Mariposa County, CA Accessory Structures: Tiny Homes (2026)

Mariposa County's tiny-home guidance is the California HCD Information Bulletin 2016-01 (Tiny Homes), provided through the County's informational handouts. The bulletin explains that neither HCD nor any other state or local agency recognizes 'tiny home' as a standalone product category. To be legally occupied, a tiny home 'must comply with the standards of, and be approved as one of the following': a HUD-Code manufactured home (MH), a California Residential/Building Code home, factory-built housing (FBH), a recreational vehicle (RV), a park trailer (PT), or a camping cabin (CC). A site-constructed or mobile structure that does not fit the MH/FBH/RV/PT/CC definitions is a dwelling unit and 'must comply with the CBSC in order to be legally occupied,' including a minimum ceiling height of 7 feet 6 inches and at least one room of 120 sq ft of gross floor area. A movable tiny house on wheels may also qualify as an ADU under State ADU Law in some cases. In practice, a permanent tiny home built on a foundation in unincorporated Mariposa County is usually approved as an ADU, and the County's no-local-ordinance ADU framework (State Gov. Code 66310+) then applies. Tiny homes on wheels are otherwise treated as RVs/park trailers and are subject to those occupancy limits. Verify your specific structure and site with County Planning and Building.