No permitted principal use shall be commenced, erected, constructed or allowed unless site plan review and approval has occurred. The Planning Commission shall have the right to approve all setbacks, minimum of floor space requirements, and locations of all buildings and improvements, provided that setbacks shall be at least the same as those required in the C-1 commercial district. No buildings or improvements shall be allowed, except essential services, in any setback, side yard or rear yard in C-2 Commercial Districts.