California ADU rules · Alameda County
Can I Build an ADU in San Leandro?
Yes — you can build an ADU in San Leandro. California's statewide ADU law requires every city, including San Leandro, 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
CA state law1 ADU + 1 JADU
At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).
Units on a multifamily lot
Local ruleconversions (>=1 or 25% of units) + up to 2 detached
Local cap of 2 detached ADUs per multifamily lot, not 4 or 8 as in state law.
Junior ADU (JADU)
Local ruleAllowed
JADUs allowed within existing or proposed single-family dwellings.
Size & height
Max detached ADU size
Local rule1,200 sq ft
Local maximum is 1,200 sq ft, subject to lot coverage/FAR/open space for >800 sq ft.
Max attached ADU size
Local rulegreater of 850 (1,000 for 2+ bedrooms) or 50% of primary, not to exceed 1,200
Attached ADUs capped at 1,200 sq ft, subject to lot coverage/FAR/open space for >800 sq ft.
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
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
Front setback
Local ruleADUs may not occupy required front yard; subject to driveway visibility
Front setback stricter than state: ADUs cannot be in required front yard.
Separation from main house
Local rule5 ft
Detached ADUs must be at least 5 ft from other structures.
Parking
Parking required
Local ruleNone
No parking required for ADUs or JADUs.
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
Local ruleNot required
No replacement parking required when converting a garage/carport.
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
Local ruleNot required
No owner-occupancy requirement for ADUs or JADUs.
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.
San Leandro limits multifamily lots to 2 detached ADUs and requires a 5-foot separation from other structures. No parking or owner-occupancy is required for ADUs or JADUs.
Frequently asked questions
Can I build an ADU in San Leandro?
Yes. California's statewide ADU law requires San Leandro 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 San Leandro?
A detached ADU of at least 1,200 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 San Leandro?
Side and rear setbacks are limited to 4 ft. ADUs may not occupy required front yard; subject to driveway visibility.
Is parking required for an ADU in San Leandro?
None. 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 San Leandro?
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 San Leandro?
Owner-occupancy: not required. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- San Leandro Zoning Code § 2.04.388 (Ord. 2022-022 § 3)
- San Leandro Zoning Code § 2.04.388(A)
- San Leandro Zoning Code § 2.04.388(B)
- San Leandro Zoning Code § 2.04.388(C)
- San Leandro Zoning Code § 2.04.388(E)
- San Leandro Zoning Code § 2.04.388(J)
- 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 § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
- 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 San Leandro'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 San Leandro Planning before relying on it.
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