30x40 prices by wall height

A 30 × 40 ft building covers 1,200 sq ft. Delivered and installed in tube steel with three 10 × 10 ft roll-ups, one walk door, it lists for $17,600–$48,400 with 12 ft walls. On a 4 in slab the total comes to $22,400–$58,000.

With the footprint fixed, the wall height moves the price most: every foot adds steel to all four walls, and a taller wall takes a taller door. The table keeps three roll-ups on the 40 ft side wall and changes the walls; a wall too low for the doors gets the tallest door it takes. Prices were read Oct 30, 2026; each range holds the middle 80% of what sellers publish for a comparable building. Pick a height to open it in the designer above.

Wall height	Peak	Price, installed	With a 4 in slab
10 ft wallsthree 9 × 8 ft roll-ups, one walk door	13 ft 9 in	$16,500–$45,500	$21,300–$55,100
12 ft wallsthree 10 × 10 ft roll-ups, one walk door	15 ft 9 in	$17,600–$48,400	$22,400–$58,000
14 ft wallsthree 10 × 10 ft roll-ups, one walk door	17 ft 9 in	$18,600–$51,300	$23,400–$60,900
16 ft wallsthree 10 × 10 ft roll-ups, one walk door	19 ft 9 in	$19,700–$54,200	$24,500–$63,800

The peak is the height at the ridge. The roll-up doors sit in the walls, under the eave, so the wall height, not the peak, sets how tall a door the building takes.

Kit, installed or post frame

The ranges above are for a finished building: the dealer’s crew sets it on your level site and the doors come in it. The same footprint is sold two other ways, and both prices leave out work that the installed price already holds:

Steel kit: $15,700–$29,400. Kit only: frame, panels, trim and stamped drawings. Delivery, erection, doors and slab extra. The frames in these listings are red-iron I-beams or lighter cold-formed and open-web steel.
Post frame: $18,500–$33,800. Materials kit, usually delivered. Labor and slab extra. Wood posts set in the ground carry the steel panels.

So compare like with like: a kit plus a crew, doors and delivery against an installed building, not the kit price alone.

These are ranges of published list prices, not quotes. Delivery distance, the steel gauge, permits and options such as insulation change what a dealer quotes.

Slab and concrete for a 30x40

A 4 in slab under a 30 × 40 ft building takes 20 cu yd of concrete. That covers the full footprint, a thickened edge under the walls, and extra for spillage and an uneven base: 4 in slab, 12 in thickened edge, 10% extra. Installed, it runs $4,800–$9,600.

A 6 in slab, for heavier loads on the floor such as a car lift or equipment, takes 29 cu yd and runs $7,200–$12,000. At this size it is a ready-mix truck, not a bag job: the designer gives the yards to order, rounded up, and a bag count only for a small pour.

The slab cost is a per-square-foot range from the cost guides of Angi, HomeGuide and This Old House: $4 to $8 per square foot for 4 in. The range is for the slab itself; a site that needs grading or fill, or a pump to reach it, costs more.

The code sets the floor. The International Residential Code gives a minimum thickness for a concrete floor on the ground (section R506.1), and a 4 in slab is above it. Where the ground freezes, the footing under the walls goes below the frost depth your building department sets.

The thickened edge in the concrete count is a planning allowance, not a footing design: its depth is local, and a red-iron building’s piers and anchor bolts come from its engineer.

How many cars fit in a 30x40

With three roll-up doors on the 40 ft side wall, 3 pickups park side by side, each in its own lane. The building is 30 ft deep from those doors, room for a full-size pickup and a walkway behind it, so the designer above opens with its fit line reading “Fits three pickups.”

Each vehicle is drawn at the size its maker publishes and drives in nose first. The designer counts it as fitting only with:

6 in to spare on each side of the door and 6 in above it;
2 ft from a side wall and 3 ft from the next vehicle, so a car door can open;
1 ft from the entry wall, 2 ft between vehicles nose to tail and a 2 ft walkway behind the last one.

Which wall takes the doors changes the count more than anything else:

Cars, two deep. With the doors on the end wall, cars drive in along the 40 ft length and park nose to tail, as in the layout “Six cars” below.
A boat or a trailer. Two pickups and a boat on its trailer fit behind the side doors. A travel trailer is 10 ft 6 in tall: it needs a door at least 11 ft tall. With 14 ft walls and wider doors on the end wall, one parks beside a pickup.
RVs. An RV is 36 ft 11 in long: the building is 30 ft deep from the doors. Through the end wall it fits along the length, with 14 ft walls and one 12 × 14 ft roll-up, one walk door.

The sizes behind the drawing:

Vehicle sizes as each maker publishes them
Vehicle	Length	Width	Height
Pickup2026 Ford F-150	19 ft 4 in	6 ft 8 in	6 ft 5 in
Car2027 Toyota Camry	16 ft 1 in	6 ft	4 ft 9 in
SUV2027 Chevrolet Tahoe	17 ft 7 in	7 ft 10 in	6 ft 5 in
Boat on trailer2027 Yamaha AR205	21 ft 2 in	8 ft 6 in	6 ft 8 in
RV2027 Jayco Precept 34B	36 ft 11 in	8 ft 5 in	12 ft 10 in
Travel trailer2027 Jayco Jay Flight 260BH	29 ft 5 in	8 ft	10 ft 6 in
Compact tractorJohn Deere 1025R	9 ft	3 ft 11 in	7 ft 6 in
Riding mowerJohn Deere X350 (42-in. Deck)	6 ft	4 ft 3 in	3 ft 10 in
UTV2027 Can-Am Defender HD7	10 ft 1 in	5 ft 2 in	6 ft 4 in
Motorcycle2026 Honda Rebel 500	7 ft 3 in	2 ft 8 in	3 ft 7 in

Doors and floor layouts

The end wall of a 30 × 40 ft building is 30 ft wide and the side wall is 40 ft long. Which one takes the roll-up doors decides what parks inside:

Side wall. The long wall takes three full-size doors, one lane each, with the full depth of the building to park in. It suits pickups, SUVs and a boat on its trailer.
End wall. Vehicles drive in along the length and park two deep, but the short wall limits the doors: with three 9 × 8 ft roll-ups on it, the designer answers “The end wall is 30 ft; its doors take 27 ft and need at least 1 ft of wall beside each one.”
Walk door. The designer puts it on a wall without roll-ups, so you can get in without opening a big door.

Five layouts of this footprint, priced by the same model. Each opens in the designer, where you can move the doors, change the walls and add what you own:

Parked inside	Price, installed
Three pickups12 ft walls, three 10 × 10 ft roll-ups, one walk door	$17,600–$48,400
Six cars10 ft walls, three 8 × 8 ft roll-ups, one walk door	$16,500–$45,500
Two pickups and a boat12 ft walls, three 10 × 10 ft roll-ups, one walk door	$17,600–$48,400
A pickup and a travel trailer14 ft walls, two 12 × 12 ft roll-ups, one walk door	$17,200–$47,400
An RV14 ft walls, one 12 × 14 ft roll-up, one walk door	$15,800–$43,400

A 30x40 floor plan search often means a house plan as well as a garage. This page lays out where vehicles park and what floor is left for a bench, a lift or storage; the drawing answers it to scale, with your own vehicles in it.

These are planning drawings of where vehicles park, not construction plans or house plans. Door framing and openings come from the dealer’s drawings and your building department.

Snow load for your ZIP

Enter a ZIP code in the designer and it looks for weather stations within 25 km (16 miles) of it in the Utah State University snow-load data release (2023), CC BY 4.0. When the stations agree it shows one ground snow load; when they disagree it shows the range and names the nearest.

For a 30x40 the number goes to the dealer with the order: the frame and the roof are built for a stated load, and a building rated for a heavier one takes more steel and costs more. The price ranges on this page do not change with the load; a dealer’s quote does.

That is a planning value from a named dataset, not an engineer’s design. The building code sets the ground snow load for your site, and the building’s designer works out the roof load from it.

How the numbers are worked out

Price range

What it covers: A tube-steel building at the dealer’s list price, delivered and installed on your level site. The slab and site preparation are extra.
What moves it: The roof area, the wall area and the doors: a taller wall or one more roll-up door moves the range. The model behind it is fitted to 146 published prices from Alan's Factory Outlet, Carport Central and Get Carports.
Why it is wide: Sellers list the same building at very different prices, and the range holds the middle 80% of them. Where your quote lands depends on the seller, the steel and the options you add.
Where it stops: The data holds widths of 12 to 100 ft, lengths of 20 to 250 ft and walls of 6 to 20 ft. Steel kits and post-frame buildings are priced by their own models, from their own sellers.

Concrete and fit

The concrete is the slab’s volume plus the thickened edge and the extra, rounded up. The fit places each vehicle behind a roll-up door at the clearances above and reports the first thing that stops one: a door too narrow or too low, or no floor left.

Questions

How much does a 30x40 metal building cost?

$17,600–$48,400 for a 30 × 40 ft tube-steel building with 12 ft walls and three 10 × 10 ft roll-ups, one walk door, delivered and installed. With 10 ft walls it lists for $16,500–$45,500, and with 16 ft walls for $19,700–$54,200. A steel kit of the same size lists for $15,700–$29,400 before delivery, erection and doors.

How much would a 30x40 slab cost?

$4,800–$9,600 for a 4 in slab, installed, and $7,200–$12,000 for 6 in. It takes 20 cu yd of concrete at 4 in and 29 cu yd at 6 in, with a thickened edge under the walls. With the building on top, the total comes to $22,400–$58,000.

How many cars will a 30x40 garage hold?

3 pickups or 3 cars with three roll-up doors on the side wall, one per lane. With the doors on the end wall, cars park two deep: the layout “Six cars” has 10 ft walls and three 8 × 8 ft roll-ups, one walk door.

Is it cheaper to build a pole barn or buy a metal building?

On materials alone, often the kit: for a 30 × 40 ft building a post-frame kit lists for $18,500–$33,800 and a steel kit for $15,700–$29,400, with labor extra in both. A tube-steel building delivered and installed lists for $17,600–$48,400, with the crew in the price. Get the crew’s price for a kit before comparing it with an installed building.

How thick of a concrete slab do I need for a metal building?

For a garage or a shop, 4 in is the common slab, and it is above the code minimum for a concrete floor on the ground (International Residential Code, R506.1). Under a 30 × 40 ft building it takes 20 cu yd. For a lift or heavy equipment, a 6 in slab takes 29 cu yd. A red-iron building’s engineer sets the piers and anchor bolts, which can ask for more under the frame.

Sources

Building prices: 146 published prices of tube-steel buildings from Alan's Factory Outlet, Carport Central and Get Carports, read Oct 30, 2026. Steel kits: published prices from Armstrong Steel, QE Building Co., Simpson Steel Building Company, Sunward Steel and Worldwide Steel Buildings. Post frame: FBi Buildings and Hansen Pole Buildings.
Slab cost: concrete slab cost guides by Angi, HomeGuide and This Old House.
Snow loads: Wagstaff, Wheeler, Bean, Maguire and Sun (2023), Supplementary Files for "Adaptive Mapping of Design Ground Snow Loads in the Conterminous United States". Utah State University snow-load data release (2023), CC BY 4.0.
Vehicle sizes: the makers’ published specifications for the models in the table above.
2024 International Residential Code, chapter 5 (floors), section R506.1: the minimum thickness of a concrete floor on the ground.
2024 International Residential Code, chapter 4 (foundations): footings and the frost depth.
FEMA P-957, Snow Load Safety Guide (January 2013), section 2.1: how the code’s ground snow load becomes the design load on a roof.

30x40 metal building: price, slab cost and layouts

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