The property development standards set forth in this chapter shall apply to all uses of land and the construction, alteration, enlargement, use, maintenance and occupancy of buildings and structures in the R-3-C zone, except that any lot shown on an official subdivision map duly approved and recorded or any lot for which a bona fide deed had been duly recorded by June 21, 1965 may be used as a building site.
(`78 Code, § 17.26.050.)