Alameda County, California
ADU builder in Alameda County
Alameda County coverage stretches from Oakland and Berkeley's established neighborhoods through southern bayshore communities to the Tri-Valley. Most of these places are incorporated cities with their own ADU permit offices. Castro Valley is an important exception: its unincorporated parcels use the county process.
The county process for unincorporated addresses
For an unincorporated Alameda County property, begin with the Community Development Agency Planning Department for land-use review, and Public Works Building Inspection for the building permit. Oakland, Berkeley, Fremont, Hayward and other incorporated cities handle their own applications.
The county's ADU information page is marked as archived. Use it as a starting reference and confirm current forms and submission steps directly with county staff before relying on an older checklist.
Why one county can contain very different ADU sites
An older bayshore property may have a detached garage and limited side access; a hillside site can put drainage, grading and construction access at the center of the plan. In Pleasanton and Livermore, the relationship between the existing house, backyard and driveway can suggest a different layout again.
For county-permitted properties such as Castro Valley, check the zoning map and ask Planning about the individual parcel. County membership alone does not determine setbacks, design review or utility requirements.
Rules vary by jurisdiction. Call us to confirm what applies to your property.
FAQ
Alameda County ADU questions
Does Alameda County issue Oakland and Fremont ADU permits?
No, not for properties within those city limits. Oakland and Fremont use their own city permit offices. Alameda County handles unincorporated parcels.
Who handles an ADU in Castro Valley?
Castro Valley is unincorporated. County planning and building services are the starting point; confirm the parcel and current application requirements.
Can I use the county's older ADU handout as my final checklist?
Confirm current requirements first. The county's ADU information page is marked as archived, so forms and procedures should be checked with staff.
Free quote
Planning an ADU in Alameda County?
Call us for a quote based on your project.
Call us directly
916.505.2036ADU Design Center2230 26th Street, Sacramento, CA 95818Call to schedule your visit.
Request a free quote
Takes about a minute. We call you back, usually the same business day.