Proposed Single-Family Zoning Reform Would Have a Big Footprint in California

The Terner Center for Housing Innovation has published a detailed analysis of SB 1120, a law proposed in California as the latest attempt to ease development restrictions and spur housing development in the infamously expensive state.

The effect of SB 1120 would be similar to similar planning innovations in the cities of Minneapolis and Portland, as well as the state of Oregon: to end the exclusionary regulations of vast swaths of single-family zoning. 

As written, SB 1120 affects single-family parcels in two ways that could ultimately lead to up to four homes on lots where currently only one exists. First, the proposed legislation would allow existing single-family homes to be converted into duplexes. Second, the proposed legislation would allow single-family parcels to be subdivided into two lots, while also allowing for a new, two-unit building to be constructed on the newly formed lot.

While the paper predicts the potential for the proposed law to facilitate the construction of a significant number of new units in the state, the final total would be determined by local regulations and financing opportunities. 

The analysis includes an assessment of the number of parcels statewide that would be eligible to split as defined by the bill's current language. According to the paper, millions of parcels would be eligible to split— 5,977,061 to be exact. In a state with about 12.5 million parcels in total, that would be a significant amount of potential change.