With the passage of SB 9, California property owners in single-family neighborhoods now have the right to add a duplex to their property or split their lot. It’s one of many solutions policymakers have sought while they grapple with the challenges of the housing supply shortage and affordability crisis. This report explores whether these changes will be groundbreaking or gradual and how the City of Los Angeles can best implement the law to amplify its benefits while mitigating negative consequences for owners, residents, neighborhoods, and the city as a whole. It offers a set of insights and recommendations that, taken together, suggest that although SB 9 is an important step, it alone is not enough to improve affordability and racial equity without additional public and private intervention.

This report was corrected May 23, 2022. A previous version listed Helen Leung’s affiliation incorrectly in appendix B.