Section 52(7)(c) in Tamil Nadu Combined Development and Building Rules, 2019
(c)Other requirements. - Every bath room or water closet shall:(i)be so situated that at least one of its walls shall open to external air;(ii)not be directly over or under any room other than another water closet,(iii)washing place, bath or terrace, unless it has a water-tight floor;(iv)be enclosed by walls or partitions and the surface of every such wall or partitions shall be finished with a smooth impervious material to a height of not less than 1m above the floor of such a room;(v)be provided with an impervious floor covering, sloping towards the drain with a suitable grade and not towards varandah or any other room; and have a window or ventilator, opening to a shaft or open space, of area not less than 0.3sq.m.(vi)the door of the water closet or bath not to be directly opened to a kitchen