Governor Newsom Signs Three New Accessory Dwelling Unit Bills

Governor Gavin Newsom signed four new accessory dwelling unit bills into law in October, continuing California's annual trend of expanding ADU development opportunities for property owners.

The legislation includes AB 462, AB 1154, SB 9, and SB 543, with changes that are largely technical but require local jurisdictions to update their ordinances to remain compliant with state law.

AB 462, which took effect immediately as an urgency measure, addresses coastal development permits for ADUs in disaster-affected areas.

The bill modifies existing requirements that previously subjected ADUs in coastal zones to additional permitting processes beyond standard local approval procedures.

The other three bills take effect January 1, 2026, and build upon California's ongoing efforts to streamline ADU approval processes and increase housing options statewide.

The new legislation represents the latest evolution in California's ADU framework, which has undergone significant changes in recent years including mandatory 60-day approval timelines, allowances for selling ADUs separately from primary residences, and pathways to legalize unpermitted units.

Property owners and developers should consult with local planning departments to understand how these changes may affect their projects, as non-compliant local ordinances become null and void under state law.