The Cost of a 30×40 Metal Building with a Concrete Slab in 2026

A 30×40 building gives you about 1,200 square feet of space, which is why this size shows up so often on residential properties, small farms, and hobby workshops. It’s big enough for several vehicles or equipment, but not so large that the project turns into a full commercial build. The total cost usually comes down to two main pieces: the building kit itself and the slab underneath it. Once those two are figured out, the rest of the budget mostly comes from upgrades, site work, or local requirements. Below is a realistic look at what buyers often pay for three common versions of this building size: a garage, a carport, and a barn. Typical Cost for a 30×40 Metal Building with a Concrete Slab At 30 feet wide and 40 feet long, you’re dealing with 1,200 square feet of coverage. That’s enough room for multiple vehicles, a decent shop area, or a mix of storage and workspace. Your total cost will include: The steel building package The concrete slab foundation Any upgrades or add-ons Site preparation Permits or local engineering requirements The structure you choose makes a big difference in the price. Garages cost more because they’re fully enclosed. Carports cost less because they’re open. Barn-style buildings fall somewhere in between, depending on the layout. The concrete slab itself is fairly consistent across all three options. For a 30×40 slab, many projects land somewhere around: Low end: $4,800 Common range: $6,000 to $9,600 Higher-end installs: $10,000 to $14,400+ That range shifts depending on thickness, reinforcement, grading, and local labor costs. 30×40 Metal Garage Cost with Concrete Slab For homeowners who want a fully enclosed structure, a metal garage is usually the go-to option. A building this size works well for things like: Parking multiple vehicles Storing trucks or SUVs Lawn equipment and tools ATVs or motorcycles Hobby workshops Small business storage Because the structure is enclosed on all sides, garages require more material than open buildings. You’re adding wall panels, framing around door openings, and usually at least one large garage door. Estimated Price for the Garage Structure A basic 30×40 metal garage generally starts around: $18,000 to $28,000 Once you start adding upgrades like vertical roofing, multiple garage doors, walk-in doors, windows, or heavier framing, the cost often moves into the range of: $28,000 to $40,000 or more Customization is what changes the price the most. Concrete Slab Cost The slab underneath a garage usually falls into the same range seen with other buildings: $4,800 to $14,400 Most projects land closer to: $6,000 to $9,600 The final cost depends on slab thickness, reinforcement, and site prep. Total Cost: 30×40 Garage with Slab When both pieces are added together, a realistic planning range looks like this: Basic project: $24,000 to $34,000 Moderately upgraded build: $32,000 to $45,00 0 Heavily customized garages: $45,000+ Why Garages End Up Costing More It re