Verified March 14, 2026

ADU Regulations in Vallejo, California

Solano County · CA · Pop. 125,000

Max ADU Size

1,200

sq ft detached

Rear Setback

4 ft

Permit Timeline

60 days

Build Cost

$155,000 – $310,000

Zoning

Allowed ADU Types

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

State law preempts local owner-occupancy requirements. ADUs permitted on any lot with an existing or proposed single-family or multifamily residence in residential zones.

Source: City of Vallejo — Accessory Dwelling Units · Vallejo Municipal Code Title 16 (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 per underlying zone

side

4 ft

rear

4 ft

Max height: 16 ft

Lot coverage: Per underlying zone

Detached ADUs over 850 sq ft on lots under 10,000 sq ft must comply with lot coverage limits. Existing structures converted to ADUs are not subject to increased setback requirements.

Permitting

Permit Process

Department

Vallejo Community Development — Planning Division

Review Timeline

60 days

Permit Fees

$6,000 – $12,000

Impact Fees

Impact fees waived for ADUs under 750 sq ft; prorated for larger units

Required Documents

  • Site plan with property dimensions and setbacks
  • Floor plans
  • Elevations
  • Title 24 energy compliance report
  • Structural drawings
  • Grading and drainage plan (if applicable)

Vallejo offers an over-the-counter plan check for qualifying standard ADU designs. Ferry service proximity to San Francisco has increased ADU interest significantly since 2023.

Visit Vallejo Community Development — Planning Division

Infrastructure

Utilities & Requirements

Solar

Required

Parking

Not required

Separate Meter

Optional

Fire Sprinklers

See note

Sewer: Connection to municipal sewer required; separate lateral may be required for detached ADUs
Fire Sprinklers: Not required unless primary structure requires them
Parking: No additional parking required

Financials

ADU Costs in Vallejo

Typical Build Cost

$155,000 – $310,000

Cost per Sq Ft

$215 – $275

Monthly Rental

$1,500 – $2,400/mo/mo

Property Value Added

Adds $120,000 – $220,000 to property value

Available Grants & Programs

  • CalHFA ADU Grant Program available (up to $40,000)
  • City of Vallejo may offer fee deferral programs — check with Planning Division

Ferry access to San Francisco makes Vallejo ADUs increasingly attractive to commuters priced out of the Bay Area. Rental demand is growing especially near the Vallejo Ferry Terminal.

Use the free ADU Cost Calculator →

Free Service

Get Contractor Quotes in Vallejo

Connect with licensed local ADU contractors. Takes 2 minutes, no obligation.

Get Free Quotes
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 Vallejo Community Development — Planning Division

Vallejo Quick Facts

  • Max size1,200 sq ft
  • Rear setback4 ft
  • Permit timeline60 days
  • Build cost$155,000 – $310,000
  • Rental income$1,500 – $2,400/mo/mo
  • Owner occupancyNot required

Get Free Quotes

Licensed Vallejo ADU contractors, no obligation.

Get My Free Quotes

Official Source

City of Vallejo — Accessory Dwelling Units

Vallejo Municipal Code Title 16 (Zoning)

Last verified: March 14, 2026

Stay Updated

ADU rules change often.

Get notified when Vallejo's regulations update, plus guides on permitting and financing.