ADU Rules in Berkeley, CA (2026)
ADU rules, permit requirements, size limits, and fees for Berkeley, CA. Source-cited from official municipal code.
Yes, ADUs are allowed in Berkeley, CA.
Berkeley, CA permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. California state law actively preempts local restrictions, making ADU approval a streamlined ministerial process. In Berkeley, the Berkeley Planning and Development Department — Building Services handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Berkeley.
ADU Size Limits
ADU Size Limits in Berkeley: Detached ADU: up to 1200 sq ft (max height: 16 feet). Attached ADU: 50 percent of the existing primary dwelling. Junior ADU (JADU): up to 500 sq ft — must be within the existing primary dwelling or accessory structure. Detached ADU maximum 1,200 sqft per California Gov Code §66314(d)(5) (Stats. 2024 Ch. 7 §20). JADU maximum 500 sqft within existing primary structure per Gov Code §66333 (Stats. 2024 Ch. 7 §20). Berkeley has some of the highest rental rates in the Bay Area — even a small JADU can rent for $2,500–$4,000/month due to UC Berkeley proximity. Berkeley BMC Section 23C.24.110.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | See official source | See official source |
| Attached ADU | 50 percent of the existing primary dwelling · Verified June 4, 2026 · Source | See official source |
| JADU | 500 sq ft · Verified June 4, 2026 · Source | Within existing structure |
Permit Fees
ADU Permit Fees in Berkeley: Plan check fee: $700–$4,000. Building permit fee: $1,200–$5,500. Impact fees: None. School fees: Exempt for ADUs under 750 sqft. ADUs 750+ sqft subject to Berkeley Unified School District developer fees.. Total estimated permit cost: $2,500–$10,000 total permit fees. Impact fees waived for ADUs under 750 sqft per Gov Code §66323 (Stats. 2024 Ch. 7 §20). EBMUD connection fees for new water/sewer service (typically $4,000–$10,000 depending on meter size). Berkeley's ADU permit fees are among the Bay Area's more transparent — full schedule at cityofberkeley.info/permits/fees. Fee schedule: https://www.cityofberkeley.info/planning/fees/
| Fee Type | Amount |
|---|---|
| Plan Check | $700–$4,000 |
| Building Permit | $1,200–$5,500 |
| Impact Fees | None |
| School Fees | Exempt for ADUs under 750 sqft. ADUs 750+ sqft subject to Berkeley Unified School District developer fees. |
| Total Estimate | See official source |
Permit Timeline
Berkeley ADU Permit Timeline: The permitting agency shall either approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the permitting agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot. Apply through the Berkeley Planning and Development Department — Building Services online permit portal. Phone: (510) 981-7440.
Setback Requirements
ADU Setback Requirements in Berkeley: Front setback: Same as zone standard. Side setback: 4 feet. Rear setback: 4 feet. 4-foot side and rear setbacks per California Gov Code §66314(d)(7) (Stats. 2024 Ch. 7 §20). Berkeley R-1 zones typically require 5 ft side and 20 ft rear setbacks for primary dwellings — ADU setbacks at 4 ft are less restrictive by state law. Berkeley's small lots (average 5,000-6,000 sqft in flatlands) mean ADU placement requires careful site planning.
Parking Requirements
Parking Requirements: No additional parking required for ADUs within one-half mile of Downtown Berkeley BART, North Berkeley BART, or Ashby BART, or AC Transit bus network routes. No replacement parking when garage converted to ADU. Per California Gov Code §66322(a)(1) and §66314(d)(11) (Stats. 2024 Ch. 7 §20).
Restrictions & Requirements
- ADU must comply with Berkeley Municipal Code Section 23C.24.110 objective standards
- Berkeley Rent Stabilization may apply to new ADUs in multifamily context — verify coverage with Berkeley Rent Board
- ADU cannot be sold separately from primary dwelling (unless Urban Lot Split per Gov Code §66411.7 applies)
- Short-term rental of ADR requires Berkeley Short-Term Rental registration
- Hillside (R-1H) properties: seismic and fire safety requirements are stricter
- Properties in UC Adjacent (UA) overlay zone may have additional design standards
How Many ADUs Are Allowed?
Number of ADUs Allowed in Berkeley: Single-family lots: 1 ADU + 1 JADU per single-family lot. Multifamily properties: Up to 25% of existing units (minimum 2) as detached ADUs; non-livable space conversions by-right per state law. Berkeley's Urban Lot Split (Gov Code §66411.7) allows lot splits in R-1 zones, potentially creating additional development opportunity. UC Berkeley proximity means strong demand for studio and 1-bedroom ADUs from graduate students and researchers.
Single-Family Lots
1 ADU + 1 JADU per single-family lot
Multifamily Properties
Up to 25% of existing units (minimum 2) as detached ADUs; non-livable space conversions by-right per state law
State Law & Preemption
State Preemption: California Government Code Chapter 13 (§§66314–66333, effective January 1, 2025 per Stats. 2024 Ch. 7, SB 477) preempts Berkeley's local ADU restrictions. Berkeley was already highly ADU-friendly before statewide preemption and had eliminated owner-occupancy requirements and setback restrictions years earlier. Owner-occupancy requirement eliminated per §66315 (AB 68, 2019; Stats. 2024 Ch. 7 §20). Berkeley Municipal Code Section 23C.24.110 implements state ADU law.
Historic District Considerations
Historic District Requirements: Berkeley has 6 historic districts where additional design review may be required for ADU construction. Design review approval is required before obtaining a building permit for properties in historic overlay zones. Berkeley has 6 designated historic districts including the North Berkeley Station District, Poets Corner, and the Claremont Hotel Historic Landmark. Berkeley also has hundreds of individually-designated landmarks (200+) under the Berkeley Landmarks Preservation Ordinance (LPO). The Landmarks Preservation Commission reviews changes to Landmarks and properties in historic districts. Berkeley has significant early 20th century architecture including Bernard Maybeck, Julia Morgan, and other Bay Region Style architects. Look up historic district boundaries at: https://www.cityofberkeley.info/planning/landmarks/
Frequently Asked Questions
Can I build an ADU in Berkeley?
Yes. Berkeley, CA allows accessory dwelling units. On a single-family lot you can build 1 ADU + 1 JADU per single-family lot.
How big can an ADU be in Berkeley?
The maximum size for a detached ADU in Berkeley is 1,200 square feet. A Junior ADU (JADU) can be up to 500 square feet.
How long does it take to get an ADU permit in Berkeley?
The typical ADU permit timeline in Berkeley is The permitting agency shall either approve or deny the application to create or serve an accessory dwelling unit within 60 days from the date the permitting agency receives a completed application if there is an existing single-family or multifamily dwelling on the lot.. Total estimated permit fees are $2,500–$10,000 total permit fees.
Do I need extra parking for an ADU in Berkeley?
Berkeley parking rules for ADUs: No additional parking required for ADUs within one-half mile of Downtown Berkeley BART, North Berkeley BART, or Ashby BART, or AC Transit bus network routes. No replacement parking when garage converted to ADU. Per California Gov Code §66322(a)(1) and §66314(d)(11) (Stats. 2024 Ch. 7 §20).
Do I have to live on-site to have an ADU in Berkeley?
Owner-occupancy requirement in Berkeley: No additional standards, other than those provided in Section 66314, shall be used or imposed, including an owner-occupant requirement.
Source: Berkeley Municipal Code Title 23, Section 23C.24.110 — Accessory Dwelling Units; California Government Code §§66314–66333 (Stats. 2024 Ch. 7 §20). Last verified April 6, 2026. View source