ADU Rules: El Cerrito vs Walnut Creek
How do adu rules rules compare between El Cerrito, CA and Walnut Creek, CA?
El Cerrito and Walnut Creek 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 →Walnut Creek, CA
Contra Costa County
Walnut Creek must allow Accessory Dwelling Units (ADUs) and Junior ADUs on all residential lots under California Government Code Section 65852.2, as strengthened by AB 68, AB 881, and SB 13. Permitted detached ADUs up to 800 sq ft require 4-foot side/rear setbacks, no replacement parking within half-mile of transit, and 60-day permit processing.
View full Walnut Creek rules →Key Facts Comparison
| Fact | El Cerrito | Walnut Creek |
|---|---|---|
| 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) | - |
| Processing time | 60 days ministerial | - |
| Short-term rental | Prohibited for ADUs (<30 days) | - |
| - | - |
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.
Walnut Creek FAQ
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