Section 44 in The Building Regulation in Respect of Lands Covered by the Calcutta Thika Tenancy (Acquisition and Regulation) Act, 1981
44. Ventilation of inhabited rooms :
(a)For purpose of ventilation, every room in a masonry building or permanent structure shall have window and doors, opening directly into the external air or into an open verandah, having opening not less than 10 per cent of the floor area of rooms.(b)Width of each flight of stair shall not be less than 90 cm.
