Post spacing, trusses, girts, purlins and metal panels for a post-frame barn.
Estimates are planning aids, not a professional quote. Double-check quantities and product coverage — and any local code or permit requirements — before you buy.
⚠ Post-frame buildings still virtually always need a permit and engineered truss drawings, even without a continuous foundation. Confirm frost-depth post embedment and snow/wind loads with your local building department before ordering.
| Lumber & Decking | $3,101–$4,196 |
| Siding & Trim | $1,586–$2,146 |
| Roofing | $1,435–$1,941 |
| Posts & Panels | $1,371–$1,855 |
| Doors & Windows | $989–$1,337 |
| Fasteners & Hardware | $694–$938 |
| Concrete & Footings | $321–$435 |
| Connectors & Brackets | $92–$124 |
| Total | $9,588–$12,972 |
Excludes tools, delivery, tax and permit fees. Labor not included — this is a DIY materials estimate.
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About this calculator
Give the Pole Barn Builder a footprint, eave height and post spacing and it produces a full post-frame takeoff: embedded 6×6 posts and their footing concrete, clear-span trusses, girts and purlins on the flat, metal roof and wall panels with ridge cap and trim, a sliding bay door, a walk door and windows — plus every fastener, tools, a cost range and a build time.
Post-frame construction skips the continuous foundation wall a stick-framed garage needs — the posts themselves carry the building, set deep in the ground with a concrete footing pad at the base of each hole. Open advanced options for embedment depth, door sizing, an optional floor slab and waste.
Step by step
A step-by-step walkthrough to go with your plan above. Follow the product instructions and any local code or permit requirements as you work.
String the perimeter, square it by checking diagonals, and mark every post location at your chosen spacing. Auger each hole to the full embedment depth plus a few inches for the footing pour.
Stand each post, brace it plumb in both directions, and hold every post top to one level plane with a laser or transit — this is what the trusses and every panel course will reference.
Pour concrete around and under the base of each post while it's still braced plumb, then backfill and tamp the rest of the hole in lifts. Let the concrete set before loading the posts with trusses.
Lift the clear-span trusses onto the post tops at your spacing, brace them temporarily, then tie each one down with post-to-truss saddle brackets before removing the braces.
Run the horizontal 2×6 girts across the posts up each wall, and the 2×4 purlins across the trusses up the roof, both at 2-foot spacing on the flat. These are what the metal panels screw to.
Sheet the roof with metal panels from eave to ridge, overlapping each panel per the manufacturer's spec, then cap the ridge. Getting the roof dry lets you work the walls in any weather.
Install metal wall panels vertically over the girts, working around the door and window openings, then trim the corners, eaves and rakes with coil trim.
Mount the sliding door track and hangers to the header, hang the door panel, then set the walk door and windows. Caulk and flash every opening before calling for inspection.
Equip the job
Hand-picked categories that match the shopping list above. Links open a current selection so you can compare brands and prices.
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Keep planning
Decks & Structures
Answers
A pole barn (post-frame building) is carried by large posts — usually 6×6 pressure-treated lumber — set directly into the ground and often footed with a concrete pad at the bottom of each hole. A stick-framed garage instead sits on a continuous concrete foundation or slab, with short studs framing the walls on top of it. Post-frame skips the perimeter foundation entirely, which is why it's faster and cheaper to build at large clear spans, especially for barns, shops and equipment storage.
Most residential post-frame buildings set posts 4 to 5 feet deep, with the exact depth driven by your local frost line and the eave height — taller buildings put more leverage on each post and need deeper embedment or a wider footing pad to resist overturning. Codes in cold climates often require posts below the frost depth regardless of building height. Check with your local building department before digging; this calculator uses a conservative default, not an engineered value for your site.
Not necessarily. Many pole barns built for hay, equipment or general storage are left with a compacted gravel or dirt floor, which is cheaper and drains well. Add a slab if you plan to use the building as a shop, want to park and wash a vehicle inside, or need a clean, level surface for benches and shelving. The calculator adds a 4-inch floating slab with a gravel base and vapor barrier when you switch the floor option on.
Size it to whatever needs to pass through, plus a couple feet of clearance — a compact tractor typically wants at least a 10-foot opening, while a combine or an RV can need 14 to 16 feet or more. Wider openings need a heavier track and more support framing around the header, which the hardware kit cost scales with. Measure your widest piece of equipment with mirrors or attachments extended before you lock in a width.
Almost always, yes, even though there's no continuous foundation. Building departments still require a permit, a site plan, and increasingly, engineered (stamped) truss and post-embedment drawings sized to your snow and wind load. Agricultural exemptions exist in some jurisdictions for true farm-use buildings, but adding electrical, plumbing, or living space almost always pulls the building back under full code. Confirm before you start digging.
Metal panels span farther between supports than shingles or lap siding need, so post-frame purlins and girts can sit at wider spacing than conventional rafters and studs — that's a big part of why post-frame construction goes up fast. Metal panels also shed snow well, last 30-plus years with minimal maintenance, and are simple to fasten with washered screws driven straight through into the framing below, which this calculator accounts for in the fastener count.