Farm Buildings: Sizes, Costs and Which Type Fits

Farm Buildings: Sizes, Costs and the Right Type for the Job

Farm buildings are metal post-frame structures: columns carry the trusses, the trusses carry the roof, and the steel skin does the rest. The same frame covers a cattle barn, a machine shed, a hay barn or a roof-only run-in — what changes from one to the next is how much of that frame gets walls, doors and a slab, not the frame itself.

This page is the hub for every agricultural building guide on this site. It prices farm buildings by footprint, works through the enclosed-versus-open decision that actually drives the cost, and sorts eleven pages by what they hold — equipment, cattle, horses or hay — so the guide worth reading is one click away. Where a use has a page of its own, it is linked below rather than repeated here.

None of the eleven guides below is a different product. Every one of these farm buildings ships as the same post-frame kit, priced the same way by floor area. What separates a machine shed from a loafing shed is how much wall and door goes on that kit, and that is a decision this page can help make before a supplier ever gets involved.

What a Farm Building Actually Is

A farm building is built by post-frame methods. Widely spaced columns go into the ground or onto brackets set in concrete, girts and trusses tie them together, and the steel skin hangs on the outside. There is no continuous perimeter footing and no load-bearing stud wall doing structural work. The floor inside stays clear from wall to wall — the whole reason this shape works for a machine shed one year and a different machine the next.

The Metal Building Manufacturers Association notes that metal building systems can span great widths and lengths with or without additional interior supports, and that clear span is the whole argument for building farm buildings this way. A sixty-foot-wide floor with nothing in it holds a combine one season and a herd the next, with nothing in the middle to move around.

The same association points out that metal buildings are governed by the same building codes and material standards as other forms of construction. An agricultural building or an agricultural steel building on this site is engineered to the same wind, snow and seismic loads as a house down the road; the difference is in the occupancy, not in the frame. The International Code Council publishes the model building codes that more than 21,000 U.S. jurisdictions enforce, and which edition is in force locally is a question for the building department, not a number worth guessing at.

That is the whole category, in one shape. Eleven farm buildings below are variations on it: the same columns, the same trusses, the same steel, with the wall count, the door count and the floor changed to match a machine, a herd or a stack of hay.

Every Agricultural Building Guide Here

Eleven agricultural building guides sit under this hub. Each answers a different question, and the fastest way through is to find the row that matches what the building actually has to hold.

The roof-only cover and the open pole barn answer the same question from opposite ends of the same scale — how much of the frame gets walls — and each links the other. That question, enclosed or open and how big, is the one every one of these farm buildings has to answer, and it is the one this page works through next.

Enclosed or Open, and How Big

This is the real decision, and it comes before the footprint. A roof on posts stops sun, hail and most rain. Walls and doors stop wind-driven rain, dust, theft and a curious animal getting somewhere it shouldn't. Everything else about farm buildings on this page follows from that one choice.

An open structure is cheaper per square foot because there is less of it: fewer panels, no overhead doors, no insulation, and often no slab if the floor is gravel or packed earth. A small open cover can also sidestep work an enclosed building cannot. Shallow footings must extend below the frost line under the model building code, but free-standing buildings with an area of 400 square feet or less and an eave height of 10 feet or less are excepted from that. A loafing shed or a small roof-only bay can fall inside that exception; a sixty-by-hundred machine shed never will.

Size farm buildings from what they hold outward, not from a round number inward. The table below is the same one this page prices in the next section, so the footprint picked here is the one that gets costed out immediately after.

Add depth before width when a size sits between two rows. The extra ten feet that turns 40×60 into 40×70 is cheaper square footage than moving up to the next size. It is usually what makes room for the workbench, the extra stalls or the trailer nobody sized for at the start.

What a Farm Building Costs

Kits are quoted per square foot of floor, and the rate depends on size: $13–$25 under 600 square feet, $9–$32 from 600 to 1,500, $7–$24 from 1,500 to 3,000, and $7–$22 over 3,000. The kit range for any of these farm buildings, at any of the five sizes below, comes from multiplying its own rate by its own footprint.

The kit is not the building. Here is the same 40×60, taken to a weather-tight, standing shell.

For farm buildings at this size, that is $45,000–$123,900 installed, or about $19 to $52 per square foot. An open cover of the same footprint skips the slab and the doors and comes in lower; ask a supplier to price it both ways before deciding, since the gap is bigger than most people expect.

Framing and finish are the other lever. Red iron framing costs more than a light truss frame, taller eaves add roughly 3% per foot of eave height, and more or larger doors, stamped drawings for a heavy snow or hurricane rating, painted panels and insulation all push a quote toward the top of the range. Most farm buildings on a working operation sit lower in the range — light framing and bare panels where the building is unheated storage and nobody will look at it twice, heavier framing and painted panels where the building faces the road or holds something that cannot get wet.

Storage and Equipment Buildings

Three of these farm buildings hold equipment and nothing else, and the difference between them is scale. A machine shed is sized to the largest thing that has to fit through the door — a combine, a header on a trailer, a sprayer with the booms folded — so door height and drive-through bays come before anything else. Whatever an agricultural building kit ends up costing, get the door opening right first; nothing else on this page matters if the machine will not fit through it.

A tractor barn is the same idea at a smaller scale: one or two tractors and their implements. One end or one side is often left open, so a wagon or a mower can pull straight through without a door to open first. A pole barn shed is neither of those — it is the small, general-purpose farm shed on this site, priced to be the cheapest square footage available. It is not meant to hold a machine at all.

All three are the same post-frame kit at a different size: an agricultural steel building with the wall and door count matched to what has to go inside. A prefab agricultural building shipped as a kit still needs the same slab, erection and site work priced above — the kit price is a floor under the finished cost, not the finished cost itself. Farm buildings bought as storage, in particular, are the easiest place to save: an unheated, uninsulated shell with light framing and bare panels is usually enough for anything that isn't a running engine or a living animal.

Livestock Buildings

The other three of these farm buildings hold animals, and each is built for a different amount of shelter. A cattle barn is enclosed: housing, a calving area, a working chute and hay storage under one roof, built where winters or the operation call for it. Cattle sheds are lighter — open-fronted, mono-slope, three sides over a bedded pack or a lot, built where animals need shade and a dry bed more than four walls. A loafing shed is the smallest of the three: a run-in in the pasture, two or three sides, sized for a handful of head or a couple of horses rather than a herd.

Whichever of the three, ventilation matters more than insulation. Penn State Extension’s guidance for naturally ventilated barns is built around a ridge opening that lets warm, moist air flow up and out. Fresh air comes back in through continuous sidewall openings at the top of both sidewalls equal to one-half of the ridge opening, without a direct draft on the animals. A sealed, unventilated building traps moisture and ammonia; an open-fronted shed or a barn with a working ridge vent does not.

None of that changes the frame underneath. Livestock farm buildings are the same post-frame kit as the storage buildings above, with a different amount of wall on them, priced the same way as everything else on this page: by footprint, at the rate chosen for it.

Doors, Ventilation and the Floor

Door height is set by what drives through it, not by habit. A tractor with a loader up clears eight or nine feet; a combine with the header off can still want twelve; a stock trailer wants width more than height. Measure the tallest, widest thing that will ever need to get inside, add a foot for clearance, and set the door to that number rather than to what looks right on a drawing. Every one of these farm buildings answers that question differently, but the method of measuring it is the same.

Roof vents do real work on any farm building, not only a livestock one. The same chimney effect that pulls moist air out of a cattle barn also clears heat and exhaust out of an equipment bay, and a continuous ridge vent costs little next to the kit itself. If any part of the building will be heated — a work bay, a small office in the corner — the insulation follows the commercial energy code rather than the residential one. The Department of Energy's COMcheck is the free tool that checks whether a building like this one complies.

A slab is not structural for a post-frame building — the columns carry the load, which is why an open cover can sit on gravel. But anything with a piece of equipment or a stall in it wants a poured floor: gravel holds moisture against hooves and tires, and a slab is what keeps a shop floor level under a jack. Decide the floor at the same time as the walls, not after the kit has already shipped.

Paying for a Farm Building

Most farm buildings on this site are bought one of three ways. An operation with an existing relationship at a farm credit lender or a local ag bank often rolls the building into the same loan that covers equipment or land, since the lender already understands the operation's cash flow. An owner with equity in the property can instead borrow against that equity directly. And many kit sellers offer financing on the kit itself, separate from the site work and the slab — worth asking about before shopping a bank loan alone.

Whichever route is used for farm buildings like these, get quotes on the exact footprint and options before applying for anything. A lender or a farm credit officer asking what the building will cost deserves a number from a real quote, not a guess extrapolated from a neighbor's barn.

From Quote to Building

Whichever of these farm buildings fits, the stages run in the same order at any size on this page.

1. Settle the use, the footprint and whether it is enclosed or open, then get quotes from up to five suppliers.
2. Pull the permit and confirm setbacks with the local building department.
3. Excavate and pour the slab, or set piers, to the local frost depth.
4. Erect the columns, trusses and skin.
5. Hang the doors and grade or pour the apron.
6. Run electrical if the building needs it, and finish out any work bay.
7. Final inspection, then occupancy.

The permit and the concrete cure are usually the longest waits on that list, not the steel. A kit goes up in days once the crew is on site; the paperwork ahead of it rarely does.

The building is straightforward; the decisions are not. Enclosed or open sets the base cost, footprint sets the kit price, and what will live inside sets the door height and the floor. Everything else about farm buildings can be adjusted later — the apron, the extra outlet, the second coat of paint — and those three cannot.

So settle what the building has to hold, put a number against the footprint from the tables above, and have suppliers price that exact building. Farm buildings priced by several suppliers are the only way to know what a footprint costs where you farm.

Related Resources

• Loafing Shed
• Cattle Barn
• Machine Sheds
• Tractor Barns
• Roof-Only Pole Barn
• Pole Barn Cost Estimator
• 3D Pole Barn Designer