This is the third Housing Update newsletter aimed at keeping Sonoma County residents, developers, service providers, and other interested parties up to date about housing-related news, regulatory changes, opportunities, and incentives.
Housing Policy Changes
ADU Code Update & Resources
“Accessory Dwelling Units (ADUs) are small dwelling units allowed in conjunction with another primary dwelling unit in most residential, mixed-use, or agricultural zones.”
With limited exceptions, a property with a single-family primary residence is entitled to two ADUs and a Junior ADU (subject to specific requirements and standards). Properties with multi-family primary residences may be entitled to more, depending on the quantity of primary units. In recent years, changes to State law have frequently been enacted regarding accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs), with the intent of reducing arbitrary, excessive, or burdensome requirements that unreasonably restrict the creation of this valuable form of housing.
State ADU Law sets parameters for the provisions that local agencies may and may not apply to ADUs and JADUs. Significant changes to State ADU Law took effect at the start of 2025, driving additional implementation and associated code updates. These were adopted on December 9, 2025, with Ordinance No. 6544 and brought the County’s Zoning Code into compliance with new State laws governing ADU and JADUs. Additionally, the updates simplify provisions and provide more flexibility to homeowners in the configurations of accessory units allowed on their properties, further promoting housing development.
The County ADU webpage features informational resources and checklists that will assist homeowners through the ADU permitting process. For questions about ADU permitting, reach out to the Planning Division at [email protected], or visit the Permit Sonoma office to speak with staff directly.
Pre-Reviewed ADU Plans
The County’s ADU Ready program maintains a gallery of pre-reviewed ADU plans. These plans have been reviewed in advance by Building Division staff for compliance with Code requirements, simplifying the design and permitting process, making it faster and more affordable.
Architects and licensed professionals can submit ADU designs to Permit Sonoma for pre-review. Plan-checked designs will be listed in the ADU Design Gallery. Homeowners looking to build an ADU can browse this gallery and contact a listed vendor to obtain a plan package. Plan vendors typically charge fees for using plan sets and may offer a variety of additional services. Applicants can work with a professional or follow owner-builder requirements to integrate the selected ADU plan into a site-specific package for submission with a building permit application.
Once a complete building permit application is submitted and initial fees are paid, the application is reviewed within 30 days for requirements such as zoning consistency, fire code compliance, water supply, wastewater disposal capacity, and other site-specific code requirements. Adjustments to plans may be requested if needed. If all requirements are met, fees are assigned and the permit is issued after payment. Construction can then begin, and after passing inspections and payment of final fees, a certificate of occupancy will be granted.
ADUs and JADUs Without Permits
- If an ADU or JADU was constructed without the benefit of permits, there are reasons to obtain a building permit to legalize the unit.
- ADUs that are unpermitted may unknowingly present health and safety risks to the occupants and pose a significant liability to owners.
- Legalizing the ADU would improve the potential for the rental income and/or resale value.
- Legalization can eliminate any worries about code enforcement actions against you.
Consistent with State Assembly Bill 2533, Permit Sonoma will not deny a permit for an existing unpermitted ADU or JADU that was constructed before January 1, 2020, unless the building is considered substandard pursuant to Health and Safety Code Section 17920.3. Permits will not be contingent on other standards for development, such as setbacks, size, and height restrictions.
“Substandard” means any condition defined by California State Health and Safety Code Section 17920.3, which exists to an extent that it endangers the life, limb, property, safety or welfare of the public, nearby residents, or occupants. The County’s Substandard Conditions Self-Assessment Checklist (coming soon) provides a list of each condition specified in Section 17920.3. More information on this program is available on the County website. ADUs and JADUs constructed after January 1, 2020, may also be legalized but will be required to comply with current building codes.
ADU Rescue is a County program that allows owners of qualifying unpermitted ADUs to ask for an enforcement postponement of up to five years, while the ADU is being brought into compliance. To qualify, the ADU must not be in substandard condition and must have been created within one of the following time periods:
- Before October 14, 2021
- January 1, 2023 – Before January 4, 2024
- January 1, 2025 – Before January 8, 2026
Adoption of Objective Design Standards
“Objective Design Standards (ODS) are a policy effort to streamline housing development approvals by creating fixed, clear, and measurable design standards such as for site design, structure design, and exterior lighting.”
Evolving State requirements continue to limit the authority of local governments to apply discretionary standards to new housing developments, relying instead on objective standards. Objective standards are those that involve no personal or subjective judgment by a public official and are uniformly verifiable and understandable by both the applicant the public official. In addition to meeting State requirements, ODS is anticipated to streamline permitting by providing design certainty, thus creating cost savings and promoting housing development.
ODS for most multi-unit housing development projects, including multifamily and mixed-use, were adopted by the Sonoma County Board of Supervisors in December 2025, fulfilling Subprogram 12b of the Sonoma County General Plan Housing Element. Future efforts may seek to develop ODS tailored to single-family dwellings in Scenic Resource zones to further streamline additional housing development types. Visit the Objective Design Standards webpage for more information.
Agricultural Employee Housing Code Update
Agriculture is an important economic driver in the County, and there is an urgent need for farmworker housing. The County’s Housing Element directs staff to modify Zoning Code to reduce the thresholds needed to qualify for agricultural employee dwelling, and updates to achieve consistency with the California Employee Housing Act.
In 2024, Planning staff conducted outreach with Farm Bureau members, local farmers through the Agricultural Commissioner’s Office, and the local chapter of the Community Alliance with Family Farmers (CAFF). Farmers identified intensive, diversified farming on smaller properties as a growing trend in response to economic uncertainty and rising costs. Because housing remains a significant expense for employers, farmers recommended allowing smaller farms to qualify for agricultural employee housing based on gross annual sales rather than acreage alone. The Board of Supervisors incorporated this feedback into code updates adopted in October 2025.
The approved code revisions also establish a new use category for agricultural employee housing permitted by the California Department of Housing and Community Development (HCD). The HCD housing program allows additional flexibility in the number of dwelling units, and in the type and location of units. Agricultural employee housing permitted through HCD program still requires construction permits issued by the County.
For questions about agricultural employee housing, reach out to the Planning Division at [email protected], or visit the Permit Sonoma office to speak with staff directly.
Housing Resources
Fair Housing Information
The Sonoma County Community Development Commission is pleased to announce that a webpage dedicated to Fair Housing Resources has been added to the Commission’s website. This new webpage provides public information on federal and state fair housing laws and resources available to households seeking legal assistance or information on their housing rights and responsibilities. It also shows participants how the Sonoma County Housing Authority can file a complaint related to fair housing.
County Programs for Saving Water and Energy
The County administers programs and coordinates with partners to provide homeowners with opportunities to save money when making energy- and water-saving improvements to their home. The Sonoma County Energy Independence Program (SCEIP) offers Property Assessed Clean Energy (PACE) financing for permanent energy, water, wildfire safety, and seismic strengthening improvements through the property tax system to multi-family residential and non-residential buildings.
The Bay Area Regional Energy Network (BayREN) is a collaborative of bay area local government partners providing incentives and rebates to qualifying property owners to make energy upgrades to single-family homes, multifamily residential and businesses. Visit the BayREN Program Directory for more information on available energy efficiency rebates.
The Sonoma-Marin Saving Water Partnership was formed to identify and recommend implementation of water efficiency projects and maximize the cost-effectiveness of water efficiency programs in our region. The Partnership represents multiple water utilities in Sonoma County that have joined together to provide regional solutions for water use efficiency. The utilities include the Cities of Santa Rosa, Rohnert Park, Petaluma, Sonoma, Cotati, Cloverdale, and Healdsburg, and Valley of the Moon Water Districts, Town of Windsor, California American Water – Larkfield District and Sonoma Water.
Each of the Partners offer water conservation programs that can assist customers in reducing their water use. Visit the Partnership Program Directory to learn more about rebate opportunities on water efficiency upgrades for your home or business.
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