7. The walls and the roof (if any) of every privy and urinal shall be made of such materials as may be approved by the Commissioners:
Provided that—
(a) in the case of privies, the entire surface of the walls below the platform shall either be rendered in cement or be made as prescribed in clause (a) or clause (b) of rule 6.
Platform.
8. The platform of every privy or urinal must either be plastered with cement or be made of some water-tight nonabsorbent material as prescribed in rule 6.
Ventilation of privies in, or adjacent to, buildings.
9. Every privy or urinal situated in, or adjacent to, a building must have an opening, of not less than three square feet in area, in one of the walls of the privy, as near the top of the wall as may be practicable, and communicating directly with the open air.
Regulation of service privies constructed for use in combination with a moveable receptacle for sewage.
10. Every privy must be constructed in accordance with the following provisions:—
(a) the space beneath the platform of the privy must be of such dimensions as to admit of one or two moveable receptacles for sewage of a capacity not exceeding one cubic foot, being placed and fitted beneath the platform in such manner and position as will effectually prevent the deposit, otherwise than in such receptacle of any sewage falling or thrown through the aperture of the platform;