- California State Fire Marshal (PDF) — Information bulletin regarding sprinkler system requirements.
- California Energy Commission updates for ADU - Blueprint Newsletter Issue 129 January 2020 – March (PDF) — ADUs and adoption of 2019 Energy Code: PV (solar panel) Requirements for ADUs
- HCD Information Bulletin — Provides clarification and outlining provisions of various residential types, ranging from recreation vehicles and manufactured homes to site-constructed California
- ADU guidance memo for planning directors in coastal cities and counties (PDF) — January 21, 2022
Guidance from ADU Handbook contributors
You'll find additional resources at the following websites, which are hosted by partners who contributed to HCD's Technical Assistance Booklet.
- Casita Coalition — ADU Best Practices Guidebook
- Casita Coalition — The statewide cross-sector nonprofit offers free downloads of ADU guidance memos for practitioners and homeowners on their Guidebooks and Resources page [casitacoalition.org], including guidebooks on Legalizing an Unpermitted ADU, SB 9 Two-Unit Developments and Lot Splits, Multifamily ADUs, ADU Best Practices, ADU Financing, and Garage Conversions.
Materials from Cities and Counties
- Napa Sonoma ADU
- San Mateo ADU
- Clovis Old Town Cottage Home Program (PDF)
- Del Mar Sample ADU Floor Plans
- Stockton ADU Studio
- Stockton ADU 1 Bedrooms
- Stockton ADU 2 Bedrooms
- Pre-approved ADU plans, and a “Guide to Building Accessory dwelling Units” from the City of Stockton
- “ADU Educational Workshop” — Virtual ADU educational workshops, including planning, permitting, building, financing and property management
- ADU amnesty program - San Mateo County
- ADU possibilities on your lot
- ADU Resource Center the American Institute of Architects (AIA)
- The ABCs of ADUs (PDF)
- Clovis Cottage Home Program (PDF)
- Accessory Dwellings — One-stop resource about accessory dwelling units. (Portland, OR)
- Everything About Building ADU in Los Angeles
- Second Unit Resources Center
- Ideas, Stories, and Photos
- How to Build an ADU — A step-by-step guide from design to move-in
- Second Unit Calculator — Calculate typical costs, rents, and more
- Idea Book (PDF)
- Workbook (PDF)