Section 117 in Kolkata Municipal Corporation Building Rules, 2009
117. Roof.
(1)The roof of a building-shall be so constructed or framed as to permit effectual drainage of the rain-water there from by means of sufficient rain water pipes of adequate size, wherever required, so arranged, joined and fixed as to ensure that the rain water is carried away from the building without causing dampness in any part of the walls or foundations of the building or those of an adjacent building.(2)The Municipal Commissioner may require rain-water pipes to be connected to a drain or sewer through a covered channel formed beneath any street to connect the rain-water pipe to a road gutter or in any other approved manner and/or rain water harvesting system in conformity with rule 144.(3)Rain-water pipes shall be affixed to the outside of the walls or through pipe shaft of the building or in recesses or chases cut or formed in such walls or in such other manner as may be approved by the Municipal Commissioner.(4)Every terrace on the/topmost storey of any building shall have a common access and shall not be subdivided.
