Napa Sonoma ADU Center

The bucolic landscapes of Napa and Sonoma counties nurture world-class wines and other agricultural products while attracting many newcomers. High housing demand and limited supply have created housing shortages and high prices that threaten sustainability of the area’s agricultural economy while increasing wildfire risk as urban development has increasingly pushed into the “wildlife urban interface,” or WUI.

As one part of responding to this challenge, the Napa Valley Community Foundation with support from the two counties’ 16 jurisdictions engaged Community Planning Collaborative to help conceptualize, strategize and launch “Napa Sonoma ADU,” an independent nonprofit (fiscally sponsored by the foundation) focused on helping jurisdictions and homeowners create infill housing in the form of new accessory dwelling units, or ADUs.

Napa Sonoma ADU is now widely seen as a statewide best practice, supporting smaller jurisdictions in particular with technical assistance to ensure compliance with state regulations and helping to demystify the ADU development process for homeowners. Most of the tools and resources on the Napa Sonoma ADU website were developed by Community Planning Collaborative, including an ADU calculator which is now being made available statewide thanks to support from the Chan Zuckerberg Initiative, an ADU workbook and process guide, and the recently launched ADU Standards Plans Gallery.

While two phases of work and tool development are now complete, Community Planning Collaborative continues to support the center in achieving their important mission, and we are now replicating similar tools and resources with counties and cities around the state.