Where

ADU rules by location

ADU law is a state floor with local rules on top. This page is honest about which jurisdictions we have actually recorded, which today is none: a city page ships only once that jurisdiction’s own code supplies every field we require, down to the fee schedule and the last-reviewed date.

Coverage today

jurisdiction records published

A city page ships here only once that jurisdiction’s own code supplies every field we require. Until then this page says so.

The alternative, generating a page per city from the California state minimums with the city name substituted, would produce hundreds of URLs that look local and are not. That is the single most common pattern in ADU search results, and it is the reason this site exists.

California statewide rules are covered in ADU regulations; city-level evidence is in the research below.

What a city page must carry

Maximum size
Setbacks
Height
Parking
Owner-occupancy
Permit path
Fee schedule
Effective date
Official source
Last-reviewed date

Permit data

Where we hold ADU permit data

Five California jurisdictions publish permit records detailed enough to show who builds ADUs there and how long approval takes.

Los Angeles1,995 contractors named on 3,782 ADU sites. Median 162 days from submission to an issued permit.Read the research →San Francisco783 contractors named on 1,296 ADU sites. Median 445 days from filing to an issued permit.Read the research →Sacramento353 contractors named on 736 ADU sites. The ten most active firms appear on 28% of them.Read the research →San José316 contractors named on 461 ADU sites. 81% of them appear on a single site only.Read the research →Marin (unincorporated)221 contractors named on 276 ADU sites. Median 174.5 days from receipt to an issued permit.Read the research → Your city is not here?Your planning department is the authority for your parcel. If you hold a sourced record for your jurisdiction, send it to us.Contact us →

Counts are named-contractor records from permit extracts harvested 29–30 August 2026; a firm named in two cities is counted in both.

City-level research

What we do have, at city level

Several research pages already carry genuinely local, sourced detail. Look there while the structured records are built.

Every California city’s ADU rules: the trackerThe widest local coverage we hold.ADU fees by city: the 750 square foot cliffCity fee schedules, sourced.How long an ADU takes to approve, by cityMeasured from permit records.Which California cities publish pre-approved ADU plansPlan catalogs, city by city.Where California cities publish permit dataThe primary sources themselves.

Outside California

The rest of the country

Our corpus is heavily Californian and we do not pretend otherwise. Start with the two studies here, then go to your own jurisdiction’s planning department, which is the only authority that can answer for your parcel in any state.

If you have a sourced jurisdiction record you think we should publish, or you spot an error in one of the research pages, send it to us.

Which states have actually legalized ADUsThe state-law picture. ADU growth outside CaliforniaDo the new laws work?

The one thing to take from this page

A state rule is a floor, not your answer.

Even where California guarantees you an 800 square foot unit with four-foot setbacks, your city may permit considerably more. On everything the state has not occupied, it may require considerably more of you. Check the local record before you design anything.

Questions

Questions people ask

Do ADU rules vary by city?

Substantially. In California a state floor applies everywhere, but size limits above that floor, design standards, fees, and the permit path itself are set locally. A rule quoted without its jurisdiction cannot be relied on.

Why do you not have a page for my city?

Because we have not yet recorded that jurisdiction’s own code against our own standard. We would rather say that than publish a page that is the state default with your city’s name on it, which is what most city ADU pages online actually are.