Primary sources first
Every guide starts from the people who make or enforce the rules, not from other websites:
- State law, read on the Legislature's official code site, such as the Government Code sections that govern ADUs.
- California's Department of Housing and Community Development, including its ADU Handbook.
- The Contractors State License Board for license classes, deposit limits and contract rules.
- The City and County of San Diego: the municipal code, information bulletins, fee schedules and permit data.
Builder and vendor pages are used only for prices, because cities don't publish what construction costs. When we use one, we name it in the sentence (“one builder's published prices”) so you know where the number comes from, and we never present a builder's figure as an official fee.
Every number links to its source
Each figure and legal claim in a guide is linked, on the words that make the claim, to the page it came from. Every source is also listed at the end of the guide. If you want to check us, one click takes you to the original.
When we can't verify something
We leave it out. If a statistic, fee or program can't be traced to a source we can link, it doesn't go in the guide, even if it appears on other sites. We would rather a guide be shorter than wrong.
Dates on prices and rules
Prices change and so do laws. Prices carry the date of their source (for example, “as of March 2026”), and each guide shows when it was last updated. When a law has been signed but hasn't taken effect yet, we say when it starts.
Independence
- No builder pays for coverage in a guide or for a mention in one.
- Guides don't contain affiliate links. Links to other sites are plain links.
- We name companies only as cited price sources or as cautionary cases, never as recommendations inside a guide.
How the directory itself earns money, now and later, is on how we make money. How builders are checked and ranked is on how we verify builders.
How we use AI tools
Research and drafting are assisted by AI tools. They help us find and summarize sources and write first drafts. Before a guide is published, its facts are checked against the linked sources, and anything that can't be matched to a source is removed. AI tools don't decide which builders are listed or how they rank; that comes from state license records, city permit data and Google reviews.
Updates
- Monthly: we refresh state license data, Google ratings and reviews, and City of San Diego permit records for every listed builder.
- When laws change: we re-check the guides a new law affects. California's ADU changes that take effect on January 1, 2027 are an example; affected guides are reviewed before and after that date.
- When a source changes: if a price page or rule we cite is updated, we update the guide and its date.
Corrections
If you find an error in a guide or a listing, email hello@findaducontractor.com with the page and what's wrong, plus a source if you have one. We correct verified errors within two business days.
Not legal or financial advice
Our guides are general information about ADUs in California. They aren't legal, tax or financial advice, and rules can vary by city and by lot. Confirm the details for your property with your city or county planning department, and talk to a licensed professional before you sign a contract or take out a loan.