Ada County, ID Accessory Structures: Tiny Homes (2026)
Tiny home rules in Ada County, ID, covering tiny houses on wheels (THOWs), park model RVs, and tiny home on foundation builds, determine where they are legal and how they get permitted.
Key Facts
- Code classification
- Manufactured home
- As second unit
- Follows Section 8-4-23
- Size range
- 350 to 1,200 sq ft
- On wheels
- Treated as an RV
- Code reference
- Ada County Title 8 (Ch. 10)
Summary
Ada County's zoning code treats a tiny home as a manufactured home. A tiny home used as a second unit must meet the secondary-dwelling standards of Section 8-4-23 (350 to 1,200 sq ft, foundation, deed restriction). A tiny home on wheels is a recreational vehicle, not a permanent dwelling.
Manufactured Home: A structure, transportable in one or more sections, built on a permanent chassis and designed for use as a dwelling... This includes Tiny Homes and Park Models. The term 'manufactured home' does not include a 'recreational vehicle.'
Full Breakdown
Ada County Code Title 8 defines a Manufactured Home as a structure built on a permanent chassis and designed for use as a dwelling, and states 'This includes Tiny Homes and Park Models,' while excluding recreational vehicles. A tiny home placed as a second unit on a lot is regulated as a secondary dwelling under Section 8-4-23: it must be 350 to 1,200 square feet, sit on a foundation, have separate kitchen and bath, its own address, and a recorded deed restriction, on a lot of at least 6,000 square feet. A movable tiny home on wheels is a recreational vehicle and cannot be occupied as a permanent residence outside an approved RV park. City limits follow city code.
Violations & Fines
Placing or living in a tiny home that does not meet the manufactured-home/secondary-dwelling standards is a zoning violation enforced by Ada County Development Services.
Frequently Asked Questions
Are tiny homes allowed in unincorporated Ada County?
Can I live in a tiny home on wheels?
Sources & Official References
Other rules in Ada County
Compare Ada County to another location·View the Idaho accessory structures overview
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