ADU Regulations in Santa Rosa, California
Nestled in Sonoma County, Santa Rosa has been proactive about ADUs since the 2017 wildfires, streamlining permit processes as part of the city's recovery and housing resilience strategy. The Urban Growth Boundary may influence lot coverage for larger properties.
Below is a summary of the key zoning rules applicable to Accessory Dwelling Units in Santa Rosa as of 2026. Regulations are governed by California's AB 68 (2020), AB 881 (2021), and AB 3182 (2024) which together establish a statewide ADU framework.
| Regulation | Requirement |
|---|---|
| Maximum Size | 1,200 sq ft |
| Property Setbacks | 4 ft rear, 4 ft side |
| Extra Parking Required | Not required |
| Owner Occupancy | Not required |
Additional Local Requirements for Santa Rosa
- Height limit: 16-18 ft
- Urban Growth Boundary constraints may apply
- Conversion of existing space encouraged
- Fire sprinklers may be required
📥 Download the Complete Santa Rosa ADU Cheat Sheet
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Can I build an ADU in Santa Rosa?
Santa Rosa has been proactive about ADUs since the 2017 wildfires, streamlining permit processes to encourage more housing.
How big can my ADU be in Santa Rosa?
What is the maximum ADU size allowed in Santa Rosa? ADUs in Santa Rosa can be up to 1,200 square feet, subject to the property's zoning and lot coverage limits. Always confirm the exact allowed size with the Santa Rosa planning department before designing your project.
What about setbacks and other requirements in Santa Rosa?
What are the setback requirements for an ADU in Santa Rosa? ADUs in Santa Rosa generally require setbacks of 4 ft rear, 4 ft side. California state law (AB 68) limits local setback requirements to 4 feet for existing structures, but always verify with local zoning.
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