Welcome to the Napa Sonoma ADU
Standard Plans Program
This webpage is hosted by the nonprofit Napa Sonoma ADU Center, working in collaboration with jurisdictions across Napa and Sonoma counties. Browse the gallery of ADU designs to find the one that works best for you.
What is Napa Sonoma ADU? What does it mean to be “pre-reviewed”? Which jurisdictions are participating? See answers to these and more frequently asked questions.
How this works
Determine What’s Possible
Get help from the Napa Sonoma ADU Center with:
- ADU feasibility consult
- Help understanding costs, financing options, and return on investment
- Info on your local ADU rules & permit process
Takes you to the Napa Sonoma ADU Center website
Pick Your Plan
Filter the gallery of plans to find which ones you like.
Contact Your Designer
Use the contact information on your chosen plan to get in touch with the designer, license the plan, and learn next steps.
From Plan to Permit
Contact your jurisdiction’s building department and develop your full ADU permit application.
How this works
See the site in action and learn how it can help you get started on your ADU project.
IMPORTANT: Make sure to start with the Pre-Work to ensure the plan you select will be accepted by your jurisdiction. Also, remember that even “pre-reviewed” plans must be submitted along with additional information for final review and approval by your jurisdiction’s building department. Carefully review your jurisdiction’s submittal requirements. We highly recommend engaging the designer/architect or a contracting professional to help you through the permitting process.
ADU Plans Gallery
Find Your Plan
If you’re looking for “pre-reviewed” plans, start by choosing a jurisdiction, then continue filtering below. Skip to the filters below to search all plans.
Use the options below to filter for plans that fit your goals and preferences. Note: Not all plans in this gallery will necessarily work for your property or jurisdiction.
Site-built: Traditional Traditional on-site construction
Site-built: Panelized Framing packages, wall-systems, SIPs. These are ‘partially constructed’ off-site and assembled on-site.
Prefabricated: State-certified Modular housing, built in a factory and certified by HCD. Built to California building codes.
Prefabricated: Federally-certified Manufactured housing, built in a factory and certified by HUD. Built to Federal building codes.
All electric All the appliances and HVAC are electric instead of natural gas.
Solar-ready The design and electrical system could easily have a solar system added to the ADU.
Energy-efficient A range of strategies to minimize the energy consumption, such as LED lighting, efficient HVAC systems, and well-insulated walls and ceilings.
Net zero A net-zero building will generate as much energy as it consumes in a year, typically via solar panels.
Indoor/outdoor living A design that provides outdoor amenities such as a patio or deck.
Universal design elements A design that includes features and details that make it accessible and functional to all people regardless of age, disability, or other factors.
Accessible Similar to Universal Design Elements, but more extensive, including no-threshold shower, wheelchair turnaround space in the bathroom, etc.
In-unit washer/dryer An ADU with a dedicated space and hookups for a washer and dryer.
Fire-resistive construction (Ch. 7A Compliant) A design suitable for areas, such as the wildland-urban interface (WUI), or other areas of high wildfire danger.
Turn-key ADU This is a ‘turn-key’ solution. The company handles all the permitting, site work, building, and inspection of the ADU project from start to finish.