(1)No person shall, without the permission, in writing, of the Municipal Commissioner or the Executive Officer or otherwise than in conformity with the conditions of such permission, -(a)use, or permit to be used, for the purpose of human habitation any building or part thereof not originally erected or authorized to be used for such purpose,(b)change, or allow the change of, the use of a building for any purpose other than that specified in the approved plan,(c)change, or allow the change of, the use of any building erected before the commencement of this Act contrary to the use for which such erection was originally approved or to the use to which such building was actually put,(d)convert, or allow the conversion of, a tenement within a building to an occupational use, other than the use intended in the original approved plan, or materially alter, enlarge, or extend such use.
