will include multiple things in the same complex.
Row houses: These are independent houses that share a common wall.
Detached buildings: These are stand alone buildings that can be a single building or a bungalow or a villa etc.
Semi-detached buildings: These are apartments like duplexes.

Importance of NBC in real estate

As the NBC provides a set of rules, construction of property across the country follows a standard process. This will also ensure quality construction of the project.

Compliance

It is important that all construction that takes place are compliant to NBC guidelines. There are strict guidelines related to safety of the residents that includes fire safety, sanitation and structural quality. These have to be followed compulsorily to avoid accidents.

All materials used for construction purposes should be of high quality and should comply with the Bureau of Indian Standard specifications. No building or a part of the building should be constructed, destroyed or constructed again in between a building and an overhead electric supply line.

Environmental sustainability

The NBC guidelines also focus on the environmental standards thus promoting green building. This also keeps in check the problems that can be caused in the environment by excessive construction.

Zoning and use of land under NBC guidelines

Under the NBC, land is divided into various zones, such as residential, commercial, industrial, recreational, and mixed-use zones. There are specific guidelines that have to be followed for each zone and this includes activities that are permitted, the height restriction, points with respect to parking etc.

National Building Code: Building height based classification

According to the National Building Code, buildings are divided on the basis of their height- low-rise, mid-rise and high-rise categories and accordingly the safety, structural and fire prevention standards are decided.

Up to 4 stories are low-rise buildings in which according to NBC guidelines basic fire safety and accessibility features should be available.
Between 5 to 10 stories are mid-rise buildings that should have improved fire safety measures such as fire alarms, extinguishers and many different evacuation routes.
More than 10 stories have to follow strict NBC guidelines with respect to fire safety, evacuation protocols and structural integrity.

NBC codes for kitchens

Every kitchen must have provision for washing utensils, with proper connection to drainage.
The kitchen must be provided with an impermeable floor.
The kitchen must open into an interior or exterior open space and should not be less than one sq metre.
The kitchen should not open into a shaft.
No chutes to be used in buildings above 15 metres.

See also: DTPC full form & DTPC approval

NBC guidelines for bathrooms

One of the walls should have an opening to the open air. Minimum ventilation or window space should be provided measuring up to 0.37 sq metre.
A bathroom must always be over another bathroom or washing place or the terrace space and not over another room. Watertight floors can be an exception to this rule.
The seat should be made of non-absorbent material.
Bathrooms should be enclosed by partitions/walls, provided with an impervious surface with a height prescribed as not less than one metre.
The floor covering should be impervious too but sloping towards the drain and not towards any other room or balcony space.
A room provided with a water closet is to be used as a toilet only. These rooms must be provided with flush cisterns.
If there is a toilet on the terrace with a height of 2.2 metre, it should be counted in the Floor Area Ratio (FAR).
In the absence of a sewage outlet, a septic tank must be provided.

NBC guidelines for lofts

Apart from shops, lofts are permitted in residential buildings only.
The area of the loft should be restricted to 25% of the covered area.
The height between the loft and ceiling should not be less than 1.75 metre.

NBC guidelines for basements

The minimum height of the basement should be 2.5 metre and the maximum height 4.5 metre.
The ceiling height should be a minimum of 0.9 metre and maximum of 1.2 metre above the road surface.
Ventilation is must for the basement and could be in the form of blowers, exhaust fans, air-conditioning, etc.
Surface drainage should not enter the basement.
The basement’s walls and floors must be water-proof.
The basement should not be accessed directly from the road. It should be accessed only from the main entrance or an alternative staircase that provides access to the building.
Only when a projecting basement is flush with the ground, or if the authority allows, can the basement be permitted to touch the adjacent property.

NBC guidelines for garages

The plinth of the garage at ground level should not be less than 15 cm.
Garages should not block access to the building in any way. It should be behind the building line of the street or road. In case it is not, the authority may even discontinue its use as a garage or suggest other alterations.

Staircase width as per NBC guidelines

For group housing, where the floor area does not exceed 300 sqm and the height of the building is not over 24 metre, a single staircase may be acceptable. In buildings that are identified in Bye-Laws No 1.13 VI (a) to (m), a minimum of two staircases are compulsory.
In a residential low-rise building, the minimum staircase width as per NBC is 0.9 metre.
For flats, hostels, group housing, guest houses, staircase width as per NBC is 1.25 metre.

Guidelines for stairways in residential structures

The interior stairs must be constructed of non-combustible material only.
It must have one side adjacent to an external wall and should be completely enclosed.
It is the chief fire officer who needs to approve of the staircase’s location.
The minimum height of handrails should be 100 cm.
The minimum width of treads, staircase, its arrangement, headroom, needs to follow the standards as prescribed by the NBC.
Living spaces and stores cannot open up into the staircase.
The main staircase and fire escape staircase must be continuous from ground floor to the terrace level.
No electrical shafts or AC ducts and gas pipelines can run through the staircase.
Nothing that is combustible can be used for decoration or panelling of the staircase.
Beams and columns should not reduce the headroom or width of the staircase.

NBC for residential building open areas

Every room, habited by people, should open into an exterior or interior open space or verandah.
Open spaces should be counted in the FAR, as per the master plan.
These areas should be free of erections of any kind, except cornice, chajja or weather shade that is not more than 0.75 metres wide.
Every interior or exterior or air space should be maintained for the benefit of such building exclusively and shall be entirely within the owner’s own premises.

NBC codes related to building sites

In case of damp sites, the surface of the ground and space between the walls has to be declared damp-proof, to the satisfaction of the authority.
Building sites should be away from electric lines.

Type of electric line	Vertical distance	Horizontal distance
Low and medium voltage lines and service lines	2.50 metre	1.20 metre
High voltage lines up to and including 11,000 volts	3.70 metre	1.20 metre
High voltage lines above 11,000 volts and up to and including 33,000 volts	3.70 metre	2.00 metre
Extra high voltage lines additional 33,000 volts	Plus 0.3 metre for every additional 33,000 V or part thereof.	Plus 0.3 metre for every additional 33,000 V or part thereof.

The Master Plan and land development rules and regulations of the authority decide the minimum size of the site.

Also read about HOBPAS login: Everything about Haryana Online Building Plan Approval System

NBC Guidelines related to building exits

The NBC has guidelines for the entry, as well as exit points in buildings.

An exit must be provided in every building, so as to permit safe escape of residents in times of fire or earthquakes, etc.
Exits are compulsory and these should be clearly visible to all and must be illuminated. These cannot be reduced in number, width or by any other means. The requisite number is dependent on occupancy load, capacity, travel distance, etc.
Alarms are necessary to ensure those in danger are evacuated promptly.
Exits should be continuous, leading to the exterior of the building.
Exits can be horizontal or vertical.
Lifts and revolving doors are not exits.

NMC Fire safety: What are the norms for high-rise buildings?

In large-sized buildings where accidents due to fire may not be easily noticed, automatic fire detection and alarm facilities are a must and should be provided. Not just this, as per the National Building Code (NBC), high-rise buildings should have smoke detectors, sprinklers, first aid fire fighting system, PA system, adequate water supply, fire pumps, fire escape routes, fireman lift, service shaft enclosures, compact mentation, approved electrical system, refuse area etc. mentions the official fire safety rules portal of the Assam government.

Capacity of exits in different types of buildings

Group	Group of occupancy	Number of occupants
Group	Group of occupancy	Stairways	Ramps	Doors
A	Residential	25	50	75
B	Educational	25	50	75
C	Institutional	25	50	75
D	Assembly	40	50	60
E	Business	50	60	75
F	Mercantile	50	60	75
G	Industrial	50	60	75
H	Storage	50	60	75
I	Hazardous	25	30	40

Source: NBC, occupants per unit exit width

NBC norms for plumbing and sanitary systems

A plumbing or a sanitation code has to be followed by anyone maintaining the tanks that provide drinking water and service water to sewage or restrooms. This has to be done with high precision to avoid spread of illness.

When the plumbing system is being installed in the building, its architecture and design should be considered. Technical factors like water pressure, ventilation, and wet and dry toilet sections should be taken into consideration while preparing the design.

In India, Uniform Plumbing Code was recently introduced by the Indian Plumbing Association. This is the code developed by the World Plumbing Council and was modified to suit India requirements.

NBC guidelines: Occupancy and maintenance

As a proof that the project is complaint with the NBC guidelines, all projects should have an occupancy certificate (OC). Without this you cannot occupy the property nor sell it as these actually prove that the property is fit for human occupancy. In case there is OC, then the project is illegal and may also have risk of getting demolished.

Amendments to NBC guidelines

The NBC has introduced norms to strengthened guidelines promoting sustainability and green building practices.
Focus is on smart buildings with modern technology included like automated systems.
More care and rules and regulations drafted towards fire safety and disaster resilience for tower buildings.
Senior citizen and differently-abled access has been given priority.
Revision in classification of buildings based on height, use and occupancy.

In case of any future development, amendments made to the NBC has to ensure that the environment that is being developed is safe, secure, and sustainable. With advancements in technology and challenges like climatic conditions, ever developing social conditions etc. the NBC also has to evolve to imbibe what is best for the environment and safe for the people. To combat climate change, revision in designs such as flood-resistant structures will help. Reports suggest that for instance, when it comes to integrating smart building systems and renewable energy sources, NBC code updated with respect to electrical and energy efficient standards will help.

Housing.com POV

Real estate is growing as a result of increased population in the country. Along with Tier-1, Tier-2 and Tier-3 cities are getting prominence in the Indian real estate market map. With such speed in hand, adhering to NBC guidelines is essential now as this while providing an inclusive environment also is helping in meeting safety and sustainable standards.

FAQs

What is the building Code of India NBC?

Created by the BIS, the National Building Code of India 2016 is a national instrument that provides guidelines for construction of buildings in India.

What are the types of buildings as per NBC?

Residential, educational, institutional, assembly buildings, industrial buildings, storage buildings etc. are some of the types of buildings as per NBC.

Is National building Code of India mandatory?

While initially it was a voluntary code to be followed, after it was incorporated as part of the local bye-laws, it is mandatory to follow.

What are the objectives of the National building Code?

The NCB makes sure that the building that is constructed meets structural and safety conditions.

Who formulated NBC of India?

The National Building Code of India (NBC of India) is formulated and published by the Bureau of Indian Standards (BIS). It provides guidelines for construction activities, maintenance and fire safety of buildings.

Are lightning conductors good and useful as per National Building Code?

Yes, as per the NBC, the lightning rod protects buildings. Electrical and other equipment can be protected to a great degree, by installing lightning arrestors.

What is the minimum open area requirement in buildings that are 55 metres or more in height?

The minimum exterior open spaces around buildings that are 55 metres or more, should be 16 metres. On sides where no habitable rooms face, a minimum space of 9 metres shall be left for heights above 27 metres.

What does the National Building Code say about parapets?

Parapet walls and handrails provided on the edges of roof terrace, balcony, etc., should not be less than one metre and more than 1.5 metres in height, as per the NBC.

Got any questions or point of view on our article? We would love to hear from you. Write to our Editor-in-Chief Jhumur Ghosh at jhumur.ghosh1@housing.com

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National Building Code of India: NBC norms for high rise building and other residential buildings