ADU Regulations in San Leandro, California
Alameda County · CA · Pop. 90,000
San Leandro waived Park Impact Fees and street improvement fees for all ADUs in July 2025, regardless of size. Detached ADUs can reach 1,200 sq ft where 50% of the main house allows it, and 18 ft within half a mile of BART or another major transit stop. The city points homeowners to the Alameda County ADU Resource Center for step-by-step help.
Max ADU Size
1,200
sq ft detached
Rear Setback
4 ft
Permit Timeline
60 days
Build Cost
$175,000 – $360,000
Local Rules
What's Different in San Leandro
- ›Park and street improvement impact fees waived for all ADUs since July 2025
- ›Detached ADU height 16 ft, 18 ft near major transit
- ›ADUs over 1,000 sq ft must meet lot coverage and FAR limits
- ›No short-term rentals in ADUs
Zoning
Allowed ADU Types
State law requires cities to allow, on a single-family lot, one ADU converted from existing space, one JADU, and one new detached ADU of up to 800 sq ft. Multifamily lots can add up to 8 detached ADUs (not more than the number of existing units) plus conversions of non-livable space for up to 25% of existing units.
San Leandro is an East Bay city directly south of Oakland with strong BART connectivity. The city has actively encouraged ADU development as part of its housing element to accommodate Oakland spillover demand. Industrial corridors are transitioning to mixed residential use.
Source: City of San Leandro: Accessory Dwelling Units · San Leandro Zoning Code Section 2.04.388
Dimensions
Size & Setback Requirements
Detached
1,200
sq ft max
JADU
500
sq ft max
Attached
50% of primary home, max 1,200 sq ft
Setbacks
front
Same as primary dwelling per underlying zone
side
4 ft
rear
4 ft
Max height: 16 ft (detached); up to 18 ft if within half-mile of major transit stop
State law floor for detached ADUs: 16 ft; 18 ft within half a mile of major transit (plus 2 ft to match the main roof pitch) or on a lot with a multistory multifamily building.
Lot coverage: Per underlying zone; typically 50–60% in RS zones
San Leandro's proximity to the San Leandro BART station creates transit-rich opportunities for ADU rentals. Lots within half a mile of the BART station may qualify for increased height allowances under state transit-area provisions.
Permitting
Permit Process
Department
City of San Leandro Community Development Department: Planning Division
Review Timeline
60 days
Permit Fees
$9,000 – $18,000
Impact Fees
Park Impact Fees and Development Fees for Street Improvements waived for all ADUs (Resolutions 2025-106 and 2025-107, July 2025); state law waives impact fees under 750 sq ft
Required Documents
- ›Site plan (to scale, showing lot dimensions, all structures, setbacks)
- ›Floor plans
- ›Elevations
- ›Title 24 energy compliance (residential)
- ›Structural drawings
- ›Stormwater management plan (for larger ADUs)
San Leandro has a well-staffed planning department that processes ADU applications efficiently. The city's online portal allows digital submission and status tracking. East Bay construction labor costs are comparable to Oakland and Berkeley.
Infrastructure
Utilities & Requirements
Solar
Required
Parking
Usually none
Separate Meter
Optional
Fire Sprinklers
Only if main home has them
Financials
ADU Costs in San Leandro
Typical Build Cost
$175,000 – $360,000
Cost per Sq Ft
$245 – $320
Monthly Rental
$1,800 – $2,900/mo/mo
Property Value Added
Adds $200,000 – $370,000 to property value
Grants & Programs to Check
- ★CalHFA ADU Grant Program (closed since December 2023; watch calhfa.ca.gov for any new funding round)
- ★Alameda County ADU assistance programs; check with county housing authority
San Leandro benefits from Oakland's extremely tight rental market, drawing renters who cannot afford Oakland prices. BART access at the San Leandro station makes car-free commuting viable. The city's industrial heritage is giving way to mixed residential development, boosting long-term property values.
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State Law
California Rules That Apply in San Leandro
San Leandro can be more generous than state law but not stricter. These statewide minimums were last reviewed September 30, 2026.
- Units per lot
- Single-family lots can have one ADU converted from existing space, one JADU, and one new detached ADU (up to 800 sq ft). Multifamily lots can add up to 8 detached ADUs (never more than the number of existing units) plus conversions for up to 25% of existing units. Gov. Code §66323; SB 1211 (2024)
- Size
- Cities must allow at least an 800 sq ft ADU with 4 ft side and rear setbacks. Local maximums can be no lower than 850 sq ft (studio or one bedroom) or 1,000 sq ft (two or more bedrooms). JADUs are capped at 500 sq ft of interior livable space. Gov. Code §§66321, 66333
- Height
- Detached ADUs: at least 16 ft; 18 ft within half a mile of major transit (plus 2 ft to match the roof pitch of the main home) or on a lot with a multistory multifamily building. Attached ADUs: 25 ft or the zone height limit, whichever is lower. Gov. Code §66321(b)(4); AB 2221 and SB 897 (2022)
- Setbacks
- Side and rear setbacks for new ADUs can be no more than 4 ft. Conversions of existing legal structures need no extra setback. Front setbacks cannot block an 800 sq ft ADU. Gov. Code §66314(d)(7); AB 2221 (2022)
- Permit timeline
- The city has 15 business days to say whether an application is complete, or it is deemed complete. It must then approve or deny a complete application within 60 days, with no public hearing. Gov. Code §66317; SB 543 (2025)
- Impact fees
- No impact fees on ADUs under 750 sq ft; larger units pay fees proportional to the main home. ADUs and JADUs of 500 sq ft or less are exempt from school impact fees. Gov. Code §66324; SB 543 (2025)
- Owner-occupancy
- Cities cannot require the owner to live on site for an ADU. For a JADU, owner-occupancy can be required only if the JADU shares a bathroom with the main home. JADUs cannot be short-term rentals. AB 976 (2023); AB 1154 (2025)
- Parking
- No parking is required for an ADU within half a mile walk of public transit, in a historic district, or for a conversion, and garage parking lost to an ADU does not have to be replaced. Gov. Code §66322
- Fire sprinklers
- Sprinklers cannot be required in an ADU unless the main home is required to have them. Gov. Code §66314(d)(12)
- Pre-approved plans
- Every city must offer a program for pre-approved detached ADU plans, and plans matching a pre-approved design must be approved or denied within 30 days. AB 1332 (2023); Gov. Code §65852.27
- Selling an ADU
- Cities may choose to let owners sell an ADU separately as a condominium. It is a local opt-in, so check whether your city has adopted it. AB 1033 (2023)
- Unpermitted ADUs
- ADUs built without permits before 2020 can be legalized. Cities cannot deny them for code violations unless the unit is a health and safety hazard, and fees are limited. AB 2533 (2024)
Sources
- City of San Leandro: Accessory Dwelling Units (San Leandro Zoning Code Section 2.04.388)
- City of San Leandro ADU Handout
- California HCD Accessory Dwelling Unit Handbook
Compiled by the ADUByCity Team. How we verify city data.
San Leandro Quick Facts
- Max size1,200 sq ft
- Rear setback4 ft
- Permit timeline60 days
- Build cost$175,000 – $360,000
- Rental income$1,800 – $2,900/mo/mo
- Owner occupancyNot required
Official Source
City of San Leandro: Accessory Dwelling UnitsSan Leandro Zoning Code Section 2.04.388
Last verified: September 30, 2026
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