Building Safety in Solano County, CA (2026)
7 county-level rules, plus city-specific rules for 3 cities in Solano County, California.
Verified from official government sources
Fire Sprinkler Requirements
Solano County exempts accessory dwelling units and junior accessory dwelling units from fire sprinkler installation whenever the primary residence on the same lot is not itself required to have them, per Section 28.72.10(B)(2)(o), removing a cost barrier that state ADU law also targets.
Solano County ADU Fire Sprinkler Exemption
Few RestrictionsSolano County Code § 28.72.10(B)(2)(o)
o. Fire Sprinklers. An accessory dwelling unit or junior accessory dwelling unit shall not be required to provide fire sprinklers if they are not required for the primary residence.
Green Building Code
Solano County enforces the 2025 edition of the California Green Building Standards Code (CALGreen) as part of its adopted building code family under Chapter 6.3. Every new building permit in the unincorporated county is reviewed against CALGreen's requirements alongside the Building, Residential, and Energy Codes.
Solano County Green Building Standards Code
Some RestrictionsSolano County Code Sec. 6.3-03(a), (a)(12) (Uniform Codes Adopted)
The California Building Standards Code, 2025 Edition, known as the California Code of Regulations, Title 24 (CCR, T-24) as adopted by the State of California Legislature, is adopted by reference as the Building Code of the County of Solano, incorporating Parts 1, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, known collectively as California Building Standards Code and respectively as California Admi...
Carbon Monoxide Detectors
Every Solano County vacation house rental must equip the dwelling and each individual bedroom with functional smoke and carbon monoxide alarms, and keep at least one working, clearly marked fire extinguisher on site, under Section 28.75.30(A)(7)(e) of the county code, part of the fire-safety conditions of the short-term rental permit.
Solano County Vacation Rental Smoke/CO Alarms
Some RestrictionsSolano County Code § 28.75.30(A)(7)(e)
e. The dwelling and each bedroom shall be equipped with functional smoke and carbon monoxide alarms. At least one functional fire extinguisher shall be available and readily marked.
Building Permits
Solano County requires a building permit for nearly all construction under the adopted California Building Code, but Code Sec. 6.3-20 carves out three narrow local exemptions: small satellite dishes, small agricultural outbuildings, and most fencing. Everything else, including additions, new dwellings, and structural work, needs a permit from the Building and Safety Division before work starts.
Solano County Building Permit Exemptions
Some RestrictionsSolano County Code Sec. 6.3-20 (California Building Code Section 105.2 Amended - Exemptions from Building Permit)
Section 105.2 of the California Building Code is amended to add the following exemptions from a building permit: (a) Satellite dish antennas, unless attached to a structure or mounted more than 15 feet above the ground (b) Purely agricultural, nonresidential buildings and/or structures not exceeding 500 square feet and with no structural span exceeding 14 feet. The family residing on the prem...
Electrical Permits
Solano County enforces the 2025 California Electrical Code for all wiring work, adopted by reference in Chapter 6.3, and layers on two local amendments: commercial buildings must run conductors in rigid conduit, EMT, or approved flex/PVC, and new houses over 1,500 square feet need at least a 200-amp main service panel.
Solano County Electrical Permit Code
Some RestrictionsSolano County Code Sec. 6.3-22, 6.3-23 (California Electrical Code Amendments)
California Electrical Code Section 230.79(C) is amended to add: All new single family dwellings in excess of fifteen hundred square feet of living area will be equipped with minimum two hundred amp main service panels. ... 6.3-22 Commercial buildings--conduit required: All electrical conductors in commercial buildings or structures shall be in rigid conduit, EMT or where permitted flex or PVC.
Plumbing Permits
Solano County will not issue a grading, building, or plumbing permit for any project needing new potable water service until the applicant proves the water source is adequate under Code Sec. 6.3-52. That means a letter from a public water purveyor, a connection permit, or a tested and certified on-site well, spring, or surface supply.
Solano County Plumbing Permit Water Rule
Some RestrictionsSolano County Code Sec. 6.3-52 (California Plumbing Code - Verification of Water Supply Required)
No grading, building or plumbing permit application or plans for a project which will require new service with potable water shall be issued unless: (1) The building official is provided a written statement from the operator of an approved public water agency that the purveyor will provide potable water service to the dwelling and that the water purveyor has sufficient water resource and syste...
Building Inspections
Solano County requires inspections at every stage of a permitted project and locks the final inspection under an amended California Building Code Sec. 110.3.10: it cannot pass until all electrical, plumbing, mechanical, floor covering, painting, and required landscaping work is complete and the site is clean.
Solano County Building Inspection Requirements
Some RestrictionsSolano County Code Sec. 6.3-18 (California Building Code Section 110.3.10 Amended - Final Inspection)
Final Inspection shall be made after final grading and the building is completed and ready for occupancy. This shall mean all work required by the building permit, all electrical, plumbing and mechanical complete and ready for occupancy, as well as all floor covering installed and painting completed, as well as any required exterior landscaping complete with house, sidewalks, and streets cleaned.
Building Safety by City in Solano County
3 cities in Solano County have their own building safety rules. Each link goes to that city's dedicated page with code citations.
All Solano County ordinances
See every category we cover for Solano County: parking, noise, fences, fires, animals, pools, and more.
Solano County Ordinance Hub →