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Permit guides

ADU Permits in Alameda: a Homeowner's Guide

What you can build, which permits you need, and how the review actually works — in plain language.

Last updated October 2026. Rules change; always confirm current requirements with the city or county before you build.

Who handles your permit

The City of Alameda Planning, Building, and Transportation Department — the Permit Center is at 2263 Santa Clara Ave., Rm. 190, Alameda, CA 94501 (510.747.6800, permits@alamedaca.gov), open Monday–Thursday 8:30–12:30 and 1:30–3:30, closed Fridays. Applications go through Accela Citizen Access: Planning reviews the design against zoning (size, height, location, setbacks), and Building reviews the plans against the California Building Code. The city notifies you with a "Hold Notice" if corrections are needed, or when the permit is ready.

What you can build

Alameda's ADU rules are in Section 30-5.18 of the municipal code, updated by the City Council in September 2026:

On a single-family lot you can now have one attached ADU, one JADU, and one detached ADU of up to 800 square feet. No neighborhood notification is required — review is ministerial by state law. ADUs must be rented for 30 days or more; no short-term rentals like Airbnb.

Alameda: check for historic designation first

Alameda has a large stock of designated historic resources and landmark-quality older homes, and this is the city's distinctive wrinkle. If your property is a designated historic resource, a Certificate of Approval — a discretionary review that includes neighbor notification — must be approved by the Planning Division before you apply for the ADU building permit. The city's guidance is that ADU designs on historic properties should be contemporary and compatible rather than imitating the historic architecture. Separately, Alameda opted into AB 1033 in 2026, so qualifying ADUs can be sold as condominiums — a useful option if you're building to hold and later sell.

What goes into the submittal

• ADU permit application — filed with the Building Division through Accela Citizen Access.
• ADU Zoning Checklist — the city's own checklist, included with the application.
• Plans (11" x 17" minimum) — plot plan and grading plan; architectural plans (roof plan, floor plan, exterior elevations, cross sections); structural plans (roof and floor framing, foundation, structural details); electrical, plumbing, and HVAC plans.
• Calculations — structural calculations (not required if the plans comply with the California Residential Code) and Title 24 energy calculations.
• Recorded Declaration of Restrictions — recorded at the Alameda County Recorder's office.
• Certificate of Approval first — if the property is a designated historic resource, that approval precedes the ADU building permit application.

Where applications usually get stuck

• Historic designation discovered late. The Certificate of Approval is its own process with its own timeline — don't design around it retroactively.
• Correction rounds. Each plan-check round runs about 30 days; thin submittals with missing structural details or energy forms multiply the cycles.
• Utility connections. New or separate connections for an ADU may mean permits or fees with the service providers — check with planning staff early.
• Protected trees. Tree removal or relocation needs its own permit before the building permit issues.
• HOA rules. Homeowner associations can't block an ADU, but they may still have design guidelines to work through.