Solano County, CA Building Setbacks & Zoning: Structure Height Limits (2026)
Key Facts
- Height limit
- 35 feet, main building
- Governing table
- Table 28.31B, Sec. 28.31.30
- Applies in
- R-R 2-1/2, R-R 5, R-R 10 districts
- Min. lot area
- 2.5, 5, or 10 acres
- Solar rooftop bonus
- +5 feet above roof (Sec. 28.93)
- Height exceptions
- Chimneys, towers, airport zones, Sec. 28.93
- Default penalty
- Up to $1,000 fine / 6 months jail
Summary
Solano County's Rural Residential districts cap main buildings and accessory dwelling units at 35 feet under Table 28.31B of the zoning code. The limit applies uniformly across the R-R 2-1/2, R-R 5, and R-R 10 districts that cover most unincorporated residential parcels, alongside minimum lot sizes of 2.5, 5, and 10 acres and yard setbacks tied to Section 28.93. Owners who need extra height must qualify for a specific exception in the code.
28.31.30 Rural Residential Districts General Development Standards
A. General site and building standards. Subdivisions, new land uses, main buildings inclusive of primary dwellings, accessory dwelling units, and alterations to existing land uses and buildings shall be designed, constructed, and/or established in compliance with the applicable development standards delineated or referenced in Table 28.23B.
TABLE 28.31B Development Standards for Main Building(1) and Accessory Dwelling Unit Development Feature / Requirement by Zoning District: R-R 2-1/2, R-R 5, R-R 10 ... Height limit Maximum allowed height of structures. See also: Sect. 28-80 (wind turbine generators), Sect. 28-93 (height exceptions), and Sect. 28-99 (Airport Flight Obstruction Areas)
35 feet
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 1868, passed April 9, 2026).
Full Breakdown
30, Rural Residential Districts General Development Standards, sets a 35-foot maximum height for the main building and any accessory dwelling unit on parcels zoned R-R 2-1/2, R-R 5, or R-R 10, the three Rural Residential designations that cover most of the unincorporated county's residential acreage outside Fairfield, Vacaville, Vallejo, Benicia, Suisun City, Dixon, and Rio Vista. 5, 5, and 10 acres for those three districts, minimum lot frontage of 40 feet (30 feet for a flag lot or cul-de-sac lot), and yard setbacks of 30 feet in front (or 50 feet from the street centerline, whichever controls), 10 feet on each side, and 25 feet in the rear, with 10 feet required between separate structures on the same lot.
30 directs that other setbacks required for specific listed uses in Table 28-31A control instead, and detached accessory buildings follow the separate standards in Table 28-31C, which carries its own 35-foot cap plus a 60-foot front setback (60 feet for private stables). The 35-foot cap is not absolute. 99 near Travis Air Force Base. Roof-mounted solar energy systems may add up to five feet above the roof surface on top of the underlying limit. 32C applies to the parcel's zoning district, so an ADU cannot be built taller than the primary dwelling's district allows without the same exceptions.
Violations & Fines
Solano County Code Section 1-21 sets the default penalty for any code violation lacking its own specific penalty, including an over-height or unpermitted structure: up to six months in county jail, a fine up to $1,000, or both. Section 1-20 separately lets the county treat an uncorrected code violation as a public nuisance and abate it civilly. Building & Safety Services withholds approval on plans that exceed the district's height limit until the applicant secures a use permit or qualifies for a Section 28.93 exception.
Frequently Asked Questions
How tall can I build a house in unincorporated Solano County?
Can I build higher than 35 feet for a water tank or tower?
Do rooftop solar panels count against my 35-foot height limit?
What happens if I build a structure taller than the code allows?
Sources & Official References
Other rules in Solano County
California rules heatmap·Compare Solano County to another location·View the California building setbacks & zoning overview
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