Section 52(17) in Tamil Nadu Combined Development and Building Rules, 2019
(17)Stairways Requirements. - (a) Minimum width of staircase shall be:(i)(a)Ordinary Residential buildings............. 0.75 m(b)Other Residential buildings................ 0.90 m(ii)Assembly buildings like :Auditoria, assembly halls......................... 2.00 m(iii)All other buildings..................................... 1.50 m(iv)Educational institutions............................ 2.00 m(b)Minimum tread - The minimum width of tread without nosing shall be 250mm for residential buildings. The minimum width of tread for other buildings shall be 300mm. In case of spiral staircases, it shall have the above minimum tread width at the outer end.(c)Maximum riser - The maximum height of riser shall be 190mm for residential buildings and 150mm for other buildings and these shall be limited to 15 per flight.(d)The minimum headroom in a passage under the landing of a staircase shall be 2.2m. The minimum clear headroom in any staircase shall be 2.2m.
