Disclaimer

General information only

Summaries of California ADU law (Government Code §§66313–66342 and related sections), city and County programs, utility requirements and property tax rules are provided for general information. They are not legal advice. Read the linked sources and confirm requirements with the city, the County, Central San and your water provider before you design or build.

Costs

Cost figures are published by contractors and manufacturers (labeled on each page) and are broad ranges. Actual quotes depend on your lot, design and finishes and can be below or above the ranges shown.

Incentives

Rebate, grant and fee-reduction status is dated (October 2026) and can change without notice. Nothing here guarantees eligibility or funding.

Tax and lending

Property tax and financing information is general and not tax or lending advice. Consult a tax professional and a lender.

No affiliation

We are not affiliated with any government agency, utility district or ADU manufacturer. Names are used only to identify sources and programs.

Referral disclosure

Walnut Creek ADU Builders is an independent website that connects homeowners with local ADU contractors. We are not a contractor; contractors may pay us for project requests. Verify any license at cslb.ca.gov.