Sonoma County, CA Zoning Overlays & Bonuses: Density Bonus Law (2026)
Key Facts
- Max bonus
- 50% above General Plan density
- Minimum project size
- 5 base units
- Program limit
- One density bonus program per project
- Application timing
- Filed with discretionary permit application
- Coverage
- Unincorporated county only
Summary
Sonoma County's supplemental density bonus program lets residential projects of five or more units build up to 50 percent above the General Plan and zoning density limit when a set share of units go to extremely low-, very low-, low-income senior, or moderate-income households.
a residential project of five or more base units shall be eligible for a density bonus of up to 50 percent above the maximum density allowed by the General Plan and zone district, if the project provides a total of: 10 percent or more of the base units for extremely low-income households; 20 percent or more of the base units for very low-income households; ... or 40 percent or more of the base units for low-income households
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 64 Update 2).
Full Breakdown
Under County Code § 26-89-050, a residential project of five or more base units in unincorporated Sonoma County can earn a density bonus of up to 50 percent above the General Plan and zone district maximum by dedicating a share of units to extremely low-, very low-, low-income senior, low-income disabled, large-family, or moderate-income households. The county supplemental program runs alongside the separate state density bonus law under Government Code Section 65915, and an applicant may use only one program per project. The bonus is granted only as part of a discretionary permit, such as a tentative map, parcel map, conditional use permit, or design review, and never applies to General Plan or zoning map amendments.
Violations & Fines
Projects that skip the required density bonus application, filed with Permit Sonoma before or with the discretionary permit, forfeit the bonus and must meet standard General Plan and zone density limits instead.
Frequently Asked Questions
Is this the same as the state density bonus law?
Does this apply inside the City of Sonoma or Santa Rosa?
Sources & Official References
Other rules in Sonoma County
California rules heatmap·Compare Sonoma County to another location·View the California zoning overlays & bonuses overview
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