No building or structure shall be constructed or enlarged unless the following yards are provided and maintained in connection with such building.

    A.    Front Yard. Each lot upon which a building is constructed shall have a front yard of not less than fifty (50) feet.

    B.    Side Yard. No side yard shall be required, except for a lot which abuts upon an R district, or upon an alley separating this district from an R district. There shall then be provided a side yard equal to one-half the front yard required in the abutting R district, but in no case less than twenty (20) feet.

    C.    Rear Yard. There shall be a rear yard of not less than twenty (20) feet; provided, however, that a one-story accessory building may be located thereon; except for the five feet adjacent and parallel to the rear lot line or alley line, for the parking of motor vehicles and the unloading and loading of vehicles under roof. (Ord. 742 § 1 (part), 1989: prior code § 40-7-3(E))