In addition to those uses permitted in this district with which it is combined, one secondary dwelling unit per building site is permitted on parcels zoned for not more than one dwelling and having one but no more than one existing dwelling unit on the parcel subject to the following requirements:

    A.    A two-car garage or area equivalent for two legal parking spaces and a two-car driveway apron or area equivalent for the additional parking spaces must be present on the property.

    B.    The attached secondary unit shall have a direct external entry and shall be limited to maximum of six hundred forty (640) square feet in area. In all other respects the regulations of the R-1 district shall remain the same.

    C.    A detached secondary unit shall be limited to one story, fifteen (15) feet in height, a minimum of ten feet from the existing dwelling. The detached secondary unit shall be clearly subordinate to existing principal single-family dwelling by size, appearance and location and shall be located to the rear of the existing dwelling. In all other respects the regulations of the R-1 district shall remain the same. (Prior gen. code § 8-44.10)