(a) Every staircase shall be suitably lighted and properly ventilated through an external wall.
(b) The minimum clear width of staircases in case of domestic building shall not be less than 0.9 m.
(c) The minimum clear width of staircases in case of public building shall not be less than 1.2 m for every 300 persons who are expected to use the building. The furthest corner of the building shall not be more than 18 m distance from the staircase.
The minimum rise and minimum breadth of tread of staircases will be as follows:
Maximum rise Minimum-tread-of obstruction Domestic building 175 mm 225 mm Public building 150 mm 275 mm Hospital& Auditorium 150 mm 300 mm
(d) Interior staircase may be constructed with fire resistant materials throughout.
(e) A staircase shall not be arranged around a lift shaft, unless the latter is entirely enclosed with material with fire resistant rating and that for type of construction itself. For building more than 15.8 m in height, the staircase location shall be to the satisfaction of the Authority regulating fire safety and the distance from the furthest corner of the building to the staircase should not be more than 18 m.
(f) The minimum head room in a passage under the landing or under the staircase, if provided shall be 2.2 m.
(g) All buildings which are more than 15.8 m in height and all buildings used as educational, assembly, institutional, industrial, store and hazardous occupancies and mixed occupancies having area more than 500 sq. m. on every floor shall have minimum two staircases. At least one of them be on external wall of buildings and shall open directly to the exterior/ interior open space as to an open area of safety. The provision of alternative staircase shall be subject to the requirement of travel distance being complied with.
(h) The use of spiral staircase (fire escape) shall be limited to a building
12.8 m in height and to be connected with external balconies and shall be designed to give adequate head room.
NEW REVISED BUILDING BYELAWS FOR GUWAHATI METROPOLITAN AREA-2006 Guwahati Metropolitan Dev. Authority Page No. [33]
(i) Ramps other than for parking floor shall have slope of not more than 1:10 provided that in case of public office, hospitals, slope of ramps shall not be more than 1:12. The minimum width of the ramps for hospitals should not less than 2.0 m.