Now it’s time to figure out what size of metal building you need and approximately how much it will cost.
The size of your building will impact two main costs:
The price of the metal building itself (which includes installation).
The cost of the foundation required to support your metal building.
Most metal buildings are installed on a concrete slab. If you don’t have a concrete foundation yet, don’t worry. Later in this guide, I’ll cover everything you need to know about metal building foundations. For now, I’ve included a chart that estimates the average cost of a concrete slab based on different building sizes. This will help you get a rough idea of what size metal building fits within your budget.
Use the following chart to get an idea of what size of metal building is right for you:
| Size | Dimensions | Garage Cost | Concrete Slab | Area |
|---|---|---|---|---|
| Small one-car garage | 12′ x 20′ | $4,500+ | $2,000+ | 240 sq. ft. |
| Large one-car garage with workspace | 18′ x 25′ | $5,500+ | $4,000+ | 450 sq. ft. |
| Small two-car garage | 20′ x 20′ | $6,500+ | $3,500+ | 400 sq. ft. |
| Large two-car garage | 24′ x 25′ | $8,000+ | $5,000+ | 600 sq. ft. |
| Large two-car garage with workspace | 24′ x 30′ | $9,000+ | $6,000+ | 720 sq. ft. |
| Three-car garage (doors on the side) | 24′ x 30′ | $10,000+ | $6,000+ | 720 sq. ft. |
| Two bay, four-car garage | 24 ‘x 40’ | $11,500+ | $8,000+ | 960 sq. ft. |
Planning a Custom Metal Building
To determine the ideal dimensions, consider sketching a floor plan. This will help you visualize how your vehicles will fit inside and how much space remains for storage or a workspace.
If you decide to sketch a layout, keep in mind that the interior dimensions of your metal building will be about half an inch smaller than the exterior measurements. This is because the standard 14-gauge framing used in metal buildings is 2 ½ inches thick.
Measure Your Vehicles
- Use a tape measure (this is easiest with two people).
- Extend both arms next to your car—your fingertip span is roughly your height.
- Use the vehicle size chart below.
Determine Your Metal Building Width
- Start with your vehicle widths and leave at least 3 feet of clearance on each side for easy door access.
- Ensure 3 feet of space between vehicles for comfortable movement.
- If you need additional storage, add that to your total width.
Don’t forget: The building frame adds about ½ foot per side, so include that in your calculations.
Example: 3 feet of clearance + a 6.5-foot-wide truck + 3 feet of space + a 6-foot-wide car + 3 more feet of clearance + 2 feet for storage + approximately 0.5 feet for the frame = a 24-foot-wide metal building.
Calculate Your Metal Building Length
- Add 1 foot to each end of your longest vehicle.
- Include extra space for storage or a workspace.
Example: 1 foot of clearance + a 19.5-foot-long truck + 1 more foot of clearance + 8 feet for a work area + approximately 0.5 feet for the frame = a 30-foot-deep metal building.
For cost efficiency, try to keep at least one dimension under 30 feet—larger buildings require more materials and increase costs. A 32’x32’ metal building will be more expensive than a 30’x35’, even if both have the same square footage.
| Vehicle Type | Width | Length | Height |
|---|---|---|---|
| Sports Car | 5′ ½ – 6′ ½ | 13′ – 16′ | 4′ – 4′ ½ |
| Compact Car | 6′ | 14′ – 15′ | 5′ |
| Mid-Size Car | 6′ | 15′ – 16′ | 5′ |
| Full-Size Car | 6′ | 16′ – 17′ | 5′ |
| Minivan or SUV | 6′ ½ | 16′ – 17′ | 5′ ½ – 6′ ½ |
| Full-Size Truck | 6′ ½ | 17′ – 22′ | 6′ ½ |
| Class A RV | 8′ ½ | 29′ – 45′ | 5′ ½ – 6′ ½ |
| Class B Camper Van | 8′ | 17′ – 23′ | 9′ – 11′ |
| Class C RV | 8′ – 8′ ½ | 21′ – 41′ | 10′ – 12′ |
* Widths do not include the width of rear-view mirrors.
In the next chapter, you’ll learn how to use an online metal building designer to plan and price your structure.
