Your ADU rights in California

California law requires cities and counties to approve ADUs through a ministerial process. That means the review is a checklist against objective standards: no public hearing, no discretionary design review, no neighborhood notification period where objections can stall your project.

If your application meets the standards, the agency's job is to approve it. Opinions, including your neighbors' opinions, are not part of the process.

Since January 1, 2026, the permitting agency must determine whether your ADU application is complete and give you written notice within 15 business days of receiving it.

If it is incomplete, the agency must list every missing item and how to fix each one. When you resubmit, the agency may only review the items it already flagged. It cannot invent new objections on round two.

If the agency misses the 15 business day deadline entirely, the law deems your application complete, and the 60 day approval clock below starts anyway.

For a lot that already has a single-family or multifamily home on it, the permitting agency must approve or deny a completed ADU application within 60 days.

The statute's own words: if the local agency has not approved or denied the completed application within 60 days, the application shall be deemed approved.

Practical move: keep dated copies of everything you submit and every notice you receive. The clocks in this law only protect you if you can show when they started.

California's architecture licensing law contains an explicit exemption: any person may prepare plans for single-family dwellings of wood-frame construction up to two stories, and for structures appurtenant to them. Most ADUs fit inside that exemption.

This is why qualified ADU designers who are not licensed architects legally exist, and they often charge less. Hiring an architect can still be the right call for a complex or hillside project. The point is that it is a choice, not a legal requirement.

Two real limits: your plans will still typically need a licensed engineer for the structural sheets, and the exemption can fall away if the design departs from conventional wood framing or if the building official determines the project warrants a licensed professional.

On a California home improvement contract, the law caps the down payment at one thousand dollars or 10 percent of the contract price, whichever amount is less. On a $200,000 ADU contract written as a home improvement contract, that is a maximum of $1,000 up front, not $20,000.

A contractor asking for 30 percent down is asking you to ignore a consumer protection law that exists because of how often large deposits disappeared.

If a home improvement contract calls for payments before the job is done, the law requires a written schedule of payments in dollars and cents, tied to specific amounts of work, materials, or equipment.

The working rule: money follows work. Except for that capped down payment, you should not be paying for work that has not been performed or materials that have not been delivered. A payment schedule that front-loads cash ahead of progress is a red flag you can point to in the statute.

The Contractors State License Board publishes license status, classification, bond information, and disciplinary history for every licensed contractor in California. The lookup is free and takes about two minutes.

For a ground-up ADU build, you are generally looking for a B General Building classification. If a search turns up nothing, or shows expired or revoked, that is a hard stop, not a negotiation.

The City of Los Angeles runs a Standard Plan Program: ADU designs by licensed architects that LADBS has already reviewed and pre-approved, so plan check shrinks to site-specific review. Most plans are licensed from the architect who owns them for a fee. One plan, YOU-ADU, is owned by the city and free for property owners to use.

LA County runs a parallel program for unincorporated areas with three county-owned plans, from an 800 square foot one-bedroom to 1,200 square foot two and three bedroom layouts, free to download. County plans must be permitted exactly as designed, though floor plans may be mirrored.

Which program applies depends on your address. Los Angeles city parcels go through LADBS; unincorporated county pockets go through County Public Works; cities like Burbank, Glendale, and San Fernando run their own processes.