On January 1, 2022, a new State law (Cal. Gov’t Code section 65852.21, aka SB 9) took effect that allows up to two principal dwelling units on each single-family-zoned lot, with the option of creating an urban lot split in some qualifying situations that would allow up to two units on each resulting lot, for a total of four units. In addition to the housing options provided by ADUs and JADUs, SB 9 provides additional options for more substantial principal dwelling units within single-family zoning districts.

In short, SB 9 allows no more than a total of four units (two principal, two ADU/JADU) on an existing developed single-family zoned lot. This can be achieved two ways: (1) By building a second principal unit, plus one ADU and one JADU, or (2) if an existing lot is subdivided into two lots using the urban lot split provisions of SB 9, then no more than two units of any type are allowed on each resultant lot (two principal units each, or one principal unit each and one ADU or JADU each).

The documents below provide the City’s guidelines and policy on SB 9.