Except as hereinafter provided in this chapter:
(a) No private or public housing shall be permitted in any industrial zone, except as an accessory use for a custodian or watchman.
(b) No building, structure, or land shall hereafter be used or occupied and no building or structure or part thereof shall hereafter be erected, moved, altered, reconstructed, or enlarged for any purpose except in conformance with the regulations herein specified for the zoning district in which it is located.