Accessory dwelling units and junior accessory dwelling units.

Senator McNerney's legislation revises California's regulatory framework for accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs), establishing new statewide standards for local permitting processes and development requirements. The bill redefines JADUs as units no larger than 500 square feet of interior livable space located entirely within single-family residences, while maintaining existing ADU provisions.

Local agencies must now process both ADU and JADU applications through a streamlined ministerial review, with 15-day deadlines for completeness determinations and 60-day windows for final decisions. The legislation requires agencies to provide detailed written explanations when applications are deemed incomplete or denied, along with instructions for remedying deficiencies. Applications not acted upon within these timeframes receive automatic approval.

The measure implements new fee limitations, prohibiting impact fees on ADUs under 750 square feet and JADUs under 500 square feet of interior livable space. Larger ADUs may only be charged impact fees proportional to the primary dwelling's square footage. Local agencies cannot require new utility connections or impose related fees for ADUs and JADUs unless constructed alongside new single-family homes.

Local ordinances must be submitted to the Department of Housing and Community Development within 60 days of adoption for compliance review. Ordinances that conflict with state standards or are not submitted timely become void, defaulting to the state's ministerial approval requirements. While local agencies retain authority to adopt less restrictive requirements, the bill's provisions explicitly supersede more stringent local regulations.