How we rank builders
Every point comes from something you can check yourself: the state license board and the builder's own website. Nobody can pay to move up. Last full check: Oct 18, 2026.
Who gets ranked
A company is ranked only if it builds ADUs for Bay Area homeowners and holds an active California contractor license (its own, or a licensed partner it names). Companies with an expired or suspended license, design-only firms, marketplaces and firms outside the Bay Area keep a profile that says what we found, but they aren't ranked. Today 24 builders pass.
The score
| Part | Points | How it's scored |
|---|---|---|
| CSLB license | 30 | 30 if the license is active, class B, and the number on the builder’s own site matches CSLB. 25 if we matched it by name, phone or address instead. 20 if CSLB shows pending disciplinary action, or the work is done by a disclosed licensed partner. 10 if active but not class B. |
| Years licensed | 15 | From the original CSLB issue date: 15 years or more 15, 10 to 15 years 12, 5 to 10 years 9, 2 to 5 years 5, under 2 years 2. |
| ADU types shown on own site | 15 | 3 points each for detached, attached, garage conversion, junior ADU, and prefab or a ready-made plan library, only if the builder’s own site shows it. |
| Cities it names (of the 18 we cover) | 15 | How many of our cities the builder names on its own service-area page: 10 or more 15, 5 to 9 10, 1 to 4 5. |
| Local office | 10 | Where the builder works from, by its own site or its CSLB address. On a city page: 10 if the office is in the same county, 5 if elsewhere in the nine-county Bay Area, 0 if outside. On the Bay Area list: 10 for any Bay Area office. A builder based outside the Bay Area can still rank, and its card says where it is based. |
| Published prices | 10 | 10 for its own dollar prices on its site. 5 for general market ranges only. 0 for none. |
| Public reviews (not scored yet) | 15 | Planned: 15 for a 4.7 rating or better on a platform with at least 10 reviews, 12 for 4.5, 8 for 4.0. Not scored yet. Google, Yelp and Houzz block automated checks, and we won’t copy ratings we can’t verify, so every builder gets 0 here for now. |
Ties go alphabetical. A young license scores low on years, which says nothing about the quality of the work. On a city page we list only builders whose own site names that city.
Sponsored and Partner labels
- Sponsored means a builder paid for a spot. Sponsored spots sit in their own labelled box and never change the ranked list. The builder keeps its own earned place in the list too.
- Partner means requests from this site go to that builder. We show the label only on pages where that is true.
- When the people who run this site have a business relationship with a ranked builder, its profile says so.
Rules and fees
City rules and fees come from each city's ADU pages, fee schedules and fee estimators, school district fee notices, and utility rate schedules. Every number links to its source with the date we read it. When a city site blocked our checker and we read an archived copy of the same official page, the source list says so. When a city doesn't publish a number, we say that instead of guessing.
Build cost estimates
No one has surveyed Bay Area ADU build costs since UC Berkeley's 2021 owner survey. We raise that survey's numbers with California's construction cost index and check them against builders' published prices. Our estimate is always labelled as ours and kept apart from official fees.
Corrections
If a fact about your company or city is wrong, use the "Send a correction" link on the builder profile. We check every correction against CSLB and your own site before changing anything.