Campbell / Accessory dwelling units
ADU Builder in Campbell
Campbell asks you to pick the building application guide that matches the ADU, then submit it electronically. An express review program the City advertised for ADUs is marked suspended on the Building page. Call R&B at (650) 800-9661. CSLB #1158657.
Two guides, depending on the unit
Campbell’s Building Application Guides (opens in a new tab) separate new construction from interior remodels. The New Single-Family Residential Construction guide (opens in a new tab) is the one the City points to for a new single-family dwelling, including a detached ADU, and for an addition that includes an attached ADU. The Single-Family Residential Remodel guide (opens in a new tab) covers an interior ADU or junior ADU created from existing building area, and it lists garage conversions.
Both guides say applications go through MyGovernmentOnline. The remodel guide tells first-time applicants to create an account before uploading. Building questions on the guide go to the Building Inspection Division at (408) 866-2130 or building@campbellca.gov. Those are City numbers, not R&B’s.
Express Plan Check is marked suspended
Campbell’s Building page (opens in a new tab), in a department update dated August 4, 2025, says the Express Plan Check program for ADUs — described as cutting processing toward one week — has been temporarily suspended. The page tells readers to watch for program updates and mentions a preapproved plan gallery in the meantime.
We will not quote a one-week Campbell ADU review while the City lists that program as suspended. Check the Building page before you plan a schedule around it. A city processing note is not a construction timeline.
Questions homeowners ask
How do I submit a Campbell ADU permit?
Electronically through MyGovernmentOnline, using the City’s Building Application Guide for a new unit or for an interior remodel.
Is Express Plan Check available?
The City Building page has stated that the ADU Express Plan Check program is temporarily suspended. Verify the current notice before relying on it.
Official sources
City rules change. The links below are the pages and documents these notes were checked against. Your address can still differ.
Talk with R&B
R&B Master Construction Inc. · CSLB #1158657. Email info@rbmasterconstruction.com. Headquarters: 84 W Santa Clara St, Suite 700, San Jose, CA 95113. Hours: Monday–Sunday, 7:00 AM–5:00 PM Pacific Time.