No building shall hereafter be erected and no existing building shall be moved, structurally altered, added to or enlarged, rebuilt, nor shall any land be designed, used, excavated or intended to 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 as set forth by the Schedule of Limitations appended hereto and constituting a part of this chapter. Nor shall any open space contiguous to any building be encroached upon or reduced in any manner, except in conformity to the yard, lot area, building location, percentage of lot coverage, off-street parking space, and such other regulations designated in this chapter and for the zone in which such building or space is located. In the event of any such unlawful encroachment or reduction, such building shall be deemed to be in violation of the provisions of this chapter and the Certificate of Occupancy for such building shall thereupon become null and void.