Accessory Dwelling Units

The ADU Center of Napa and Sonoma County provides homeowners who are interested in accessory dwelling units (ADUs) with tools and resources including an ADU Workbook, ADU Calculator, and spotlights of Napa and Sonoma County homeowners who have built ADUs.

The City of Napa is excited to partner with Napa Sonoma ADU and other jurisdictions around Napa and Sonoma counties to support residents in planning for and building ADUs. The Napa Sonoma ADU Standard Plans Program provides property owners with easy access to dozens of “off the shelf” ADU plans that can be purchased at low cost, saving thousands of dollars and months of time over a custom design. 

Plan options include site-built and prefabricated designs of various sizes, including “pre-reviewed” plans. The City of Napa Building Department accepts “pre-reviewed” ADU plans as part of an ADU permit application. When using the Napa Sonoma ADU Standard Plans gallery you can select our jurisdiction to see the plans that we consider to be pre-reviewed

Check out the pre-reviewed plans (by an outside agency for completeness) Napa Sonoma ADU Plans Gallery

Keep in mind that these plans have been pre-reviewed for completeness for submittal but still need to be fully reviewed by all City of Napa staff for compliance to the Building Codes and standards prior to approval and issuance of a building permit.

  1. Permit Techs

    General Email

  2. Vincent Caballero

    Building Inspector

  3. Terri Ritchie

    Permit Technician

  4. Taylor Tobler

    Building Inspector

  5. Jason Williams

    Chief Building Official

  6. Trevor Slevin

    Building Plans Examiner

  7. Stephen Dudla

    Building Inspector

  8. Jackson Willoughby

    Building Inspector

  9. Inspection Line

    Phone: 707-257-1063 (Automated)