ADUByCity
Verified March 14, 2026

ADU Regulations in San Jose, California

Santa Clara County · CA · Pop. 1,030,000

Max ADU Size

1,200

sq ft detached

Rear Setback

4 ft

Permit Timeline

60 days for ministerial review

Build Cost

$200,000 – $550,000

Zoning

Allowed ADU Types

✓Detached ADU
✓Attached ADU
✓JADU (Junior ADU)
✓Garage Conversion
Max per lot: 2 ADUs✓ No owner-occupancy required

Both an ADU and a JADU are allowed on a single-family lot simultaneously

Source: City of San Jose — Accessory Dwelling Units · San Jose Municipal Code Title 20 (Zoning)

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

side

4 ft

rear

4 ft

Max height: 16 ft (detached); 25 ft if above garage

Lot coverage: No additional lot coverage limit beyond primary dwelling requirements

Garage conversions may maintain zero setbacks from existing structure footprint

Permitting

Permit Process

Department

San Jose Department of Planning, Building & Code Enforcement

Review Timeline

60 days for ministerial review; no discretionary approval required

Permit Fees

$5,000 – $20,000

Impact Fees

Waived for ADUs 750 sq ft and under; reduced for 750–1,200 sq ft

Required Documents

  • ›Completed permit application
  • ›Site plan showing all structures and setbacks
  • ›Floor plans (existing and proposed)
  • ›Elevation drawings (all four sides)
  • ›Title 24 energy compliance documentation
  • ›Structural calculations (new construction or additions)

San Jose has a pre-approved ADU plan library to speed up permitting

Visit San Jose Department of Planning, Building & Code Enforcement →

Infrastructure

Utilities & Requirements

Solar

Required

Parking

Not required

Separate Meter

Optional

Fire Sprinklers

See note

Sewer: Must connect to municipal sewer; connection fee may apply
Fire Sprinklers: Not required unless primary dwelling has sprinklers
Parking: No additional parking required for ADUs in most zones

PG&E service area — electrical upgrade may be required depending on panel capacity

Financials

ADU Costs in San Jose

Typical Build Cost

$200,000 – $550,000

Cost per Sq Ft

$300 – $500

Monthly Rental

$2,200 – $5,500/mo

Property Value Added

Adds $250,000 – $500,000 to property value in Silicon Valley market

Available Grants & Programs

  • ★CalHFA ADU Grant Program (up to $40,000 for eligible homeowners)
  • ★Santa Clara County programs for affordable ADUs

Silicon Valley labor costs drive ADU construction prices above state averages; garage conversions typically $100,000–$200,000

Use the free ADU Cost Calculator →

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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: March 14, 2026. Verify with San Jose Department of Planning, Building & Code Enforcement

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Nearby Cities in Santa Clara County

Sunnyvale

Max 1,200 sq ft · $220,000 – $430,000

Santa Clara

Max 1,200 sq ft · $220,000 – $430,000

San Jose Quick Facts

  • Max size1,200 sq ft
  • Rear setback4 ft
  • Permit timeline60 days for ministerial review
  • Build cost$200,000 – $550,000
  • Rental income$2,200 – $5,500/mo
  • Owner occupancyNot required

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Official Source

City of San Jose — Accessory Dwelling Units

San Jose Municipal Code Title 20 (Zoning)

Last verified: March 14, 2026

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