Section 22 in Punjab Urban Planning and Development Authority Building Rules, 2013
22. Minimum height of room, verandah and light ventilation.
(1)The height of a habitable room shall not be less than 2.70 metres and the mean height of a water closet, bath room, store room, gallery, verandah and mezzanine floor shall not be less than 2.25 metres and the clear headroom in any staircase shall not be less than 2.25 metres.(2)Notwithstanding the obstruction by the projection and compound wall, habitable room shall have the opening either directly or through an open verandah or courtyard, into an open space having a minimum width of 2.5 metres and the total aggregate an open able area in the form of windows, ventilators, glazed doors or other apertures shall not be less than one-tenth of the floor area of the room.
