HSC §17958.1: (a) Notwithstanding Sections 17922, 17958, and 17958.

(a) Notwithstanding Sections 17922, 17958, and 17958.5, a city, county, or city and county may, by ordinance, permit efficiency units for occupancy by no more than two persons which have a minimum floor area of 150 square feet and which may also have partial kitchen or bathroom facilities, as specified by the ordinance. In all other respects, these efficiency units shall conform to minimum standards for those occupancies otherwise made applicable pursuant to this part. (b) “Efficiency unit,” as used in this section, has the same meaning specified in the International Building Code of the International Code Council, as incorporated by reference in Part 2 of Title 24 of the California Code of Regulations. (c) A city, county, or city and county shall not do any of the following: (1) Limit the number of efficiency units in an area zoned for residential use and located within one-half mile of public transit or where there is a car share vehicle located within one block of the efficiency unit. (2) Limit the number of efficiency units in an area zoned for residential use and located within one mile of a University of California or California State University campus. (3) For purposes of this subdivision, any requirements related to density, setbacks, lot coverage, or height restrictions established by local ordinance are not considered a limit on the number of efficiency units.