ADU Regulations in Vacaville, California
Solano County · CA · Pop. 102,000
Max ADU Size
1,200
sq ft detached
Rear Setback
4 ft
Permit Timeline
60 days
Build Cost
$140,000 – $285,000
Zoning
Allowed ADU Types
State law preempts local owner-occupancy requirements. Vacaville's planned residential communities offer large lots suitable for detached ADUs. One ADU plus one JADU permitted per single-family lot.
Source: City of Vacaville — Accessory Dwelling Units · Vacaville Municipal Code Chapter 14.04 (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
Lot coverage: Per underlying zone
Many Vacaville subdivisions feature generous rear yards accommodating full-size detached ADUs. Garage conversions retain existing setbacks. Some newer planned developments may have HOA CC&Rs that are superseded by state ADU law.
Permitting
Permit Process
Department
City of Vacaville Community Development Department — Planning Division
Review Timeline
60 days
Permit Fees
$5,500 – $11,000
Impact Fees
Impact fees waived for ADUs under 750 sq ft per state law
Required Documents
- ›Site plan
- ›Floor plans
- ›Elevations
- ›Title 24 energy compliance
- ›Structural drawings
- ›Drainage and grading plan (if applicable)
Vacaville uses ministerial ADU approval per state law with no discretionary review required. The Planning Division offers pre-application meetings to streamline the process. Travis Air Force Base proximity creates strong demand for rental housing and may influence design preferences.
Visit City of Vacaville Community Development Department — Planning Division →Infrastructure
Utilities & Requirements
Solar
Required
Parking
Not required
Separate Meter
Optional
Fire Sprinklers
See note
Financials
ADU Costs in Vacaville
Typical Build Cost
$140,000 – $285,000
Cost per Sq Ft
$195 – $260
Monthly Rental
$1,400 – $2,200/mo/mo
Property Value Added
Adds $150,000 – $280,000 to property value
Available Grants & Programs
- ★CalHFA ADU Grant Program available
- ★Solano County housing assistance programs
Vacaville's strategic location on I-80 between Sacramento and the Bay Area makes it a popular choice for commuters seeking affordable housing. Travis AFB military families and NorCal commuters provide a reliable, diverse renter pool. Construction costs are lower than Bay Area markets while rental rates remain solid.
Use the free ADU Cost Calculator →Free Service
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Nearby Cities in Solano County
Vacaville Quick Facts
- Max size1,200 sq ft
- Rear setback4 ft
- Permit timeline60 days
- Build cost$140,000 – $285,000
- Rental income$1,400 – $2,200/mo/mo
- Owner occupancyNot required
Official Source
City of Vacaville — Accessory Dwelling UnitsVacaville Municipal Code Chapter 14.04 (Zoning)
Last verified: March 14, 2026
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