Yes, Tiny homes are legal in Idaho, but their compliance hinges on zoning, building codes, and classification (permanent vs. recreational). Idaho’s 2023 adoption of the 2018 International Residential Code (IRC) Appendix Q for tiny homes streamlined permitting, yet local jurisdictions retain authority. The Idaho Building Code Board enforces these standards, while counties like Ada and Kootenai impose additional restrictions.
Key Regulations for Tiny Homes in Idaho
- Building Codes: Must adhere to IRC Appendix Q if ≤400 sq. ft. and classified as permanent dwellings. Recreational tiny homes (≤320 sq. ft.) fall under ANSI A119.5/RV standards unless permanently sited.
- Zoning: Most counties prohibit tiny homes in residential zones unless classified as ADUs (Accessory Dwelling Units). Blaine County (Sun Valley) and Boise require conditional use permits for standalone tiny homes.
- Utility Requirements: Permanent tiny homes must connect to municipal water/sewer or comply with Idaho Department of Environmental Quality (DEQ) on-site wastewater rules. Off-grid systems require health department approval.
Local ordinances often override state guidelines. For example, the City of Coeur d’Alene’s 2024 update mandates tiny homes meet R-3 residential standards, effectively barring them from single-family zones. Always verify with the Idaho Building Code Board and county planning departments before construction.