Napa Valley Napa Sonoma ADU Center launches program to ease building of accessory homes

November 4, 2022 by Edward Booth in the Napa Valley Register

Image of of a recently completed ADU in Napa, California
ADU (2nd residence) on the property of an existing single-family house.


A local Accessory Dwelling Unit Plans Program, intended to ease the process of helping homeowners figure out the design and permitting for the junior housing units, has officially launched. And for those curious to see examples of prefabricated small dwellings, four free tour events are scheduled in the city of Napa this month.

ADUs, commonly known as “granny flats” or “in-law units,” are self-contained second residences that can be attached or detached from single-family homes. Development of the homes has become increasingly popular in the past few years, owing to a series of state laws that greatly eased the approval process at the local government level.

The ADU plans program is part of an effort to make it easier for homeowners to figure out if they want to build a junior unit in the first place. It’s the result of a partnership between the Napa Valley Community Foundation and local cities and counties to create and fund the nonprofit Napa Sonoma ADU Center, which assists those interested in building an accessory home and has helped 550 people begin ADU projects so far, according to a news release from the foundation. At a base level, the program provides an online inventory of more than 50 ADU sets from a variety of companies. About half are “pre-reviewed” by city and county building departments for building code compliance.

The announcement notes that increasing ADU development has been widely recognized as one way to help ease California’s deepening housing shortage, and that the Plans Program is one part of the foundation’s strategy to support the development of second units in Napa and Sonoma counties. Among other efforts, that includes a partnership with Redwood Credit Union early this year to create a construction loan program specifically for ADUs.

“We are focusing on second units because they put the power of solving our housing crisis in the hands of our concerned community members,” said Julia DeNatale, vice president of community impact for the community foundation, in the press release. “ADUs can help bridge the middle-income and workforce housing gap and produce housing more quickly and affordably than many other housing types, with opportunities to expand access to families who cannot afford market-rate rents on freestanding units.”

The ADU tours — slated for Nov. 6, 9, 19 and 30 — will take place at CrossWalk Community Church at 2590 First St. in Napa. Three prefabricated second dwellings, ranging in size from 150 to 740 square feet, will be featured, according to the community foundation. There will be booths with designers, architects and prefab companies that have ADUs included in the Plans Program present at the tour events, along with ADU finance experts, local planning and building officials and staff from the ADU center.

Those interested in attending can RSVP to the events at https://napasonomaadu.org/aduevents.

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