Metal Carports: Prices by Size, Roof Styles & What Certified Means

A metal carport is the cheapest permanent cover you can put over a vehicle, and it is also the product most often bought wrong. Not because buyers pick the wrong size — because almost nobody explains the two decisions that actually matter, and both of them are invisible on a price sheet.

The first is whether your unit is certified. The second is what your own address requires for wind and snow. Get either wrong and you own a structure your building department will not permit, or one that is rated for less weather than your county gets.

This page covers what carports actually cost by size, what is in a kit and what putting one up involves, how to find the wind and snow numbers for your specific site, what “certified” buys you and when you need it, how these things are anchored, and — the part no dealer will tell you — the point at which a carport stops being the right answer and you should be pricing a building instead.

how much does a carport cost?

Carport pricing is unusually transparent compared with most of the building trade, because the dealers publish it. Here is what units actually list for, with the source named:

Size	Advertised price	Configuration
12×20	$1,295	Regular roof
12×21	$1,495	A-frame
18×20	$1,395	Regular style
18×21	$1,695	Regular style
20×20	$1,695	Regular roof
20×20	from $2,400	Installed
20×20	from $4,590	Vertical roof
24×26	$2,595	Regular roof
24×30	$8,159	Utility
30×36	$8,605	Steel
30×45	$18,735	—
30×55	$17,275 – $21,985	Varies by configuration

Broader industry figures put most carports between $3,000 and $10,000, with the full range across one-car to large RV covers running roughly $2,400 to $21,000.

What actually moves the price

Four things, in order of impact.

Roof style. This is the single biggest jump on the list above — a 20×20 goes from $1,695 in regular roof to $4,590 in vertical roof, roughly 2.7x for the same footprint. That is not a trim upgrade; it is a different roof system. Covered in detail below.

Certification. A certified unit carries additional bracing, sometimes heavier gauge steel, and engineered stamped drawings. It costs more and it is not optional if your jurisdiction requires a permit.

Gauge. The frame tubing is typically offered in 14-gauge or 12-gauge. Heavier gauge costs more and is often required for a certified unit at higher wind ratings. Note that gauge numbering runs backwards — 12-gauge is thicker than 14-gauge — which is a genuine source of confusion when comparing two quotes.

Enclosure. Every wall panel, gable end and door adds material. A fully enclosed unit is priced closer to a small building than to an open cover, which is the beginning of a larger question this page returns to at the end.

One car, two cars, three cars

The way most buyers actually think about it, and the sizes that go with it:

One car — 12×20 or 12×21 is the standard single. Adequate for a sedan or a small truck with room to open a door. Tight for a full-size pickup, and genuinely tight if you also want to walk around it.

Two cars — 18×20, 20×20 and 24×26 are the common doubles. 20×20 is the most-searched carport size in the country and it is a sensible default: two vehicles side by side with working room between them. 18×20 saves money and gets uncomfortable with two full-size vehicles.

Three cars — 30x wide and up. At this width you are into the sizes where prices climb steeply and where the comparison against an enclosed building starts to become real.

The honest advice on sizing is the same as for any building: the width you regret is always the one you cut. Adding four feet of width at order time is cheap. Adding it afterwards is a new unit.

Metal Carport Kits and DIY Installation

A large share of carport buyers are looking for a kit rather than an installed unit, and it is worth being clear about what that word covers, because it is used loosely.

What is actually in a kit

A carport kit is a bolt-together package: galvanized steel tube framing, roof panels, fasteners, bracing, anchors appropriate to your surface, and instructions. Most manufacturers use a slip-fit or bolt-together connection system specifically so the frame can go up without welding.

What is generally not included: the pad, any site preparation, the permit, and delivery beyond a stated radius. Those are real costs and they are where a “$1,695 carport” becomes a $2,400 one.

What erecting one actually involves

Two people, a day, and ordinary tools for a single or double. The frame goes up as a series of bows, gets braced, then panels go on. The genuinely difficult parts are two:

Getting the base square and level. Everything downstream depends on it, and a frame racked at the base will never sheet cleanly.

Anchoring it correctly for your surface. This is the step most likely to be done badly, and it is the step that decides whether the unit survives a windstorm. It gets its own section below.

Kit versus installed

Most dealers will install for a few hundred dollars over the kit price, and on a single or double that is frequently the better trade — they do it every day, they carry the liability, and the difference is often smaller than the value of your weekend.

The case for a kit is stronger when the site is difficult, when you are outside a dealer’s delivery radius, or when you want to modify the design. It is weaker than it looks if you have never squared a frame before.

Carport Sizes

The sizes people actually shop for, and what each one is genuinely good for:

Size	Sq ft	Typical use
10×20	200	Single compact car, motorcycle group, equipment
12×20 / 12×21	240–252	Standard single vehicle
16×20	320	Single vehicle with working room, or a small truck
18×20	360	Tight double
20×20	400	The standard double
20×30	600	Double with storage depth, or a boat
20×40	800	Two vehicles in tandem, RV, long boat
24×24 / 24×26	576–624	Comfortable double, small equipment
24×30 and up	720+	Three vehicles, tractors, commercial use

Length is cheaper than width. Frames are priced by the bay, and adding length adds bays; adding width means a longer span and a heavier frame. If you are choosing between 20×30 and 24×24 at similar money, think hard about which dimension you will actually miss.

Height is the dimension people forget. A standard leg height of 6 feet clears a car and nothing else. A pickup with a rack, a boat on a trailer, or anything you want to walk under with a load needs more, and leg height is much cheaper to specify than to change.

Roof Styles, and Why the Price Triples

Three styles, and the difference between them is not cosmetic.

Regular roof. Rounded corners, panels running horizontally along the length of the unit. The cheapest option and entirely adequate in mild climates. The weakness is that horizontal panels do not shed snow or debris well, because water and snow run across the ribs rather than along them.

A-frame / boxed eave. A peaked roof with boxed ends — it looks like a building rather than a shelter. Panels still run horizontally. Better appearance, better water shedding than regular, moderate price.

Vertical roof. A peaked roof with the panels running vertically from ridge to eave, with ridge caps and hat channel underneath. Water and snow run down the ribs and off. This is the only style that genuinely sheds snow, and it is the reason the price roughly triples on a 20×20.

Color is a longer decision than it looks

Panel color on a carport is chosen from a chart in about ninety seconds and then lived with for twenty-five years. Two things are worth knowing before that ninety seconds.

Dark colors run hot and fade harder. Under an open roof in full sun the difference is real, and reds and dark blues are the pigments that shift most over time. Light and mid-tone colors hold their appearance longest, which is why so much of the industry defaults to them.

Trim and roof are separate choices and most people treat them as one. A contrasting trim costs nothing extra on most order forms and does more for how the finished unit looks than the panel color itself.

If you are matching an existing building, or planning to add one later, choosing colors that hold up covers the finish systems and how they weather.

The rule: if you get meaningful snow, buy the vertical roof. Not as an upgrade — as the requirement. A regular-roof unit in a snow region accumulates load it was not designed to carry, and the failure mode is the roof, not the frame. In a mild climate, regular roof is a legitimate saving rather than a corner cut.

Certified vs Non-Certified: The Decision Nobody Explains

This is the most consequential thing on the page, and it is presented by the industry as an upsell rather than as what it is — a permitting decision you have to make before you order.

A certified unit is engineered to a specific wind and snow rating and comes with stamped drawings. In one dealer’s words: “Certified buildings include engineered stamped approval blueprints required to obtain a building permit.”

A non-certified unit is not. Another dealer puts it plainly: “Non-certified carports are simpler structures as they don’t need to be reinforced to survive severe weather. They are lighter and cheaper.”

The physical difference is real

It is not only paperwork. The bracing differs: a non-certified unit typically has “knee braces on four corners, and a channel peak brace,” while a certified unit has “a peak brace on every bow and knee braces on every leg.” Certified units also carry stated minimums — one dealer quotes “a minimum wind rating of 80mph, and is snow rated starting at 20lbs/sf” — where a non-certified unit may carry no rating at all, and in at least one case only a “10 day workmanship warranty.”

At the upper end, certification means something specific: one dealer’s “certified 26x21x6 vertical roof unit is able to endure 130 mph winds and 60 psf snow.”

When you need it

The industry’s own guidance is honest about this: “Local building authorities may require a permit, and if that’s the case, you will have to purchase a Certified building.” And conversely: “If your area doesn’t require a permit for carports – it’s probably OK if you decide to go with an uncertified unit.”

So the sequence is: call your building department first, order second. Ask two separate questions, because they have two separate answers:

1. Does a carport of this size require a permit here?
2. If so, do you require engineered stamped drawings?

Some jurisdictions exempt open structures under a square-footage threshold. Some exempt anything without walls or a permanent foundation. Some require a permit for anything anchored to the ground. There is no national answer, and a dealer three states away does not know yours.

If you are working out what your own state’s permitting looks like before you make that call, the state building code index covers permit authority, code adoption and design loads state by state.

Finding Your Own Wind and Snow Numbers

Here is the step almost nobody completes, and it takes about two minutes.

Design wind speed and ground snow load are properties of your address, not your state. They vary within a county. And when a dealer asks what rating you need, the correct answer is a number you looked up, not a guess.

Use the ASCE Hazard Tool (ascehazardtool.org). Enter your address, select Risk Category II, and it returns the design wind speed and ground snow load for that specific location. One of the better dealers in this market points buyers there directly, and adds the right framing: these “are specifications for your area, so you can always go more than, but never less than, shown.”

Two things to understand about the number that comes back:

Wind speed comes in two conventions and they differ by about 30%. Modern codes publish an ultimate design wind speed (Vult, a 3-second gust); older documents and some dealer literature quote a nominal or ASD speed. An ultimate 115 mph corresponds to a nominal 89 mph — the same building. Two quotes reading “115 mph” and “89 mph” may be describing identical structures. Always ask which convention a rating is in before concluding one supplier is under-building.

Exposure category moves frame weight more than a few mph does. Open terrain with scattered obstructions is Exposure C; suburban or wooded terrain is Exposure B. A unit quoted for B and installed on an open rural site is under-designed for where it actually stands.

Anchoring, and How It Connects to the Rating

Anchoring is treated as an accessory in most carport marketing. It is not — it is the load path. A certified 130 mph unit anchored as though it were a garden shed is not a 130 mph unit.

Three surfaces, three anchor types:

Concrete. Concrete expansion anchors, also called wedge anchors, drilled to minimum depths around 3.75 inches. This is the strongest and simplest attachment, and it is the reason a slab is worth pouring if you are near the decision.

Bare ground. Helical auger anchors, which screw into undisturbed soil and resist uplift by bearing against it. Effective when installed to depth in soil that will hold — much less so in loose sand or saturated clay.

Asphalt or rocky ground. Barbed drive anchors, driven rather than screwed.

The question to ask your dealer, in these words: “What anchor type and spacing does my certification require for my surface?” A certified unit’s rating is contingent on being anchored the way the engineer assumed. A dealer who cannot answer that has sold you a rating, not a structure.

If you are pouring a pad rather than anchoring to ground, pouring a pad for it covers thickness, edge detail and the anchor-bolt pattern.

Enclosed Carports, and Turning a Carport Into a Garage

A large number of people arrive at a carport and leave wanting something closer to a garage. It is worth understanding what happens as you add walls, because the economics change faster than most buyers expect.

Partial enclosure

One or two walls, or a back wall plus gable ends, is the sweet spot for a lot of buyers. It blocks the prevailing weather, adds real security against casual theft, and costs a fraction of full enclosure.

Full enclosure

At this point you have bought a small building with a carport’s structure. Add a roll-up door and you have a garage — and the price has moved into territory where a purpose-built garage building is a fair comparison rather than an aspirational one.

Two things change when you enclose:

The wind loading changes. An open carport lets wind pass through. An enclosed structure catches it, and the lateral load on the frame goes up substantially. This is why enclosing a non-certified carport after the fact is genuinely risky — the frame was engineered as an open structure, and you have changed its load case.

The permitting usually changes. Many jurisdictions that exempt open carports do not exempt enclosed structures. If you are planning to enclose later, ask about it now, not after the frame is up.

And once it is enclosed, it becomes a space with a climate. An uninsulated steel enclosure sweats in spring and roasts in summer, which matters the moment you store anything that minds — tools, a vehicle you care about, anything with electronics. How insulation gets installed covers the assemblies and where condensation actually comes from.

The honest comparison

An independent cost comparison puts a 20×20 carport at around $7,200 installed against a 20×20 garage at around $33,200. That is a real gap and it is the reason carports exist.

But that garage figure is for conventional stick-built construction. A steel building kit sits between the two, and it is the option most carport buyers never price. If you are considering full enclosure, browse the kit catalog before committing — the comparison is closer than the $7,200-versus-$33,200 framing suggests, and it comes with a genuine building rather than a converted cover.

For the version with a slab, doors and a proper wall system, what a metal garage kit includes covers the smallest size most people consider, and stepping up to a 40×60 is where most buyers who start at a carport eventually land.

RV, Boat and Equipment Covers

The single most common non-car use, and the one where sizing errors are most expensive.

RV covers are a height problem, not a floor-area problem. A Class A coach runs 12 to 13.5 feet tall; a fifth-wheel with air conditioners on top is similar. A standard 6-foot leg height is useless. Specify leg height from your actual vehicle’s height plus clearance, and measure it rather than trusting the brochure figure — roof-mounted equipment is frequently omitted from published heights.

Length matters more than people plan for too. A 40-foot coach in a 40-foot cover has no room for the door to swing or for you to walk around the back. Twelve feet of extra length is a couple of bays and is cheap by comparison.

For the fully covered version with walls and a door, an enclosed RV garage walks through the eave heights and door sizes the common coach classes actually need.

Boats are a width and height problem — trailer bunks make them taller than they look on the water, and a wake tower or a hardtop changes the answer entirely.

Tractors and equipment are usually a length-and-height problem, and are the one use where a regular-roof unit at a large size is often perfectly appropriate, because nothing about the use requires weather-tightness. If the equipment needs to be secured rather than merely covered, enclosed storage under one roof is the version with walls and a door.

When a Carport Is the Wrong Answer

This is the section a dealer will not write, and it is the most useful one here.

A carport is the right answer when you need cover rather than enclosure, the budget is genuinely constrained, the structure is temporary or may need to move, or the thing being covered does not need protection from anything except direct sun and rain.

A carport stops being the right answer at three specific points.

1. When you are fully enclosing it

Covered above. Once you are buying walls, gable ends and a door, you are buying a building with a carport’s bones — and the frame was engineered for a different load case.

2. When the size crosses roughly 30 feet wide

Look again at the price table at the top. A 30×45 lists at $18,735. A 30×55 runs $17,275 to $21,985. A larger commercial unit was quoted at $42,471.

A 30×40 engineered steel building kit runs $21,000 to $24,700 for the kit — clear-span, red-iron or heavy-gauge framing, engineered to your address, permit-ready by design.

In that overlap zone, a tube-frame “commercial carport” and a real engineered building cost approximately the same money, and almost no buyer realizes they are choosing between two very different products. This is the single most expensive mistake available in this market, and it is invisible unless someone puts the two prices side by side.

To model your own numbers against your dimensions rather than a published range, run the cost calculator, or see prices across every size for where each footprint lands.

3. When you need it to be permanent, permitted and financeable

An open, non-certified, ground-anchored carport is frequently not a permanent improvement in the eyes of a building department, an appraiser, or an insurer. If the structure needs to appear on a permit, add value at sale, or be covered on a policy as a building, that is a different product.

None of this means don’t buy a carport. It means know which of the three situations you are in before you order, because the answer changes what you should be shopping for.

Frequently Asked Questions About Carport Kits

Compare Carport and Building Prices Before You Order

Three things settle a carport purchase, and all three are free:

Call your building department. Permit required, and stamped drawings required — two questions, two answers, and they determine whether you are shopping certified or not.

Look up your address on the ASCE Hazard Tool. Two minutes, and it converts “what rating do I need” from a guess into a number.

Price the alternative if you are near the line. If you are fully enclosing, or shopping anything 30 feet wide or larger, get one steel building kit quote alongside your carport quotes. They frequently land closer than expected, and it is the only way to find out.

When you are ready, put it out to multiple suppliers on a specification you have actually pinned down — the certification, the loads and the anchor spec named — and the differences will show up in the numbers rather than in the fine print later.

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