08-GENERAL BUILDING NORMS
GENERAL BUILDING NORMS
(See Rule 72)
(i) Every doorway shall open into an enclosed stairway, a horizontal exit, on a corridor or passageway providing continuous and protected means of egress.
(ii) No exit doorway shall be less than 1 meter in width. Doorways shall be not less than 2 meter in height. Doorways for bathrooms, water closet and stores shall be not less than 0.75 meter wide.
(iii) Exit doorways shall open outwards, that is, away from the room but shall not obstruct the travel along any exit. No door, when opened, shall reduce the require width of stairway or landing to less than 0.9 meter, overhead or sliding doors shall not be installed.
(iv) Exit door shall not open immediately upon a flight or stairs, a landing equal to at least the width of the door shall be provided in the stairway at each doorway, level of landing shall be the same as that of the floor which it serves.
(v) Exit doorways shall be openable from the side which they serve without the use of a key.
(vi) Mirrors shall not be placed in exit ways or exit doors to avoid confusion regarding the direction of exit. (vii) Revolving doors shall not be provided as a means of fire exit
(i) A staircase shall not be arranged round a lift shaft
(ii) The staircase shall be ventilated to the atmosphere at each landing and a vent at the top; the vent openings shall be of 0.5 square meter in the external wall and the top. If the staircase cannot be ventilated, because of location or other reasons, a positive pressure 50 Pa shall be maintained inside. The mechanism for pressurizing the staircase shall operate automatically with the fire alarm. The roof of the shaft shall be 1 meter above the surrounding roof. Glazing or glass bricks if used in staircase, shall have fire resistance rating of minimum 2 hour.
'(iii) The minimum width of staircase shall be as in Table 1 herein contained—
|Table No. 1: Type of Building and Staircase Width
||Type of Building
||Residential buildings (dwellings)
||Residential Hotel Buildings
||Assembly buildings e.g. auditorium, theatres and cinemas
||Educational buildings up to 30 meter in height
||Institutional buildings like hospitals
||All other buildings
The minimum width of treads without nosing shall be 0.25 meter for staircase for residential buildings. In the case of other buildings the minimum tread shall be 0.3 meter. The treads shall be constructed and maintained in a manner to prevent slipping. The maximum height of riser shall be 0.19 meter in the case of residential buildings and 0.15 meter in the case of other buildings and shall be limited to 15 risers per flight.
(v) Handrails shall be provided with a minimum height of 0.9 meter from the center of the tread.
(vi) The minimum headroom in a passage under the lading of a staircase and under the staircase shall be 2.2 meter.
(vii) Access to main staircase shall be gained through adequate fire resistance rating (Table 1, Part IV of the National Building Code of India) Automatic closing doors placed in the enclosing walls of the staircases. It shall be a swing type door opening in the direction of the escape.
(viii) No living space, store or other fire risk shall open directly into the staircase or staircases.
(ix) External exit door of staircase enclosure at ground level shall open directly to the open spaces or can be reached without passing through any door other than a door provided to form a draught lobby.
(x) The exit sign with arrow indicating the way to the escape route shall be provided at a height of 0.5 meter from the floor level on the wall and shall be illuminated by electric light connected to corridor circuits. All exit way marking signs shall be flushed with the wall and so designed that no mechanical damage shall occur to them due to moving of furniture or other heavy equipment's. Further all landings of floor shall have floor indication boards indicating the number of floor. The floor indication board shall be placed on the wall immediately facing the flight of stairs and nearest to the landing. It shall be of size not less than 0.5 meter X 0.5 meter and it shall be prominently on the wall facing the staircase.
(xi) In case of single staircase it shall terminate at the ground floor level and the access to the basement shall be by a separate staircase. The second staircase may lead to basement levels provided the same is separated at ground level by either a ventilated lobby with discharge points at two different ends or through enclosures with fire resistance rating door (Table 1, Part IV of the National Building Code of India revised time to time) or through a fire protected corridor.
(3) Lifts: General requirements of lifts shall be as follows:
(i) All the floors shall be accessible for 24 hours by the lifts. The lifts provided in the buildings shall not be considered as a means of escape in case of emergency. In a dual line arrangement (lifts opposite to each other) the lobby may be between 1.5 times to 2.5 times the depth of one car. For in-line (single line) arrangements the lobby may be typically half of the above recommendations.
(ii) Grounding switch, at ground floor level, to enable the fire service to ground the lift shall also be provided.
(iii) The lift machine room shall be separate and no other machinery shall be installed there in.
(iv) Walls of lift enclosures and lift lobby shall have fire rating of 2 hour; (National Building Code of India); lifts shall have a vent at the top of area not less than 0.2 square meter.
(v) Lift car door shall have a fire resistance rating of 1 hour.
(vi) Lift lobby doors in lift enclosures shall have fire resistance as per relevant provision of the National Building Code of India.
(vii) Collapsible gates shall not be permitted for lifts and shall have solid doors with fire resistance of at least 1 hour.
(viii) If the lift shaft and lobby is in the core of the building, a positive pressure between 25 and 30 Pa shall be maintained in the lobby and a positive pressure of 50 Pa shall be maintained in the lift shaft. The mechanism for pressurization shall act automatically with the fire alarm; it shall also be possible to operate this mechanically.
(ix) Lifts if communicating with the basement, the lift lobby of the basements shall be pressurized as suggested in Annexure-IV (Fire Protection and Fire Safety Requirements) with self-closing door with fire resistance rating. Telephone or other communication facilities shall be provided in lift cars and to be connected to fire control room for the building.
(x) Exit from the lift lobby, if located in the core of the building, shall be through a selfclosing fire door of half an hour fire resistance.
(xi) Suitable arrangements such as providing slope in the floor of lift lobby shall be made to prevent water used during firefighting etc., at any landing from entering the lift shafts.
(xii) A sign shall be posted and maintained on every floor at or near the lift indicating that in case of fire, occupants shall use the stairs unless instructed otherwise. The sign shall also contain a plan for each floor showing the locations of the stairways. Alternate source of power supply shall be provided for all the lifts through a manually operated changeover switch.
(xiii) The National Building Code of India, Chapter 4 Fire and Life Safety, Clause 4.10 Pressurization of Staircases (Protected Escape Routes) may be followed for Pressurization Specifications of various building components.
(i) The ramp to basement and parking floors shall not be less than 7.2 meters wide for two way traffic and 4 meter wide for one way traffic, provided with Gradient of 1:10 for cars and 1:15 for heavy vehicles. At curved portions of the ramp or for circular ramps the slope shall not be more than 1:12.
(ii) Ramp may also be provided in setback area which can be sloped considering unhindered movement of fire Engine and in no case the gradient shall be less than 1:10.
(iii) All structural design/safety aspects shall be complied per latest BIS Codes and National Building Code of India along with consideration of weight of Fire Engine and its maneuverings.
(iv) The minimum width of the ramps in hospitals shall be 2.4 meters for stretcher and not for vehicular movement
(v) In this case Handrails shall be provided on both sides of the ramp.
(vi) Ramps shall lead directly to outside open space at ground level or courtyards or safe place.
(i) Exit corridors and passageways shall be of width not less than the aggregate required width of exit doorways leading from them in the direction of travel to the exterior.
(ii) The minimum width of a corridor in a residential building shall be 1.0 meter for single loaded and 1.8 meters for double loaded and in all other buildings shall be 1.5 meters.
(iii) Where stairways discharge through corridors and passageways, the height of corridors and passageways shall be not less than 2.4 meters. (iv) All means of exit including staircases lifts lobbies and corridors shall be ventilated.
(6) Glass Facade/ Service Ducts/Shafts/ Refuge Area/ Vents
(i) An Opening to the glass facade of min. width 1.5 meters and height 1.5 meters shall be provided at every floor at a level of 1.2 meters from the flooring facing compulsory open space as well as on road side. Construction that complies with the fire rating of the horizontal segregation and has any gap packed with a noncombustible material to withstand thermal expansion and structural movement of the walling without the loss of seal against fire and smoke.
(ii) Mechanism of Opening: The openable glass panel shall be either left or right shall have manual opening mechanism from inside as well as outside. Such openable panels shall be marked conspicuously so as to easily identify the openable panel from outside.
(iii) Fire seal to be provided at every floor level between the external glazing and building structure.
(iv) The glazing used for the facade shall be of toughened (tempered) safety glass as per I.S. 2553.
(v) To avoid fire propagation vertically from one floor to another floor, a continuous glass must be separated internally by a smoke/ fire seal which is of non-combustible material having a fire resistance rating of not less than 2 hours.
(vi) Service ducts and shafts shall be enclosed by walls and doors with fire resistance rating. All such ducts or shafts shall be properly sealed and stopped fire ingress at all floor levels.
(vii) A vent opening at the top of the service shaft shall be provided having an area between one- fourth and one-half of the area of the shaft.
(viii) Glass quality and Practice of use of Glass in buildings shall have to be in conformity with the BIS codes as given in Table 2 herein contained.
|Table No. 2: Glass quality and Use of glass in buildings
||2553 (Part 1): 1990
||Specification for safety glass: Part 1 General purpose (third revision)
||Specification for flat transparent sheet glass (third revision)
||Specification for silvered glass mirrors for general purposes (second revision)
||Specification for figured rolled and wired glass (first revision).
||Specification for transparent float glass.
||16231 Part 1
||General methodology for selection
||16231 Part 2
||Energy and Light
||16231 Part 3
||Fire and Loading
||16231 Part 4
||Safety related to Human Impact
(7) Building Services
(i) Staircase and Corridor Lighting
(a) The staircase and corridor lighting shall be on separate service and shall be independently connected so as it could be operated by one switch installation on the ground floor, easily accessible to firefighting staff at any time irrespective of the position of the individuate control of the light points, if any.
(b) Staircase and corridor lighting shall also be connected to alternate supply from parallel high-tension supply or to the supply from the stand-by generator.
(c) Emergency lights shall be provided in staircase and corridor or passageway, horizontal exits, refuge area; and all wires and other accessories used for emergency light shall have fire retardant property.
(ii) Electrical Services
(a) The electric distribution cables or wiring shall be laid in separate duct which shall be sealed at every floor with non-combustible materials having the same fire resistance as that of the duct. Low and medium voltage wiring running in shaft and in false ceiling shall run in separate conduits.
(b) Water mains, telephone cables, intercom cables, gas pipes or any other service line shall not be laid in the duct for electric cables. Use of bus ducts/solid rising mains instead of cables is preferred.
(c) The provision of dedicated telecommunication ducts for all new building proposals is mandatory for conveyance of telecommunication and other data cables.
(d) Separate circuits for water pumps lifts, staircases and corridor lighting and blowers for pressurizing system shall be provided directly from the main switchgear panel.
(iii) Alternate Source of Electric Supply:
A stand-by electric generator shall be installed to supply power to staircase and corridor lighting circuits, fire lifts, the stand-by fire pumps, pressurization fans and blowers, smoke extraction and damper system in case of failure of normal electric supply. The generator shall be capable of taking starting current of all the machines and circuits stated above simultaneously. If the stand-by pump is driven by diesel engine, the generator supply need not be connected to the stand-by pump.
(iv) Air-conditioning: Air-conditioning shall conform to the following:
(a) Escape routes like staircases, common corridors, lift lobbies. shall not be used as return air passage.
(b) The ducting shall be constructed of substantial gauge metal in accordance with good practice.
(c) Wherever the ducts pass through fire walls or floors, the opening around the ducts shall be sealed with materials having fire resistance rating of the compartment.
(d) Where duct crosses a compartmen which is fire rated, the ducts shall be fire rated for same fire rating. Further depending on services passingaround the duct work, which may get affected in case of fire temperature rising, the ducts shall be insulated.
(e) Metallic ducts shall be used even for the return air instead of space above the false ceiling.
(f) Where plenum is used for return air passage, ceiling and its fixtures shall be of non-combustible material.
(g) The materials used for insulating the duct system (inside or outside) shall be of non-combustible material; glass wool shall not be wrapped or secured by any material of combustible nature.
(h) Air ducts serving main floor areas, corridors, shall not pass through the staircase enclosure.
(i) The air-handling units shall be separate for each floor and air ducts for every floor shall be separated and in no way inter-connected with the ducting of any other floor. (v) If the air-handling unit serves more than one floor, the recommendations given in clause
(v) shall be compiled with, in addition to the conditions given below:
(a) Proper arrangements by way of automatic fire dampers working on smoke detector / or fusible link for isolating all ducting at every floor from the main riser shall be made.
(b) When the automatic fire alarm operates, the respective air-handling units of the air-conditioning system shall automatically be switched off.
(c) The vertical shaft for treated fresh air shall be of masonry construction.
(d) The air filters of the air-handling units shall be of non-combustible materials or fire rated.
(e) The air-handling unit room shall not be used for storage of any combustible materials.
(f) Inspection panels shall be provided in the main trunking to facilitate the cleaning of ducts of accumulated dust and to obtain access for maintenance of fire dampers.
(g) No combustible material shall be fixed nearer than 150 mm to any duct unless such duct is properly enclosed and protected with non-combustible material (glass wool or spyglass with neoprene facing enclosed and wrapped with aluminum sheeting) at least 3.2 mm thick and which would not readily conduct heat.
(a) When transformers are housed in the building below the ground level it shall be necessarily in the first basement in separate fire resistance room of 4 hours rating. Transformer shall be dry type and shall be kept in an enclosure with walls, doors and cut-outs having fire resistance rating of 4 hour. The room shall necessarily be at the periphery of the basement having separate and direct access from open area at ground floor through a fire escape staircase. The entrance to the room shall be provided with a steel door of 2 hours fire rating. A curb of a suitable height shall be provided at the entrance in order to prevent the flow of oil from ruptured, transformer into other parts of the basement. The switchgears shall be housed in a separate room separated from the transformer bays by a fireresisting wall with fire resistance not less than 4 hours.
(b) The transformer shall be protected by an automatic foam sprinkler system. When housed at ground floor level it/they shall be cut-off from the other portion of premises by Fire Resisting Walls of 4 hours rating.
(c) A tank of RCC construction of adequate capacity shall be provided at lower basement level to collect the oil from the catch pit in case of emergency. The pipe connecting the catch-pit to the tank shall be of noncombustible construction and shall be provided with a flame-arrester.
(d) The electric sub-station shall be located in a separate building in accordance with sub-rule (1) of rule 68 and clause (a) of sub-rule (1) of rule 64 of the Indian Electricity Rules, 1956.
(e) In case this is not practically possible due to site conditions, the substation shall be located on the ground floor. As far as possible sub-station shall not be installed in a basement, for such situations special provisions like mechanical ventilation, wherever required, cable ducting, cable trays, top/bottom entry of HV/LV cable, hooks on Transformer(s) and HV panels, adequate fire detection and fire-fighting arrangement, adequate drainage, effective measures to prevent flooding shall be provided. Adequate precautions shall also be taken for water proofing to prevent seepage of water. A ramp shall also be provided with a slope, not steeper than 1 in 7, for easy movement of equipments to and from sub-station.
(vii) Fire regulations
The installations shall be carried out in conformity with the local regulations and rules made thereunder wherever they are in force. At other places the National Building Code of India shall be followed.
(viii) Gas supply:
(a) Town Gas / L.P. Gas Supply Pipes - Where gas pipes are run in buildings, the same shall be run in separate shafts exclusively for this purpose and these shall be on external walls away from the staircases. There shall be no interconnection of this shaft with the rest of the floors.
(b) LPG distribution pipes shall always be below the false ceiling. The length of these pipes shall be as short as possible. In the case of kitchen cooking range area, apart from providing hood, covering the entire cooking range, the exhaust system shall have to be designed to take care of 30 cu.m per minute per square meter of hood protected area. It must have grease filters using metallic grill to trip oil vapours escaping into the fume hood.
(c) For large/commercial kitchens all wiring in fume hoods shall be of fiberglass insulation. Thermal detectors shall be installed into fume hoods of large kitchens for hotels, hospitals and similar areas located in high rise buildings. Arrangements shall be made for automatic tripping of the exhaust fan in case of fire.
(d) When LPG is used, the same shall be shut off. The voltage shall be of 24 V or 100 V DC operated with the external rectifier. The valve shall be of the hand re-set type and shall be located in an area segregated from cooking ranges. Valves shall be easily accessible. The hood shall have manual facility for steam or carbon dioxide gas injection, depending on duty condition; and Gas mters shall be housed in a suitably constructed metal cupboard located in a well-ventilated space, keeping in view the fact that LPG is heavier than air and town gas is lighter than air.
(ix) Boiler Room:
Further, the following additional aspects may be taken into account in the location of Boiler/Boiler Room:
(a) The boiler shall not be allowed in sub-basement but be allowed in the first basements away from the escape routes.
(b) The boilers shall be installed in a fire resisting room of 4 hours fire resistance rating, and this room shall be situated on the periphery of the basement. Catch pit shall be provided at the low level. Entry to this room may be provided with a composite door of two hour fire resistance.
(c) The boiler room shall be provided with fresh air inlets and smoke exhausts directly to the atmosphere.
(d) Foam inlets shall be provided on the external walls of the building at the ground floor level to enable the fire services to use foam in case of fire.
(e) The furnace oil tank for the boiler, if located in the adjoining room shall be separated by fire resisting wall of 4 hour rating. Entry to this room shall be provided with a composite door of 2 hour fire resistance. A curb of suitable height shall be provided at the entrance in order to prevent the flow of oil into the boiler room in case of tank rupture.