The Snake River in a sheer basalt canyon below the flat Magic Valley rim, with green center-pivot fields stopping at the canyon edge.
Blaine County, Idaho Twin Falls & the Magic Valley

Barndominium Builders in Blaine County, Idaho

Blaine County runs from the high, snowy north end of the Wood River Valley down to the open farm and ranch ground around Picabo and Carey, and the right barndominium changes along the way. On the southern flats a long equipment shop, a hay barn beside the house or a horse setup is common. Toward the valley's north end the county's published roof snow loads rise to three times the Carey figure, so the building needs heavier framing and a roof designed to shed it. On unincorporated land the county's Land Use staff review zoning first, and Building Services then reviews the structure. Barndominium kits suit an owner with a crew ready to go, and pole barn homes give the widest clear span for the money on farm parcels. Our turnkey builds cover the whole job, from site preparation to the final inspection. For a lot inside town, the Hailey page covers the city process. Send your parcel through the survey and we will check the zone, the snow-load area and the septic route before any design work.

Blaine County at a glance

County
Blaine County
Building permit
County building department
Land use
County agricultural and rural zoning
Wastewater
Septic permit: Public Health District

Pole Barn Homes near Blaine County

A pole barn home sets its frame on posts and trusses (the engineering term is post-frame), which often suits a simple, wide layout with a shop bay under the same roof. Whether it fits your parcel comes down to the zoning and the site, set out below.

Permits, Zoning and Septic in Blaine County

The building permit, the zoning and the septic permit can come from three different offices. Here is who decides each part in Blaine County, taken from the office or document that publishes it. Rules change, so check them again against your parcel before anything is drawn.

Who issues the building permit County building department

Blaine County Building Services

On unincorporated land Blaine County Building Services issues building permits, now through a digital-only online portal, and inspections are requested by phone with the office. Each application is reviewed in-house for zoning by Land Use staff before the structural review. Most cities, Hailey among them, run their own building permits inside their limits.

Source: Building Services, Blaine County (blainecountyid.gov)

Who decides the land use Agricultural and rural zones

Blaine County Land Use Services

Blaine County names A-20, A-40 and RR-40 among its agricultural zoning districts. Every application gets an in-house review by Land Use staff, and if a zoning application is needed, a hearing before the Planning and Zoning Commission or a Hearing Examiner may follow, so the county advises checking with Land Use staff before applying.

Source: Building Services FAQs, Blaine County (blainecountyid.gov)

Sewer or septic Septic: Public Health District

South Central Public Health District

Blaine County is served by South Central Public Health District, whose Environmental Health Specialists issue permits for new, enlarged and replacement septic systems. Every septic system in Idaho needs an installation permit.

Source: Land Development, South Central Public Health District (phd5.idaho.gov)

Roof snow loads by location
Blaine County publishes the roof snow loads permitted structures are designed to by location: 50 pounds per square foot in the Carey Valley, 65 from Picabo to south of Bellevue, 100 from north of Bellevue to south of Ketchum, and up to 150 from North Fork to Smiley Creek (Building Services FAQ, read 27 Sep 2026).

Source: Building Services FAQs, Blaine County (blainecountyid.gov)

Farm buildings versus homes
The county exempts an agricultural building in the county's agricultural districts, such as A-20 and A-40, from a building permit but still requires a setback permit, and its definition says such a building shall not be a place of human habitation, so a barndominium goes through the full building permit (Building Services FAQ, read 27 Sep 2026).

Source: Building Services FAQs, Blaine County (blainecountyid.gov)

Building on land near Blaine County

Two things shape a Blaine County building before the floor plan does: the parcel's zone and its row on the county's snow-load chart. On the Carey and Picabo farm ground, look for irrigation laterals crossing the property; nothing may be built or fenced in that easement unless the ditch owner agrees in writing. Away from town there is usually no water main, so plan on drilling your own well (IDWR permit, licensed driller) and on a health-district septic permit. Up-valley sites can mean slope, long private roads and river corridors to design around. Submit plans early, since the county's review queue is longest from March to October.

Other places in this part of Idaho

Have land in or near Blaine County? Tell us about the parcel and what you want on it, and we will check it against the local rules before anything is drawn.

Building in Blaine County: questions

Start the survey
How much does it cost to build a barndominium in Blaine County?
It swings widely across the county. Snow-load framing weighs far more up-valley than on the Carey flats, and a well, septic system and driveway can add a lot on any rural parcel. We price against the actual site. Our barndominium cost guide sets out sourced ranges and what moves them.
Do I need a building permit for a barndominium in Blaine County?
Yes. On unincorporated land Blaine County Building Services issues the building permit after an in-house zoning review, and the county says processing usually takes about four weeks in the March-to-October season. The farm-building exemption does not apply to a home. Electrical, plumbing and HVAC work carries separate permits pulled by licensed trade contractors.
Which zones in Blaine County suit a barndominium on acreage?
The county lists A-20, A-40 and RR-40 among its agricultural districts, and a barndominium on acreage will usually sit in one of them. The parcel's zone, its setbacks and any need for a hearing are confirmed by Land Use staff. Send us the parcel through the survey and we will check the zone before design.
How much snow does a Blaine County roof have to carry?
It depends on where you build. The county's chart runs from 50 pounds per square foot of roof snow load in the Carey Valley to 150 at the far north end of the valley, and the building official confirms the figure for your site at plan review. That load drives the roof pitch, framing and the overall cost.

Other places near Blaine County

Nearby places with their own pages. Across a city limit or a county line the permit office, the zoning and the septic rules can change, so each is covered separately.

Building in Blaine County?

Start with the survey. Tell us where the land is and what you want on it, and we will come back with which offices decide it, what the zoning allows, and a plan to fit.