Cost reference · 2026

What a Post-Frame Shop Costs in Eastern Idaho: 2026

Every figure on this page is market data with a named source. None of it is a quote, and where nothing is published, this page says so instead of filling the gap with a guess.

Mon–Fri 8am–5pm · Idaho Falls and the surrounding towns

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The gap between the kit price and the bid

Almost every disagreement about what a shop costs is really a disagreement about scope. Four price levels get quoted in this market, they differ by roughly four times end to end, and all four are described as “a shop.”

Level 1

Materials package

$8–$18

per square foot

Lumber, steel and fasteners delivered. No labour, no slab, no doors.

Level 2

Shell erected, no slab

$15–$28

per square foot

Posts, trusses, roof and walls standing. Dirt floor.

Level 3

Basic functional

$22–$42

per square foot

Shell plus slab, an overhead door and power. The point most owners mean by "a shop."

Level 4

Finished shop

$30–$60

per square foot

Insulated, heated, interior finish, full doors and utilities. Trusst Buildings of Shelley publishes $30–$60 per square foot.

The local anchor in that ladder: Trusst Buildings of Shelley publishes $30–$60 per square foot. When a $25,000 advertised kit and a six-figure bid land on the same desk, the difference is almost never that someone is overcharging — it is that one price stops at the pallet and the other ends with a building you can plug a welder into.

Completed-project medians

Steel Structures America publishes medians from its own completed projects — real finished buildings rather than a per-foot estimate.

30x40

$69,894

median across 178 projects

40x60

$119,721

median across 140 projects

40x80

$174,000

median across 28 projects

Read that attribution carefully. Steel Structures America operates across Idaho, Washington, Oregon, Colorado and Montana — not Idaho Falls specifically. These are attributed regional medians, not local quotes, and a jurisdiction requiring a 47 psf ground snow load is not the cheapest place inside that footprint to build.

Shell-only, by size

For comparison against those finished medians, the same footprints as a standing shell — posts, trusses, roof and walls, no slab:

Shell-only estimate compared with finished median
SizeShell only, roughlyFinished median (SSA, regional)
30x40$18,000–$34,000$69,894
40x60$36,000–$67,000$119,721
40x80$48,000–$90,000$174,000

The two columns are not directly comparable — one is a shell estimate, the other a completed-project median from a different geography. Shown together, they map the distance your remaining budget has to cover.

Cost drivers, line by line

Typical effect on a 40x60 unless noted. These are market ranges, not a price list.

Post-frame shop cost drivers and typical effect
DriverTypical effect (40x60 unless noted)
Concrete slab, 4" with wire mesh$12,000–$20,000
Overhead doors, two standard$4,000–$8,000
Premium or oversized door, each$1,200–$5,500+
Insulation — batt $1.50–$3.00/sq ft, spray foam $3.00–$7.00+$10,000–$28,000
Site prep and excavation$3,000–$20,000+
Engineered stamped plans$1,500–$5,000
Snow-load engineering upgrade$1,580 documented single case; $5,000–$20,000+ per SSA
In-floor radiant heat$5,000–$25,000+
Plumbing and half-bath$5,000–$15,000+
Utility runs$5,000–$20,000+

Snow-load engineering carries two very different figures because the sources measure different things: $1,580 is one documented case of stepping a design from 60 psf to 75 psf with a 25% wind increase, including new sealed plans and truss drawings. The $5,000–$20,000+ range from Steel Structures America describes whole-building engineering for Idaho and Montana loads. Both explained in full →

What is not published

Three figures people ask for constantly have no published source. Rather than estimate them and put a number in your head that nobody stands behind, here they are as gaps.

  • Basalt excavation premium

    No source gives a dollar figure for the basalt premium on the Snake River Plain. Rock sits inside the published $3,000–$20,000+ site-prep range, undifferentiated.

  • Per-size door schedule

    No per-size overhead door price schedule was found for this market. Only the general ranges in the table above are published.

  • Post-in-ground vs concrete footing

    No figure exists for the cost delta between post-in-ground and a concrete-footing foundation. Any number you are given is a specific bid, not a market rate.

If a page quotes you a confident number for any of those three, ask where it came from. The honest answer for this market is that it is not published, and the way to get a real figure is a bid on your actual parcel.

Cost questions

Why is the kit price so far below the bid?
They cover different scopes. A materials package runs $8–$18 per square foot and is lumber, steel and fasteners on the ground. A finished shop runs $30–$60 per square foot and includes the slab, doors, power, insulation and labour. Neither number is wrong; they are answers to different questions, and most sticker shock comes from comparing one to the other.
What does a 40x60 cost here?
Steel Structures America publishes a $119,721 median across 140 completed 40x60 projects. That is a regional figure covering Idaho, Washington, Oregon, Colorado and Montana, not an Idaho Falls quote. Shell-only for the same footprint runs roughly $36,000–$67,000. Where a specific project lands inside that spread is set by slab, doors, insulation, site prep and the adopted snow load.
Is there a published premium for hitting basalt?
No. No source publishes a dollar figure for basalt excavation premium on the Snake River Plain. Site prep as a whole is published at $3,000–$20,000 or more, and rock sits inside that range, but any per-yard or per-hole rock number you are quoted is a bid from a specific contractor rather than a published market figure. Ask for it in writing before excavation starts.

Turn the ranges into a number for your lot

Send the address, the size and what you plan to keep in it. You'll get the scope level those figures assume, the design load that applies, and what the ground is likely to add.

No obligation. Your request goes to an independent local builder.

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