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30×40 Barndominium Shell Cost in Idaho (2026)

A 30×40 barndominium shell in Idaho has a dried-in shell estimate of about $66,261 in 2026 ($55.22 per sq. ft.). Here's the itemized breakdown of materials, site prep and labor, using local crew rates.

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Shell Materials Kit

$28,184

Frame, trusses, steel, windows, doors & spray foam

= Rows 3–8 below, materials only

Slab, Plumbing Sleeves & Site Prep

$11,959

Grading, under-slab plumbing sleeves & reinforced slab

= Rows 1–2 below, installed price

Dried-in Shell Estimate

$66,261

$55.22 per sq. ft.

Dried-in shell built by a local licensed crew

= All rows below, installed price

A fair bid from a local builder in Idaho should land between $60,960 and $72,887. Get 3 quotes, and if one is far outside this range, ask why.

Estimate only. Actual prices vary. No guarantee or warranty. Use as a guide only. Read the full disclaimer

Itemized cost breakdown

#	Item	Quantity	Materials	Labor	Installed
1	Site grading & building padLaser-leveled pad 2 ft past the walls, compacted fill	1,496 sq ft	$664	$960	$1,949
2	4" standard concrete slab + plumbing sleeves3,500 PSI ready-mix, #4 rebar 18" grid, vapor barrier, forms	15.9 cu yd	$4,800	$3,542	$10,010
3	6×6 treated posts, girts & framing lumber18 posts × 16 ft (.60 CCA ground-contact), 2×6 girts, 2×8 treated skirt board	18 posts + 980 lf	$4,640	$4,802	$11,330
4	30' engineered roof trusses & purlins21 trusses at 2 ft on center, 115 mph rated, 2×4 purlins	21 trusses + 630 lf	$6,638	$2,881	$11,423
5	29-ga metal roof & wall panels + trimPainted steel panels, ridge cap, corner/door/base trim, closures	31.5 squares	$4,342	$1,931	$7,528
6	Doors & windowsDetails in the spec sheet	🔒 Included in $19 spec sheet	$6,323	$1,974	$9,956
7	Closed-cell spray foam (roof & walls)Details in the spec sheet	🔒 Included in $19 spec sheet	$4,546	$1,969	$7,818
8	Screws, hardware & condensation barrierDetails in the spec sheet	🔒 Included in $19 spec sheet	$1,695	$384	$2,495
9	Permit, stamped drawings & deliveryDetails in the spec sheet	🔒 Included in $19 spec sheet	$3,127	$0	$3,752
	Dried-in shell estimate		$36,775	$18,443	$66,261

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Prices use 2026 material costs and typical local crew rates. Site work, custom options and material price swings can move your final price.

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Builder Spec Sheet & Shopping List

The same line items as this page in an editable Excel file and a PDF, each with a short spec, quantity, materials, labor and installed price. Plus a permit and site-prep checklist and a sheet for comparing 3 builder bids. 30-day money-back guarantee.

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Common questions

How much does a 30×40 Barndominium Shell cost in Idaho?

About $66,261 for a dried-in shell (structure, roof, walls and doors), built by a local crew. Interior finish, utilities and site work are not included. Roughly $28,184 for the materials kit alone. Most fair bids land between $60,960 and $72,887.

What drives the price up or down?

Site prep (slope, soil, driveway access), floor choice, doors and insulation, and local labor rates. Lumber and steel prices also move a few percent a year.

Do I need a permit?

Most counties require a building permit for structures over 200 sq ft. Call your county building department with your size and location before you order materials.

How do I make sure I'm getting a fair quote?

Get at least 3 itemized bids for the same spec. Compare them line by line against this breakdown and ask about anything far above or below it.