Section 15 in Tamil Nadu District Municipalities Building Rules, 1972
15. Stairs.
(1)All storeyed buildings shall be provided with sufficient number of staircases, depending on the number of occupants using the building, in suitable locations as may be accessible to the occupants within a distance of not more than 18 metres.(2)All stairs shall comply with the following requirements: -(a)Width of stairs. - The clear width of all stairways shall not be less than 60 centimetres excluding the handrails.(b)Headroom. - All stairways shall have at least 2.1 metres of clear headroom, measured perpendicularly from the nosing.(c)Treads and risers. - Treads and risers shall be so proportioned that the sum of two risers and a tread width is not less than 60 centimetres and more than 62.5 centimetres. No riser shall be more than 17.5 centimetres and no tread width less than 25 centimetres. There shall be no variation in the width of treads or the height of risers in any one flight of stairs. No stairway should, ordinarily, be permitted cutting across any window. The surface material of stairs, treads and landings shall be such as not to involve undue danger of slipping.(d)Landings. - No stairway shall have a height of more than 3.75 metres between landings nor less than two risers between consecutive landings, the landings shall have a dimension not less than the width of stairs, measured in the direction of the run.(e)Rails. - Stair shall have walls or well secured balustrades or guards on both sides. Handrails shall be placed not less than 75 centimetres and not more than 1 metre above the nosings of the treads.(f)Space under stairs. - The space beneath any stairway built in whole or in part of combustible materials except handrails shall be left entirely open.(g)Ventilation for staircases. - Every staircase shall be lighted and ventilated to the satisfaction of the executive authority from an open space.There shall be provided, a window or windows or ventilator or ventilators for an aggregate area of at least 1.5 square metres in each floor in such of the wall of the staircase room as about 1.75 metres open space to light and ventilate such staircase. The above provision can be dispensed with when an open well for light and ventilation within the space enclosed by the stair way and its landings is proposed to be provided the least horizontal dimensions of which are equal to twice the width of the staircase provided that there shall be in the roof directly over such staircase well a ventilating sky light provided with ridge ventilators or else, such sky lights shall be provided with fixed or movable louvers to the satisfaction of the executive authority. The glassed roof of the skylight shall not be less than 3.75 square metres in area. No lift or any other fixture shall be erected in such staircase well.(h)Passage giving access to staircase. - Even passage in a building in the ground floor shall, in no part, be less than the width of the staircase of such building to which it gives access:Provided that if only one such passage gives access to more than one staircase, its minimum width shall be equal to the width of such staircases plus one half of the total width of the remaining staircases.(3)Minimum width of doors, corridors or passage. - No doorway or corridor or passage serving as exit to a building shall be less than 1 metre in width. The doors of kitchen, bath and flush out latrine shall not be less than 0.60 metre clear in width and the passage leading to the same shall not be less than 0.75 metres:[Provided that this rule shall not apply to the plots in respect of the layout approved by the Director of Town and Country Planning or [Chennai] [Added by G. O. Ms. No. 3. R.D. & L. A., dated 2nd January 1982.] Metropolitan Development Authority in respect of [Chennai] [Substituted for the word 'Madras' by the City of Madras (Alteration of Name) Act, 1996 (Tamil Nadu Act 28 of 1996).] Metropolitan Area or by the Officers to whom such powers are delegated by them, for development by the Tamil Nadu Housing Board, the Tamil Nadu Slum Clearance Board and similar Quasi-Government Agencies.]
