Encroaching projections, including, amongst others, veranda roofs, balconies, landings, stairways, flagpoles and gantries for cranes, the erection of which is permitted by the local authority, shall—

a) Not be supported by encroaching columns;

b) Be constructed of non-combustible material or be provided with protection having a fire-resistance rating, determined according to the provisions of Chapter 11, of not less than half an hour;

c) Subject to the provisions of section 7, be not less than 3 meters above the level of the footway measured to the underside of the lowest portion;

d) Be at every point at least 300 millimeters back from the vertical line through the edge of the kerb;

e) Provide for disposal of rain-water, in accordance with section 9.