Section 23(4)(ix) in The Chennai City Corporation Building Rules, 1972
(ix)Every chimney or flue intended for use in connection with any furnace or copper, steam boiler or close fire constructed for any purpose of trade, business or manufacture or which may be intended for use in connection with any cooking range or cooking apparatus of a building occupied as a hotel, tavern or eating house shall be surrounded with fire bricks at least eleven and a half centimetres thick for a distance of at least three metres in height from the floor on which such furnace of copper, steam boiler, close fire cooking range or cooking apparatus is constructed or placed;