No person shall, without the written permission of the Commissioner, or otherwise than in conformity with the conditions, if any, of such permission—
         (a) use or permit to be used for human habitation any part of a building not originally erected or authorised to be used for that purpose or not used for that purpose before any alteration has been made therein by any work executed in accordance with the provisions of this Act and of the bye-laws made thereunder;
         (b) change or allow the change of the use of any land or building;
         (c) convert or allow the conversion of one kind of tenement into another kind.