No building shall hereafter be erected and no existing building shall be moved, structurally altered, rebuilt, added to or enlarged, nor shall any land be used for any purpose other than those included among the uses listed as permitted uses in each zone by this chapter and meeting the requirements set forth in the appended schedule, nor shall any open space contiguous to any building be encroached upon or reduced in any manner, except in conformity to the area and bulk requirements, off-street parking requirements, and all other regulations designated in the schedule and this chapter for the zone district in which such building or space is located. In the event of any such unlawful encroachment or reduction, such building or use shall be deemed to be violation of this chapter and the certificate of occupancy shall become void.