Detached and attached ADUs in Berkeley, CA
A new unit on your lot is the biggest ADU project, and the city limits depend on where the lot sits. A licensed contractor scopes the project and writes the contract.
What Berkeley sets for a new ADU
The city's ADU information sheet lists the limits for new construction. Outside the Hillside Overlay, an ADU can be up to 1,200 square feet. Inside the Hillside Overlay, the limit is 850 square feet for a studio or one bedroom and 1,000 square feet for two or more bedrooms. A new detached ADU can be up to 25 feet tall outside the overlay and 20 feet inside it. Rear and side setbacks are a minimum of 4 feet, and parking is not required.
How many ADUs a lot can have depends on the building type and on whether the lot is in the Hillside Overlay, and the city's information sheet has the table. Up to 800 square feet is left out of the lot coverage and floor area calculations. Whether your lot qualifies for any of this is for the contractor and the city to confirm.
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What comes with the permit
Every ADU needs a building permit. The city charges a $250 zoning plan check fee and a $500 neighbor noticing fee at submittal, and it mails the courtesy notice to neighboring owners and tenants within 10 working days. A new ADU also needs a recorded deed restriction and a new address assignment. The city says new ADUs are subject to its Electrification Reach Code. The full steps are in the permit guide.
New ADU questions
Do I have to live on the property?
For a regular ADU, the city says the owner does not have to live on site. A junior ADU that shares a bathroom with the main home does carry an owner-occupancy requirement.
Can I rent the ADU short term?
The city says no. The deed restriction recorded before the building permit is issued bars use of the ADU as a short-term rental.
Ask a licensed ADU contractor to follow up
Send a request with your address and whether you are thinking of a detached unit, a garage conversion, or a junior ADU. We pass your request to one independent licensed contractor who serves Berkeley, CA, if one is available.
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