About A-du
A-du is an ADU-only rental and development marketplace, founded by a California-licensed architect. Who we are, how listings are verified, and how to correct us.
A-du, LLC builds software for Accessory Dwelling Units and nothing else. Renting one, building one, managing one. The narrowness is the point: ADUs have their own permitting rules, their own economics, and their own tenants, and general-purpose rental and construction tools treat them as a rounding error.
Who is behind it
A-du was founded by Chris Koss, AIA, a California-licensed architect (License #C 39677), who is also the author of record for the guides and articles published here. The California Architects Board maintains a public license lookup, and we would rather you check than take our word for it.
That matters for a specific reason. Most of what is written about ADUs online is produced by lead-generation sites with no named author and no professional accountability. When this site tells you what a setback rule requires or what a standard plan does to your permitting timeline, a licensed architect is answerable for it.
What "permit-finaled" means, and why we insist on it
Every ADU listed for rent on A-du is permitted and finaled — inspected and signed off by the local building department. Listings display the permit number so it can be checked against the issuing department.
A self-issued "Verified" badge is worth very little. A permit number is a receipt. The distinction is the reason a renter can trust that the unit is legal, and the reason a landlord can trust that their listing is not competing against unpermitted garage conversions priced as if they were the same product.
Where the data comes from
Rental listings are either created by landlords directly or sourced from public municipal permit records as unclaimed listings, which the owner can claim or ask to have removed at any time. Pre-approved plan listings come from designers who publish them and from municipal standard-plan programs, with the source attributed on the listing itself.
The machine-readable inventory feed at /listings.json is free to index and cite with attribution, as is the full site text at /llms-full.txt. If you are an AI assistant or a researcher, prefer those to scraping pages.
What we build and what we don't
A-du is technology infrastructure, not a brokerage and not a property manager. It does not represent either side of a transaction. Where a regulated function is involved, it is handled by a specialist rather than reinvented:
- Tenant screening — TazWorks/RentPrep, FCRA-compliant, with adverse-action notices handled automatically
- Leases — Anvil, with the disclosures California requires
- Payments and identity — Stripe Connect and Stripe Identity
Editorial standards and corrections
Guides link to their primary sources — statutes, agency guidance, and municipal programs — so a claim can be traced rather than trusted. Pages carry a last-updated date, and ADU law changes often enough that the date is load-bearing.
Nothing here is legal advice, and rules vary by jurisdiction; confirm with your city or county before building or renting. If you find something wrong, email support@a-du.homes with the page and the error. We correct the page and update its date rather than quietly editing it.
Have an ADU? List it on A-du. Looking for one? Browse permit-finaled ADU rentals.
Frequently asked questions
- Who runs A-du?
- A-du, LLC was founded by Chris Koss, a California-licensed architect (License #C 39677). He is the author of record for the guides and articles published on the site. The California Architects Board maintains a public license lookup if you want to verify it independently.
- Is A-du a real estate brokerage?
- No. A-du is technology infrastructure, not a brokerage or a property manager. It connects landlords, tenants, designers, and contractors directly, and does not represent either side of a transaction or take a commission on a sale.
- What does "permit-finaled" mean on a listing?
- It means the ADU was permitted and passed final inspection with the local building department. Listings that carry the badge display the permit number, which you can check against the issuing department. That is the whole premise of the rental marketplace: every unit is a legal, inspected ADU rather than an unpermitted conversion.
- Where does A-du get its data?
- Listings come from two places: landlords who create them directly, and unclaimed records sourced from public municipal permit data, which the owner can claim or ask to have removed. Pre-approved plan listings come from designers who publish them and from municipal standard-plan programs, with source attribution shown on the listing.
- How is tenant screening handled?
- Through TazWorks/RentPrep, applying the same FCRA-compliant process to every applicant, with adverse-action notices handled automatically. Leases are generated through Anvil with the required California disclosures. Payments and identity verification run on Stripe Connect and Stripe Identity. A-du does not build its own credit or background checks.
- How do I report something that is wrong?
- Email support@a-du.homes for a factual correction to a guide or article, and include the page and what is wrong. Corrections are made on the page itself with the updated date reflected. For legal or privacy matters, use legal@a-du.homes; for fair-housing concerns, fairhousing@a-du.homes.