When a new building is constructed or a building is structurally altered or the use is substantially changed, the minimum off-street parking and loading space to be provided on the lot shall be as indicated in Larkspur Municipal Code Chapter 18.56 except that for residential units above first-story commercial the parking requirement shall be one parking space per dwelling unit. (Ord. 1030 § 2(12), 2018; Ord. 939 § 10, 2004; Ord. 313 § 2, 1965; Ord. 295 § 139, 1962)