About California ADU Co.
California-first ADU education and planning guidance, written in plain English for real homeowners.
What California ADU Co. is
California ADU Co. is an educational resource built to help California homeowners and future homeowners understand ADUs, state law, local rules, energy code, and practical planning issues. We're not a contractor. We're not a lender. We're not a sales funnel trying to sell you services. We're an information-first resource.
If you own a house in California and you're wondering whether an ADU makes sense for your property—or if you're trying to understand what your local planning department is asking of you—this site exists to give you clear, accurate answers.
Why this site exists
California's ADU rules involve multiple layers—state law, local ordinances, energy code, permitting. Most homeowners don't know where to start. Information is scattered across government websites, legal texts, and marketing materials from companies trying to sell services.
California ADU Co. exists to organize that information clearly in one place. We pull from official sources, translate dense legal language into plain English, and explain what's required statewide versus what's specific to your city. Whether you're in the Bay Area, Southern California, Central Valley, or anywhere else in the state, you should be able to come here and get honest, reliable information about your options.
How we approach content
Every page on this site is built around these principles:
California-first
Every page focuses specifically on California law, California code, and California cities.
Official sources
Content is built around published guidance from HCD, the California Energy Commission, and local planning departments.
Plain English
Legal and code language is translated into clear, readable explanations.
Statewide vs local
We always separate what state law says from what individual cities may require.
Updated regularly
Law and code pages include last-updated dates and are reviewed when rules change.
What we don't do
It's just as important to be clear about our boundaries:
- We don't sell ADU design or construction services.
- We don't provide legal advice. When in doubt, talk to a lawyer.
- We don't replace your local planning department. Always verify project-specific details with them.
- We don't promise specific outcomes. Rules and timelines vary by jurisdiction.
Editorial standards
We prioritize accuracy by sourcing content from official California agencies—Housing and Community Development (HCD), the California Energy Commission, local planning departments, and published state and local code. We translate legal and code language into plain English so you don't need a law degree to understand your options. Pages covering state law and building code include last-updated dates and are reviewed whenever rules change. And we're transparent about what we don't know—when a question is outside our scope or requires local verification, we say so.
Get in touch
Have a question, feedback, or a suggestion? We'd like to hear from you.
Explore the site
Here are some pages that might be helpful to start with:
This page is for general educational purposes only. California ADU law, city implementation, and code requirements can change. Always verify project-specific requirements with the relevant planning department, building department, and qualified professionals.
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