California ADU Law Updates: AB 956 and SB 1117
Updated August 2026
Two California bills affecting accessory dwelling units passed the state Legislature in August 2026. AB 956 addresses the number of detached ADUs allowed on qualifying single-family properties, while SB 1117 addresses how impact fees may be calculated for larger ADUs.
As of August 31, 2026, neither bill had been signed into law.
AB 956: Two Detached ADUs on Qualifying Properties
Under existing California law, local agencies must provide ministerial approval for one detached, new-construction ADU on a qualifying lot with an existing or proposed single-family dwelling.
AB 956 would increase that number from one to two detached, new-construction ADUs when applicable state and local requirements are met.
The enrolled bill also states that a local agency would not be required to approve a JADU on the same lot where two detached, new-construction ADUs have been built.
AB 956 passed the California Senate on August 25, 2026. The Assembly concurred with the Senate amendments on August 27, sending the bill into the enrollment process.
SB 1117: Impact Fees for Larger ADUs
Existing California law generally exempts ADUs smaller than 750 square feet from impact fees. Impact fees for larger ADUs must generally be charged proportionately in relation to the square footage of the primary dwelling.
SB 1117 would change the calculation for certain ADUs larger than 750 square feet. For the first and second ADUs on a property, applicable impact fees would be based only on the interior livable space exceeding 750 square feet.
SB 1117 passed the Assembly on August 20, 2026. The Senate concurred with the Assembly amendments on August 25, and the bill was presented to the governor on August 30.
What California Property Owners Should Know
AB 956 and SB 1117 could affect the number and cost of ADUs that may be built on qualifying California properties. However, passage by the Legislature does not make a bill law. Both measures still require action by the governor as of the end of August 2026.
ADU eligibility also depends on the individual property and applicable local requirements, including zoning, setbacks, utilities, access, drainage, fire safety, and site conditions.
California ADU Law Resources
- AB 956: Official bill text, votes and status
- SB 1117: Official bill text, votes and status
- California Department of Housing and Community Development: Accessory Dwelling Units
- California HCD Housing Law Fact Sheets
- California Legislative Information
Disclaimer: This article is for informational purposes only. For the most current California ADU legislation, visit the California Legislative Information website and confirm local requirements with your planning department before beginning your project. You may also contact the Perpetual Homes ADU team for a consultation.
