Own property in Southern California? Thought about building an ADU — maybe you call it a granny flat or in-law unit? There’s a new law that could change what your city can tell you to do. On September 29, 2026, Governor Newsom signed Assembly Bill 956 and Senate Bill 1117. These two laws push ADU protections into every zoning district that allows single-family homes. Cities and counties now have until the end of 2026 to update their local ADU rules. Miss that deadline? The city’s old ADU ordinance becomes null and void starting January 1, 2027. No legal effect at all. This hits homeowners, builders, landlords, and local governments across LA County, Orange County, San Bernardino County, and Riverside County. Our advice? Review your plans now. Talk to a real estate attorney before these rules kick in. Protect your rights — we handle the rest.
Background: What AB 956 and SB 1117 Mean
Here’s the basic idea. An ADU is a small, secondary unit built on a lot that already has a single-family home. Attached to the main house, a standalone structure, a converted garage — all fair game. California’s been passing ADU-friendly laws for years now, because let’s face it, the state’s in a housing crunch and something has to give.
How This Affects Property Owners and Builders in Southern California
This change matters for many people across the region, including homeowners in West Covina, Los Angeles, Anaheim, San Bernardino, Riverside, Ontario, and Pomona.
Homeowners planning an ADU. If your city’s ordinance becomes void on January 1, 2027, the rules that apply to your ADU permit application may change overnight. Setback requirements, unit size limits, parking rules, and owner-occupancy rules could shift from what your city’s planning department told you last month.
Landlords and property investors. If you plan to add a rental ADU for extra income, the void-ordinance rule could open up ADU options in zoning districts where they were not allowed before. This may increase the number of properties where an ADU is possible, but it may also create confusion about which rules apply during the transition.
Builders and developers. Contractors working on multiple ADU projects across different cities need to track each city’s compliance status separately. A project in Riverside may follow different transition rules than a project in Anaheim, depending on whether each city met the December 2026 deadline.
Cities and counties. Local planning staff must review and update their ADU ordinances before the deadline or risk losing local control over ADU standards for an unknown period of time.
What You Should Do Now
Here are practical steps to take before the January 1, 2027 deadline:
- Check your city’s current ADU ordinance status. Contact your local planning or building department and ask whether the city has adopted an updated ordinance to comply with AB 956 and SB 1117.
- Review any pending permit applications. If you already submitted an ADU application, ask how the city will handle it if the local ordinance becomes void on January 1, 2027.
- Hold off on finalizing plans based on old local rules. Setback, height, and size limits may change. Confirm current standards before you pay for final architectural drawings.
- Keep written records. Save copies of emails, permit submissions, and city correspondence in case questions come up about which rules applied on a given date.
- Talk with a real estate attorney before you sign contracts. A lawyer can help you understand which standards apply to your specific lot and zoning district during this transition period.
How TEZ Law Firm Can Help
TEZ Law Firm’s real estate and construction practice can review your ADU plans against current state and local requirements and help you understand how a void or updated ordinance may affect your project in Los Angeles, Orange, San Bernardino, or Riverside County. The firm can also assist property owners and landlords who face disputes with a city, a neighbor, or a tenant connected to an ADU project through its business litigation and landlord-tenant practice. Attorneys can review permit denials, lease terms for ADU rentals, and correspondence with local planning departments.
Frequently Asked Questions
What happens if my city does not update its ADU ordinance by December 31, 2026?
Under AB 956 and SB 1117, a city or county ADU ordinance that does not match the new state standards becomes null and void as of January 1, 2027. This generally means the city cannot enforce its old local ADU rules, and state default standards may apply to new applications until the city adopts a compliant ordinance.
Does this law affect every neighborhood, or only certain zoning districts?
AB 956 and SB 1117 expand ADU protections to every zoning district that allows single-family homes. This is broader than earlier ADU laws, which did not always cover every residential zone.
I already have an ADU permit application pending with my city. Will this change affect me?
It may. If your city’s ordinance becomes void on January 1, 2027, the standards used to review your application could change. You should ask your city’s planning department directly how it plans to handle pending applications during the transition.
Can a void local ordinance make it easier to build an ADU?
In some cases, yes. A void ordinance can remove local restrictions that were stricter than state law. However, the transition can also create uncertainty, so it is worth confirming current rules with the city and with an attorney before moving forward.
Where can I read the actual text of AB 956 and SB 1117?
Both bills are available on the California Legislative Information website at leginfo.legislature.ca.gov. You can search by bill number to review the full text, legislative history, and signing date of September 29, 2026.
If you own property in West Covina, Los Angeles, Anaheim, San Bernardino, Riverside, Ontario, Pomona, or elsewhere in Southern California and you have questions about how these new ADU rules may affect your plans, you can contact TEZ Law Firm to schedule a consultation. Managing attorney JJ Zhang (California Bar #326666) leads the firm’s offices in West Covina, City of Industry, and Newport Beach. You can reach out through the firm’s contact page to discuss your property and timeline before the January 1, 2027 deadline arrives.
This article is general information, not legal advice, and reading it does not create an attorney-client relationship. Laws and agency practices change; contact TEZ Law Firm (West Covina, California) at 626-888-6856 or [email protected] about your situation. Prior results do not guarantee a similar outcome.