In the R-1-D Zone:
A. Prior to issuance of a building permit for a second dwelling, the existing dwelling shall be improved for minimum Building Code standards.
B. There shall be no overlapping or reduction in existing yards related to existing structures.
C. No lot or parcel of land held under separate ownership at the time the ordinance codified in this title became effective shall be separated in ownership or reduced in size below the minimum standards provided for lots in the R-1 District. (Ord. 1000 § 18.20(F), 1955)