No land shall be occupied or used, and no structure erected, reconstructed or structurally altered shall be occupied or used, in whole or in part, for any purpose whatsoever, until a certificate of occupancy shall have been issued by the Code Enforcement Officer stating that the structure and use appear to comply with all applicable provisions of this Zoning Law. No change in any use shall be made to any structure or part thereof, except in conformance with a certificate of occupancy issued by the Code Enforcement Officer.