Vacaville, CA Accessory Structures: Tiny Homes (2026)

Solano County does not publish a standalone tiny-home ordinance for unincorporated areas. How a tiny home is treated depends on its construction. A tiny house built on a permanent foundation is regulated as a dwelling or ADU under Chapter 28 and the California Building Code, so it must meet the applicable ADU size, setback, and permit standards - for example the four-foot side and rear ADU setback, district size caps, and a minimum unit floor area of 380 square feet (with limited efficiency-unit exceptions). California ADU law (Gov. Code 66310 et seq.) governs many of these standards for counties on unincorporated land, and a permanent-foundation tiny home meeting ADU criteria gains those state protections. A movable tiny house on wheels is generally classified as a recreational vehicle or manufactured/mobile structure rather than a permanent dwelling; living in an RV on private land is restricted and is not a permitted permanent residence in most zones. Because no single section uses the phrase 'tiny home,' the safest path is to design to ADU/dwelling standards and confirm classification with the Planning Division (707-784-6765) and Building & Safety before purchasing or siting a unit.