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

Sierra County does not have a dedicated tiny-home chapter in its code. The practical path for a permanent tiny home is the accessory dwelling unit program in SCC 15.10.030 (Ord. 1133), which allows ADUs by right in residential zones and is approved ministerially through the building permit process. A tiny home built on a permanent foundation as an ADU must meet the same standards as any ADU: a detached unit may not exceed 1,200 square feet, is limited to 16 feet in height, and needs four-foot side and rear setbacks; the county must allow at least an 800-square-foot unit where coverage rules would otherwise block one. A junior ADU tiny dwelling within the primary home is capped at 500 square feet. Tiny homes on wheels are generally treated under California law as either recreational vehicles or, where they meet HCD movable-tiny-house standards, as a form of ADU - they are not a separate Sierra County category. SCC 32.05.250 sets floodplain standards for recreational vehicles, and the county's building exemptions (SCC 12.04.030) cover only small permit-exempt sheds and portable storage containers, not dwellings. Because every tiny home used as a residence must connect to water/wastewater and meet wildfire (CBC Chapter 7A) standards, owners on rural forest parcels should plan for septic, water, and defensible-space requirements. Always verify current rules with the Sierra County Planning Department.