Quick Answer: A 20x40 metal building (800 sq ft) typically runs $14,500–$17,000 kit-only (~$19.72/sq ft) or $20,100–$23,600 fully installed turnkey (~$27.31/sq ft). Get your free quote for the exact number on your site.
At 800 square feet, a 20x40 metal building is one of the easiest sizes to fit onto a typical residential lot — it sits comfortably beside a house or along a side yard without tripping the setback or lot-coverage limits that bigger structures can run into. Because it's small enough to qualify as an accessory structure in most jurisdictions, permitting is usually faster than it is for a full-size shop or barndominium shell, which makes a 20x40 a practical first metal building for a lot of homeowners.
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20x40 Price Breakdown
| Cost Component | Estimate |
|---|---|
| Kit only (DIY) | $14,500–$17,000 total (~$19.72/sq ft avg) |
| Turnkey (installed) | $20,100–$23,600 total (~$27.31/sq ft avg) |
| Concrete foundation add-on | ~$4,000 |
| Professional labor add-on | $3–$5/sq ft |
These figures reflect current published industry benchmarks for this size, positioned at our wholesale rate — get a quote for pricing specific to your location.
Need a size that isn't listed here? Run your own numbers with the metal building cost calculator, or see how this compares in our full cost-per-square-foot guide.
Popular Uses for a 20x40 Metal Building
An 800-square-foot footprint is enough for a genuinely usable space without becoming a major building project, which is why this size shows up so often as a first metal building:
- Single-car garage with room to spare — enough depth for a full-size vehicle plus a workbench or tool wall; see our garage kit options for layout ideas
- Standalone workshop or hobby shop — woodworking, small-engine repair, or a maker space separate from the house
- Backyard studio or home office — a quiet, detached workspace that doesn't eat into living-area square footage
- Lawn and garden equipment storage — mowers, tractors, and seasonal gear kept out of the weather
- Overflow storage for a home-based business — inventory, supplies, or equipment that's outgrown the garage
- Single-vehicle or small boat storage — a straightforward, secure alternative to an off-site storage unit
See the full size index for every available size if 20x40 isn't quite the right fit.
What's Included
Kit-only pricing on a 20x40 building covers the primary steel frame, roof and wall panels, one walk door, one drive-in door, engineering stamps for your local building code, and delivery to your site. It's everything you need to erect the structure yourself or hand off to a local contractor.
Turnkey pricing builds on that base by adding the concrete foundation, professional erection and labor, and permit coordination — so the building shows up essentially finished and ready to use rather than as a kit waiting to be assembled.
Not included at either level: insulation, interior finish-out, custom colors, additional windows beyond the standard package, and electrical or plumbing rough-in. See insulation options and finishing options for what those typically add to a 20x40.
What Affects Your Price
- Foundation type — a standard 4"-6" slab is the most economical option; reinforced foundations for soft or expansive soil cost more
- Region — labor rates, material shipping, and local code requirements vary by state; check your state page for specifics
- Finishing level — insulation, interior walls, and custom exterior colors are priced on top of the base structure
- Door and window count — the standard kit includes one walk door and one drive-in door; adding more of either raises the total
Foundation Requirements for a 20x40
A 20x40 building typically sits on a standard 4"-6" concrete slab, estimated at around $4,000 for this footprint. That number assumes reasonably stable soil and a site that doesn't need significant regrading before the pour.
- Soil conditions — soft, sandy, or expansive soil may call for additional reinforcement or a deeper footing
- Site prep — clearing, grading, or drainage work is priced separately from the slab itself
- Frost line depth — colder climates often require footings below the frost line, which adds material and labor cost
See foundation options for a full comparison of slab types and when each makes sense.
Common Mistakes to Avoid
| Mistake | Why It Costs You | Fix |
|---|---|---|
| Comparing a kit-only quote here to someone else's turnkey number | Turnkey includes foundation and labor, so the two prices aren't measuring the same thing | Confirm whether every quote you're comparing is kit-only or fully installed |
| Sizing down to 20x40 purely to hit a lower sticker price | A too-small building often gets outgrown within a few years, and building again later costs more than sizing right the first time | Size for how you'll actually use the space, not just the lowest quoted number |
| Skipping a soil or site assessment before ordering | Unexpected soil conditions can add foundation cost after your budget is already set | Get a basic site or soil check before finalizing your foundation estimate |
| Waiting to decide on finishing options until after the building is up | Retrofitting insulation or interior finish-out costs more than specifying it at the time of your quote | Decide on your finishing level before your building ships |
Get Your Exact 20x40 Price
We've shipped more than 14,000 kits backed by 50-year structural warranties, all at wholesale pricing. Getting your exact number for a 20x40 building — priced for your location, foundation, and finish level — takes just a few minutes. Get your free, no-obligation quote.
FAQ
How much does a 20x40 metal building cost?
Kit-only pricing for a 20x40 (800 sq ft) building typically runs $14,500–$17,000, or about $19.72 per square foot. A turnkey, fully installed building typically runs $20,100–$23,600, or about $27.31 per square foot, before finishing options.
What can I fit in a 20x40 building?
A 20x40 comfortably fits a single-car garage with workbench space, a standalone workshop, a backyard studio or home office, lawn and garden equipment storage, overflow storage for a home business, or a single vehicle or small boat.
Do I need a permit for a 20x40 metal building?
In most areas, yes, though requirements vary widely by jurisdiction and lot size. Check your state page for local permitting guidance before you finalize your order.
Is a 20x40 metal building hard to construct myself?
It's one of the more manageable DIY sizes — the footprint is small enough for an experienced crew to erect without heavy equipment. That said, most owners still bring in a local contractor for the concrete work and final assembly rather than doing the entire project solo.
What size foundation does a 20x40 building need?
A standard 4"-6" concrete slab sized to the building's 800 sq ft footprint, estimated at around $4,000 depending on soil conditions and site prep.
Can I finance a 20x40 metal building?
Yes. See financing options and rent-to-own for ways to spread out the cost instead of paying in full upfront.
How do I get an exact price for my 20x40 building?
The fastest way is a free custom quote, since pricing depends on your exact location, foundation choice, and finish level.
Get your free, no-obligation quote.
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