Verified September 30, 2026

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

✓Detached ADU
✓Attached ADU
✓JADU (Junior ADU)
✓Garage Conversion
Units per single-family lot: up to 3 (ADU + JADU + detached ADU)✓ No owner-occupancy required

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

Sewer: Connection to East Bay Municipal Utility District (EBMUD) sewer system; lateral capacity verification required for detached ADUs
Fire Sprinklers: Not required unless the primary structure requires them
Parking: No additional parking required

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)
Disclaimer: Information is compiled from publicly available municipal codes for general informational purposes only. It does not constitute legal, zoning, or construction advice. Regulations change frequently. Always verify with your local planning department. Last verified: September 30, 2026. Verify with City of San Leandro Community Development Department: Planning Division

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

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