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Sonoma County Board of Supervisors Adopts Updated Accessory Dwelling Unit Ordinance

Published:  September 22, 2021

On September 14, 2021, the Board of Supervisors adopted updated local regulations governing Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs). The new ordinance will take effect October 14, 2021. 

The State legislature enacted changes to ADU and JADU laws, effective January 1, 2020, which reduced local zoning barriers to Accessory Dwelling Unit development in response to the housing affordability crisis. The changes nullified the County’s ADU and JADU regulations. Since the changes took effect, Permit Sonoma has been reviewing and processing permits for ADUs and JADUs using only the standards in State law.

The new ADU and JADU regulations bring County regulations into compliance with State law, allow the County to continue to implement certain provisions of its existing ADU regulations, and streamline the permitting process. 

The new ordinance replaces Zoning Code Section 26-88-060, Accessory dwelling units, and Section 26-88-061, Junior accessory dwelling units, and amended relevant definitions in Article 4 (Glossary) and Article 24 (Residential Use Standards) and the land use tables in Article 10 (Commercial Zones) and Article 12 (Industrial Zones)

Download adopted ordinance (Ordinance No. 6352)

Review materials from the September 14, 2021 meeting

Watch the proceedings from the September 14, 2021 meeting

More information about ADUs and JADUs

Contact Information

Contact Planning by Phone
Monday – Friday
10:00 AM – 12:00 PM
1:00 PM – 3:00 PM
2550 Ventura Avenue
Santa Rosa, CA 95403
38.465074, -122.723705


Accessory Dwelling Unit Regulations

Accessory Dwelling Unit Calculator
The ADU Calculator is a resource to help estimate the costs, returns, and benefits associated with building an ADU

ADU Rescue Program
Learn more on how you may qualify and apply for an ADU or JADU enforcement violation extension.

Napa Sonoma ADU Center
The Napa Sonoma ADU Center provides resources for homeowners in Napa and Sonoma counties who want to build an ADU.

Fire Prevention & ADUs

Fire Prevention Information on Accessory Dwelling Units

Fire Prevention and HazMat

Requirements for ADUs including fire access, sprinklers, and more.

Sonoma County Housing Authority

Resources for Property Owners

Hands forming house

If you plan to rent your ADU, consider participating in the Housing Authority's Housing Choice Voucher program and being a part of the solution to the County's affordable housing crisis.

State ADU Law

California Department of Housing and Community Development's web site describing state laws and regulations about Accessory Dwelling Units.

View State Web Site