- Key Highlights
- What 900 Square Feet Actually Gives You
- Why a Square Footprint Is More Flexible Than a Rectangle
- When 30x30 Is the Wrong Size
- 30x30 as a Garage or Workshop
- 30x30 as a Metal Barn
- 30x30 as a Barndominium Shell
- 30x30 Garage vs Barn vs Barndominium Shell
- Site Prep, Delivery, and Install on a 30-Wide Building
- What Actually Moves the Price on a 30x30
- Picking Your 30x30
Thirty by thirty is the size buyers land on when they know they need real space but they are not ready to commit to a 40-foot-wide footprint. It shows up on our phones every week. Somebody has a truck, a tractor, a project car, or a plan to move onto their land, and a 30x30 metal building is sitting in their shopping cart while they try to figure out whether they are buying a garage, a barn, or the shell of a future home. The steel is close to identical in all three cases. What changes is where the doors go, how tall the legs are, and what your county wants to see before you pour concrete.
Key highlights
- A 30x30 gives you 900 square feet of covered footprint, square on all sides, with no interior posts eating into the floor.
- The square footprint is worth more than the number. You can change which wall you drive in through late in the design without redrawing the whole building.
- Door placement drives leg height. A roll-up on the sidewall needs roughly 2 feet of leg above the door opening. A roll-up on the gable end can use almost the full leg height.
- At 30 feet wide you are right at the edge of what can still go on a level ground pad instead of concrete. One more foot of width and the answer changes.
- Legs taller than 12 feet mean you provide a telescopic reach forklift on install day, which is why 12 feet and 14 feet are not the same conversation.
- We build and install the shell. Concrete, dirt work, electrical, plumbing, and interior framing are yours to hire out.
- Call (208) 572-1441 and we will price the exact configuration for your county's wind and snow load.
What 900 square feet actually gives you
A 30x30 offers 900 square feet of uninterrupted space thanks to its clear span design. Everything inside that box is usable, which is what often separates a steel building from a stick-built garage.
The 30-foot dimension is measured across the frame, so your interior will likely land a few inches under 30. Plan around 29 feet 6 inches when you are laying out equipment, and you will never be surprised on install day.
Why a square footprint is more flexible than a rectangle
A 30x30 is the same in both directions, so you can drive in through either wall. On a rectangular building, the long wall is a sidewall and the short wall is the gable end, and that is locked the moment the frame is engineered.
On a square building, either facade can carry your main opening. So if the driveway approach changes, or the county makes you shift the building 15 feet from where you planned, you are not starting the layout over.
When 30x30 is the wrong size
Parking two full-size trucks side by side in a 30x30 metal building and still walking around them works, until you add shelving and lose 2 feet of width. Storing a fifth wheel or a toy hauler is a length problem, so look at our RV carports and covers instead. And if the building has to hold a business or an ag operation that grows, a 30x40 footprint costs less per square foot, because you are adding length to a frame you already paid to engineer.
Not sure whether 900 square feet is enough for what you are hauling into it? Call us at (208) 572-1441 and describe what is going inside. We size buildings around equipment every day.
Need help sizing the building before you order? Get a free quote or call (208) 572-1441 and tell us what you need to fit inside.
30x30 as a garage or workshop
A 30x30 garage holds two vehicles side by side with a real work bay behind them, or three nose to tail if you set it up as a drive-through. This is the most common way our 30-wide buildings get used, and it is where door placement does the most work.
Roll-up door placement changes your leg height
A roll-up door on the sidewall needs about 2 feet of leg height above the top of the opening. The header bar has to sit somewhere, and the door has to have room to coil above the opening without fouling the eave. So a 12x12 roll-up on the sidewall of a building with 12-foot legs does not fit. You need 14-foot legs for that door on that wall.
Put the same door on the gable end and the math changes, because the roofline rises toward the peak and gives you clearance the sidewall does not have. That one decision moves the price more than most of the cosmetic options. Our metal building height guide breaks down sidewall, peak, and clear height.
Pick leg height for what you will do inside, not what fits today
Ten-foot legs handle daily parking and general storage. Twelve feet gets you room for a lifted truck, an RV bay door, or overhead racking above the bay. Fourteen feet is what you want if a two-post car lift is anywhere in your future, because a vehicle at working height plus the lift structure eats close to 12 feet of clear space before you count the roof.
You’ll want to make sure you plan ahead to frame out any doorway ahead of time. Because cutting a doorway into finished steel afterward is much more expensive than planning it ahead of time. You’ll also want to put the walk-in door on a different wall than your roll-ups, so you are not squeezing past a parked truck every time you go for a wrench. Configurations are on our metal garages and workshop buildings pages.
30x30 as a metal barn
As a barn, a 30x30 shelters hay, implements, livestock, or a mix of all three. It provides ample room for large pieces of equipment and is flexible enough to work in any agricultural project.
Roof style changes your usable overhead space
A vertical A-frame roof sheds snow and water down the panel ribs and off the eave, which is what you want in any region that gets real winter. A gambrel roof has the barn profile with the double-pitch break, and that break buys you meaningful headroom in the upper section at the same leg height. If a hay loft or overhead storage is part of the plan, the gambrel earns its cost. Our two stock 30x30 barns are gambrels for exactly that reason, alongside the 30x30x12 A-frame barn for buyers who want the simpler profile.
Horizontal panels are the budget option on the walls. Vertical panels cost more and are worth it, because water runs down a vertical rib and off the building instead of sitting in the seam of a horizontal lap. Over 20 years on a barn that regularly sees snow, that difference shows up in the steel. The full breakdown to roofing can be found in our guide to metal building roof styles.
Open ends and lean-tos stretch the footprint
Leaving one end open gives you drive-through access for a tractor with an implement still attached, and it keeps air moving in summer, which matters for stored hay and for animals.
A lean-to on the side is the cheapest square footage you will ever buy from us. It shares the main frame, so you are paying for legs, purlins, and roof panels rather than a whole new structure. A 12-foot lean-to running the 30-foot length adds 360 square feet of covered space for equipment or a boat. Just make sure your concrete or footings account for it before the pour, because crews show up with anchors matched to what the drawings say, and a lean-to planned as an afterthought is the single most common site mismatch we see. Configurations are on the metal barns page.
Compare 30x30 barn configurations: See the 30x30x10 Gambrel Barn or the 30x30x12 Gambrel Barn to compare roof profile, height, and storage options.
30x30 as a barndominium shell
Nine hundred square feet is small for a full-time family home and close to perfect for a shop with living quarters, a guest house, or a first structure on raw land. Plenty of buyers put a 20x30 shop on one side and a 10x30 living space on the other, then finish the interior over a couple of seasons.
Occupancy means Risk Category II and stamped drawings
Any building you plan to occupy has to be engineered to Risk Category II, and your building department will want stamped engineered drawings specific to your address before it issues a permit. This accounts for the wind and snow loads your county actually sees.
Order those drawings early. They take a few weeks to come back from the engineer, and your permit review runs after that, not alongside it. Our explainer on certified permits, wind loads, and snow loads covers what the stamp includes, and the snow and wind load page shows how those numbers change the frame.
We build the shell, you finish the inside
The shell is the exterior structure: frame, panels, roof, doors, windows, and openings, delivered and installed. Concrete, dirt work, plumbing, electrical, HVAC, and every interior wall get hired out to your local trades.
That split is why the steel goes up in days while the finish work takes months, and it means you control the interior budget instead of paying a general contractor's markup on drywall. Start with our steel frame barndominium breakdown, then look at layouts on the barndominium shells page.
30x30 garage vs barn vs barndominium shell
Same footprint, three different builds. Below, we’ve put together a table that shows what actually changes.
| What changes | Garage or workshop | Metal barn | Barndominium shell |
|---|---|---|---|
| Typical leg height | 10 to 14 ft | 10 to 12 ft | 12 to 14 ft |
| Walls | Fully enclosed, all four sides | Often one or both ends open | Fully enclosed, insulated |
| Main opening | Roll-up doors plus a walk-in | Wide open bay or sliding access | Framed openings for residential doors and windows |
| Roof style | Vertical A-frame | Vertical A-frame or gambrel | Vertical A-frame |
| Foundation | Concrete slab preferred | Ground, gravel, or concrete | Engineered concrete slab required |
| Engineering | Certified to local loads | Certified to local loads | Risk Category II, stamped drawings |
| Common add-ons | Insulation, extra frame-outs, windows | Lean-tos, wainscot, open gable | Full insulation, lean-to porch, upgraded panels |
Site prep, delivery, and install on a 30-wide building
At 30 feet, a level ground or gravel pad is still on the table for barns and open structures. Wider than that, the load on each leg concentrates enough that we require concrete. Your building department may require concrete regardless, and anything occupied always needs an engineered slab.
Level matters more than material. Crews have a couple of inches of play in each leg. Past that, the site has to be graded before the truck arrives, or the install gets rescheduled. Our site preparation guide covers grading tolerance, and the ground anchors versus concrete anchors comparison explains which anchor system goes with which surface.
What actually moves the price on a 30x30
Two 30x30 buildings can be thousands of dollars apart, and the square footage is almost never the reason. Price moves on leg height, on how many openings you cut into the walls, on panel and tubing gauge, on insulation, and hardest of all, on the wind and snow loads your county enforces. A 30x30 in west Texas and the same 30x30 in a Colorado mountain county are two different buildings structurally.
Standard is 14-gauge tubing and 29-gauge panels. Upgrades to 12-gauge tubing and 26-gauge panels are available, and in heavy snow country the upgrade often pays for itself. Our 12-gauge versus 14-gauge framing comparison covers when the heavier tubing is worth it.
Financing and rent-to-own are available. Details are on the financing page, and the ordering process page walks through what happens between your deposit and your install date.
"Design your 30x30 in 3D at EngineeredMetalBuildings.com, or call (208) 572-1441 and we will price it against your county's actual loads before you commit to anything."
Picking your 30x30
The footprint is the easy part. Choosing between garage, barn, or barndominium shell comes down to three decisions: which wall you drive in through, how tall the legs need to be for the tallest thing going inside, and whether anyone is going to sleep in it. Answer those and the rest of the spec sheet follows.
Design your building in 3D at EngineeredMetalBuildings.com, or call (208) 572-1441 and tell us what is going in it. We will work through the openings, the loads, and the site before you put money down.
- Key Highlights
- What 900 Square Feet Actually Gives You
- Why a Square Footprint Is More Flexible Than a Rectangle
- When 30x30 Is the Wrong Size
- 30x30 as a Garage or Workshop
- 30x30 as a Metal Barn
- 30x30 as a Barndominium Shell
- 30x30 Garage vs Barn vs Barndominium Shell
- Site Prep, Delivery, and Install on a 30-Wide Building
- What Actually Moves the Price on a 30x30
- Picking Your 30x30
Frequently Asked Questions
We manufacture, deliver, and install the shell. You are not assembling anything. Your responsibilities are the site work, the concrete if your build requires it, and permitting. Check coverage on our service area page.
A 30x40 usually costs less per square foot, because adding 10 feet of length to an existing frame is cheaper than the first 900 square feet.
Ten feet covers standard parking and storage. Twelve feet gives you clearance for a lifted truck, taller roll-up doors, or overhead racking. Fourteen feet is the right call if you plan to install a two-post car lift.
You can, provided the building is engineered to Risk Category II and your county issues a permit based on stamped engineered drawings for your address. Nine hundred square feet works well as a shop with living quarters, a guest house, or a compact primary residence. We supply the shell only, so interior framing, plumbing, and electrical are handled by your local trades.
Often yes, if the pad is level and the building is not going to be occupied. At 30 feet wide you are at the upper end of what installs cleanly on a compacted ground or gravel pad. Anything occupied, and anything wider than 30 feet, needs an engineered concrete slab.
Two full-size vehicles fit side by side with room to open both doors, plus a work bay behind them. Three fit nose to tail if you set the building up as a drive-through with openings on opposite walls.
A 30x30 metal building covers 900 square feet.
