Section 30(2)(b) in Faridabad Complex Administration Building Rules, 1989
(b)Shall be provided for the purpose of light and ventilation with windows, ventilators or other apertures which shall have a total floor area of not less than ¼th of the total floor area of the room. All doors and windows or other apertures shall open directly or through a verandah or to a permanent open space or an open space above the building or not less than 1.8 metres in width.