Alameda County

Berkeley ADU rules

Research summary of local ADU rules on file for Berkeley in Alameda County. Not a determination for a specific lot.

Last checked October 23, 2026.

City or county ADU page

Berkeley rules on file

Local rules recorded in this project for this jurisdiction. Where a city figure on file is stricter than the state baseline on file, both are shown.

Permit route
All ADUs and junior ADUs need a building permit, and zoning compliance is checked during building permit review. Apply in person at the Permit Service Center or through Permits Online.
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Other Requirements: Building Permit, accessed 2026-10-23.

Courtesy notice to neighbors
Within 10 working days of a new ADU building permit application, City staff mail a courtesy notice to the owners and tenants of the property and of adjacent, confronting and abutting properties. A notice fee is collected with the application. Review stays ministerial, with no public hearing.
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Neighborhood Notification and Fees, accessed 2026-10-23.

Recorded deed restriction
Before the building permit is issued, you record a deed restriction with the Alameda County Clerk-Recorder. It bars short-term rental of the ADU or junior ADU and limits selling it separately from the main home.
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Recorded Deed Restriction, accessed 2026-10-23.

New address
Every ADU except a junior ADU needs a new address. Submit the address assignment request (with its fee) to the Building and Safety Division before the building permit is issued.
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Address Assignment, accessed 2026-10-23.

City impact fees
The Land Use Planning Division does not charge impact fees for ADUs. Use the City's Permit Fee Estimator for building permit fees.
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Permit Fees, accessed 2026-10-23.

All-electric rule
Newly built ADUs must meet Berkeley's Electrification Reach Code (local amendment to the Berkeley Energy Code, BMC Chapter 19.36).
Source: City of Berkeley, Residential Additions and Accessory Dwelling Units page, Other Requirements, accessed 2026-10-23.

City ADU Plans Gallery
Permit applications using a design from the City's Plans Gallery get plan check fees at 50% of the usual cost. Design changes are not accepted; a changed design goes through normal processing. Contact the Land Use Planning Division about zoning limits before choosing a design.
Source: City of Berkeley, “Pre-Approved” Designs for Accessory Dwelling Units page, How it works, accessed 2026-10-23.

California state rules on file

The statewide baseline recorded from state law and the HCD ADU Handbook.

Detached size cap described in state law
1,200 sq ft. Recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Side and rear setback cap for a new ADU
4 ft. Recorded in this rules file from Government Code section 66314, which describes a cap on side and rear setbacks for a new ADU.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Setback for a conversion of an existing structure
No additional setback, as recorded in this rules file from Government Code section 66314 for a conversion of an existing structure.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum lot size
A city may not impose a minimum lot size for an ADU, as recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum unit the handbook says cities must allow
At least an 800 sq ft ADU with 4 ft side and rear setbacks. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(3).
Source: HCD ADU Handbook, 66321(b)(3); handbook updated March 2026, accessed 2026-10-16.

Detached height described in the handbook
16 ft, or 18 ft or 20 ft in some cases. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(4).
Source: HCD ADU Handbook, 66321(b)(4); handbook updated March 2026, accessed 2026-10-16.

Permit decision deadline
60 days. Recorded in this rules file from Government Code section 66317(a)(3): the permitting agency must decide on (approve or deny) a completed ADU application within 60 days when an existing single-family or multifamily dwelling is on the lot. Section 66317(a)(1) says the application is considered ministerially, without discretionary review or a hearing.
Source: California Government Code section 66317, 66317(a)(1), (a)(3), accessed 2026-10-17.

Owner-occupancy requirement
None. Recorded in this rules file from Government Code section 66315: a local agency may not impose an owner-occupancy requirement on an ADU. It may require that the property be used for rentals of terms 30 days or longer. The HCD ADU Handbook (updated March 2026) describes the same rule.
Source: California Government Code section 66315, 66315; HCD ADU Handbook updated March 2026, accessed 2026-10-17.

Parking near public transit
No parking standards within one-half mile walking distance of public transit. Recorded in this rules file from Government Code section 66322(a)(1). Section 66322(a) lists several other cases where parking standards may not be imposed.
Source: California Government Code section 66322, 66322(a), accessed 2026-10-17.

Ministerial categories
The HCD ADU Handbook (updated March 2026) states that Government Code section 66323 sets four ministerial categories. This rules file does not restate those four categories.
Source: HCD ADU Handbook, 66323; handbook updated March 2026, accessed 2026-10-16.

Fire Hazard Severity Zones
If your lot is in a Fire Hazard Severity Zone, the CAL FIRE Office of the State Fire Marshal says in Information Bulletin 25-004 (issued March 3, 2025): “Fire Hazard Severity Zones (FHSZs) should not restrict the development of Accessory Dwelling Units (ADUs). However, additional building standards may be necessary, including but not limited to California Fire Code Chapter 49 and California Building Code Chapter 7A.” State ADU law does not itself bar an ADU there. A city or county may still apply its building code, including wildfire-resistant construction (Gov. Code 66314(d)(8)); require side and rear setbacks “sufficient for fire and safety” for a unit converted under 66323(a)(1); and decline parking in setbacks on specific fire and life safety findings (66314(d)(10)(B)). It may also consider public safety when it designates where ADUs may be permitted (66314(a)). Sprinklers can't be required in an ADU or JADU if the primary residence doesn't need them (66314(d)(12), 66323(d)). Some cities and counties still apply their own fire-zone limits. Where this summary has one, it is listed with the local rules. This summary does not look up your lot. Check the CAL FIRE Fire Hazard Severity Zone map viewer linked from the State Fire Marshal's Fire Hazard Severity Zones page: https://experience.arcgis.com/experience/5065c998b4b0462f9ec3c6c226c610a9
Source: CAL FIRE Office of the State Fire Marshal Information Bulletin 25-004, page 4, issued March 3, 2025; Gov. Code 66314, 66323, accessed 2026-10-20.

State baseline on the directory → · State ADU rules on the homepage →

Can I build an ADU in Berkeley?

State law sets a baseline for ADUs in Berkeley, and the local standards on file are listed on this page. Whether a specific lot can add an ADU depends on zoning, utilities, and other site facts this page does not measure. Confirm with City of Berkeley Planning and Development, or run a free address summary.

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