(2)No person shall occupy, or permit any other person to occupy, any such building or use, or permit any other person to use, any building or a part thereof affected by any such work until permission has been granted by the Municipal Commissioner or the Executive Officer in this behalf in accordance with the rules and the regulations made under this Act:Provided that if the Municipal Commissioner or the Executive Officer fails, within a period of thirty days of receipt of the notice of completion, to communicate his refusal to grant such permission, such person may make a representation in writing to the Mayor or the Chairperson concerned.Municipal Building Code