ADU Rules: El Cerrito vs San Ramon
How do adu rules rules compare between El Cerrito, CA and San Ramon, CA?
El Cerrito and San Ramon have similar restriction levels.
El Cerrito, CA
Contra Costa County
Contra Costa County allows one ADU and one JADU on any residential lot by ministerial permit, consistent with AB 68/AB 881 and Gov. Code 65852.2. Detached ADUs up to 800 sq ft with 4-foot setbacks are permitted as of right, with 60-day review, no impact fees under 750 sq ft, and no replacement parking required near transit.
View full El Cerrito rules →San Ramon, CA
Contra Costa County
ADUs allowed per CA Gov Code §65852.2 and San Ramon Zoning Ordinance §D4-39. One detached ADU and one JADU per single-family lot. Setbacks: 4 ft side/rear, 20 ft front for detached units. JADU up to 500 sq ft within existing home. Permit review: 6–12 weeks. Pre-approved plans available through Permit Ready ADU program.
View full San Ramon rules →Key Facts Comparison
| Fact | El Cerrito | San Ramon |
|---|---|---|
| Units allowed | 1 ADU + 1 JADU per lot | - |
| Max detached ADU size | 800 sq ft ministerial; up to 1,200 sq ft | - |
| Setbacks | 4 ft side/rear (state minimum) | 4 ft side/rear, 20 ft front |
| Processing time | 60 days ministerial | - |
| Short-term rental | Prohibited for ADUs (<30 days) | - |
| Detached Max | - | 1,200 sq ft |
| JADU Max | - | 500 sq ft |
| Rebate | - | Up to $7,500 (ADU Accelerator) |
Highlighted rows indicate differences between cities.
El Cerrito FAQ
Do I need to provide a parking space for my new ADU?
No, if your property is within half a mile of public transit, in a historic district, or the ADU is a conversion of an existing garage. Otherwise one space is required, which can be in a driveway tandem.
Can I rent my ADU on Airbnb?
No. State law allows counties to prohibit ADU rentals under 30 days, and Contra Costa prohibits short-term rentals of ADUs.
San Ramon FAQ
Can I build an ADU on my property in San Ramon?
ADUs allowed per CA Gov Code §65852.2 and San Ramon Zoning Ordinance §D4-39. One detached ADU and one JADU per single-family lot. Setbacks: 4 ft side/rear, 20 ft front for detached units. JADU up to 500 sq ft within existing home. Permit review: 6–12 weeks. Pre-approved plans available through...
What are the size limits for an accessory dwelling unit in San Ramon?
Detached Max: 1,200 sq ft. JADU Max: 500 sq ft. Setbacks: 4 ft side/rear, 20 ft front. Rebate: Up to $7,500 (ADU Accelerator).
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