California ADU rules · Alameda County
Can I Build an ADU in Oakland?
Yes — you can build an ADU in Oakland. California's statewide ADU law requires every city, including Oakland, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
Local rule1 detached/attached ADU + 1 conversion ADU + 1 JADU (up to 3 units)
Oakland lets a homeowner create one Category One (conversion) ADU, one Category Two (detached/attached) ADU, and one JADU — three units beyond the primary, more than the state's '1 ADU + 1 JADU' baseline framing.
Units on a multifamily lot
Local ruleConversion ADUs (≥1, up to 25% of existing units) + up to 2 detached, not more than 8 total
Oakland caps new-construction (Category Two) detached ADUs on a multifamily lot at 2, alongside conversion ADUs of up to 25% of existing units, not exceeding 8 ADUs total. Confirm the detached cap against the current table.
Junior ADU (JADU)
CA state lawAllowed
Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).
Size & height
Max detached ADU size
Local rule1,000 sq ft
Local cap below the 1,200 sq ft state default: 850 sq ft for a studio/1-bedroom, 1,000 sq ft for 2+ bedrooms. A conversion ADU may expand up to 150 sq ft for ingress/egress.
Max attached ADU size
Local rule850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms), and not more than 50% of the primary dwelling's floor area unless that would undercut those minimums
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
Setbacks
Side setback
Local rule4 ft
4 ft or the regularly required setback, whichever is less, but never less than 3 ft — so Oakland can permit a 3-ft side setback where the base zone requires less than 4 ft.
Rear setback
Local rule4 ft
4 ft or the regularly required setback, whichever is less, but never less than 3 ft.
Front setback
CA state lawNo front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
CA state lawUp to 1 space
At most 1 space per ADU (or per bedroom, whichever is less) — and waived in the common cases below.
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
CA state lawNot required
When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
CA state lawOnly for a JADU
No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
CA state lawBuilding permit
Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.
Oakland-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
S-9 Fire Safety Protection Combining Zone (VHFHSZ)
In the S-9 combining zone covering the East Bay hills, new-construction ADUs are restricted — height is capped at 16 ft and additional/replacement parking and limited ADU types may apply unless a specific exception is met.
Historic districts & landmarks
An ADU visible from the street on a property in the California Register of Historic Resources must meet objective design standards; alternative finishes may be approved through Small Project Design Review.
S-10 Scenic Route Combining Zone & hillside overlays
Lots in the S-10 scenic-route zone and other hillside overlays may trigger additional design review for an ADU.
Oakland allows up to three units on a single-family lot (one detached/attached ADU, one conversion ADU, and one JADU) but caps detached ADU size below the state default at 850/1,000 sq ft. The East Bay hills are the binding constraint: the S-9 Fire Safety Protection Combining Zone restricts new-construction ADUs, caps height at 16 ft, and can require additional parking.
Frequently asked questions
Can I build an ADU in Oakland?
Yes. California's statewide ADU law requires Oakland to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Oakland?
A detached ADU of at least 1,000 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Oakland?
Side and rear setbacks are limited to 4 ft. No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone.
Is parking required for an ADU in Oakland?
Up to 1 space. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Oakland?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Oakland?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Oakland Planning Code § 17.103.080 & Table 17.103.01 (Ord. 13856)
- Oakland Planning Code Table 17.103.01, Note 1
- Oakland Planning Code Table 17.103.02, Note 1
- Oakland Planning Code Table 17.103.01, Note 3
- Oakland Planning Code Table 17.103.01
- Oakland Planning Code § 17.88.050
- Oakland Planning Code § 17.103.080(A)(10)
- Oakland Planning Code § 17.90.030
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- Cal. Gov. Code § 66314 (local ordinance standards)
- Cal. Gov. Code § 66315 (owner-occupancy)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated 2026-06-25. This is an AI-assisted summary of Oakland's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Oakland Planning before relying on it.
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