Except as hereinafter provided:
A. No person shall use any premises for use other than those permitted in the district in which such premises are located.
B. No building shall be erected unless it conforms to the regulations for the district in which such premises are located.
C. No building shall be enlarged, structurally altered or moved unless such enlargement, structural alteration or moving conforms to the regulations for the district in which the premises are located.
D. Every building hereafter erected, enlarged or structurally altered shall be located on a lot as defined in this title and in no case shall there be more than one main building on one lot. Land that is part of one lot and that is not in excess of the area requirements for that lot shall not be used to satisfy the area requirements of any other lot. (Prior code § 11-2-5)