No building shall hereafter be erected and no existing building shall be moved, structurally altered, added to, enlarged, or rebuilt, nor any land be designed and used or intended to be used, for any purpose other than those permitted in this chapter, nor shall any open space contiguous to any building be encroached upon or reduced in any manner, except in conformity with the yard, lot area, building location, percentage of lot coverage, and off-street parking space specified in this chapter, and such other regulations designated in the schedule appended hereto, constituting a part of Article III of this chapter, for the zone in which such building or space is located. In the event of 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 of such building shall thereupon become null and void.