Barndominiums are widely accepted across most counties.
The Idaho Division of Building Safety administers the state building code. All jurisdictions must enforce it, but rural areas tend to have more practical application.
Primary Code
Idaho Building Code
Code Version
2018 IBC / 2018 IRC with ID amendments
Adoption Level
Statewide
Statewide Enforcement
Yes
Rural counties process permits quickly. Boise metro area has longer timelines.
Residential
Required
Commercial
Required
Agricultural
Not Required
Size threshold: structures under 200 sq ft may be exempt.
Agricultural buildings on agricultural land may be exempt from building permits. Exemption applies to buildings used exclusively for farming purposes.
Accessory structures under 200 sq ft typically exempt.
Significant snow loads in mountainous areas. Southeast Idaho near Yellowstone has higher seismic requirements. Wind loads are generally moderate.
Wind Load
85–115 mph
low zone
Snow Load
20–100+ psf
Seismic
A–D
Category
Flood
FEMA Regulated
Energy Code
IECC
Version
2018 IECC
Energy code enforced statewide through the Division of Building Safety.
License Type
Public Works Contractor license
Idaho requires contractor registration with the Bureau of Occupational Licenses. Public works contractor license required for government projects.
Front
25–30 ft
Side
5–15 ft
Rear
15–25 ft
Setbacks vary by county. Agricultural zones have generous setbacks due to large lot sizes.
Frost depth varies from 24-48 inches depending on elevation and location.
Very popular. Streamlined permitting in rural areas.
Agricultural exemptions available. Steel barns common for livestock and hay storage.
Widely accepted, especially in rural areas. Idaho is a barndo-friendly state.
Standard permit requirements in cities. Rural areas more flexible.
Full IBC compliance required.
HOAs are uncommon outside Boise suburbs. Most rural Idaho land is unrestricted.
Flood zones along the Snake River and other major waterways. FEMA flood zone maps apply.
Verify the information above directly from these official sources. Regulations change — always confirm with your local building department before starting construction.
Disclaimer: This guide is for informational purposes only and does not constitute legal or professional advice. Building codes, permit requirements, and zoning regulations change frequently. Always verify current requirements with your local building department, planning office, or a licensed professional before starting construction. Homestead Steel Structures & Design is not a legal authority on building codes or zoning regulations. Last updated February 2026.
