A nonconforming residential building in a residential zone that has a nonconforming side yard or rear yard setback and that was constructed prior to August 30, 1968, may be enlarged, remodeled or structurally altered provided such enlargement, remodel or structural alteration itself conforms in all respects to the regulations specified by Article 26, 26.1 or 26.2 of this Chapter for the zone in which such building is located. Nonconforming buildings constructed on or after August 30, 1968, may be enlarged subject to regulations contained in Articles 26 or 26.1. Otherwise, it is unlawful to enlarge, extend or structurally alter any nonconforming building. For buildings constructed prior to August 30, 1968, where the structure is nonconforming for a side yard or rear yard property line setback only, a one-time expansion may be approved subject to regulations contained in Section
12-98.16, to allow the extension of the non-conforming linear setback no more than fifteen percent, or not more than fifteen feet, which ever is greater provided that no linear expansion shall be approved for a nonconforming building setback that is less than three feet. Any enlargement, remodel or structural alteration under this Section of the Code shall be limited to a one time approval under this Section for the full life of the building's use and required residential parking, Building Code regulations, Fire Code regulations, and all other applicable regulations that are referenced or inferred by this Chapter, shall be applicable. An addition that exceeds a one-time fifteen percent expansion, or more than fifteen feet for a linear expansion, shall be processed according to Section
12-60(B)(6) or other applicable Code section.