The most common metal garage sizing mistake in the UK isn’t buying too small a garage — it’s buying one that technically fits the car and practically fits nothing else. A garage door closes on the car; it doesn’t open the car’s doors, walk past it with a bin, or leave room for a workbench. Below: the real size bands, what genuinely fits in each, and how to pick a size you won’t regret.
Standard metal garage sizes in the UK
- The market-standard single — around 3m wide × 6m deep. This is what most of the UK market sells as a “single garage”: it fits one car with modest clearance, and if the car and storage both need to fit, it’s the compromise you feel every week. It’s a size we deliberately don’t sell.
- The 4m single — where our range starts (4m × 6m, from £9,995 installed). That extra metre over the market standard is the difference between a garage and a tight box: one car plus real side storage — bikes, tools, garden kit — and doors you can actually open.
- Doubles — around 6m wide × 6m deep. Two cars, or — how many are really used — one car plus a workshop, gym corner or serious storage. The most flexible all-round size.
- Large/triple — up to around 9m wide. Multi-vehicle households, workshop businesses, or car storage plus a genuine working bay. Our steel range spans 4m to 9m widths.
We’ve compared the two most common bands head-to-head — costs, footprints, what fits — in single vs double garage.
Size the use, not the car
Measure your actual car, add what really needs to happen around it, and be honest about the second job the space will do:
- Car access: you want comfortable margin on width beyond the mirrors to use the doors like an adult — a modern SUV is over 2m wide with mirrors, and family-car door swing is what makes narrow singles miserable.
- The walk-past test: can you get from the door to the far end with the car inside? If not, everything stored at the back is effectively in long-term archive.
- The second use: workbench (600mm+ of depth against a wall), bikes (surprisingly greedy), gym kit, garden machinery. If any of these are real, a wide single is the minimum and a double is the comfortable answer.
- Height: roof racks, vans and storage lofts need eaves height checked, not assumed — it varies with roof style (apex, pent, lean-to).
Does a bigger metal garage need planning permission?
Often not — most garages sit within permitted development if they respect the height and coverage rules, but position (near boundaries, forward of the house, listed settings) changes the answer. Size itself also interacts with the 30m² building-regs threshold. Both are covered in our planning permission guide and building regulations guide — read those before fixing on a footprint, not after.
How size changes the price
Size is the biggest single price factor — more than finish, more than most extras. The simplest way to see it: price two or three sizes side by side in the configurator. It shows the live installed price as you change the size, so you can see exactly what the step from single to wide single to double costs — all-in, including the automated insulated door, delivery, installation and VAT. Full market context is in the metal garage price guide.
Metal garage size FAQs
What size is a standard single metal garage in the UK?
The market standard is around 3m × 6m externally. It fits one car — but see the honest caveats above about what “fits” means once you own it. It’s why our singles start at 4m × 6m instead: we don’t sell the 3m single.
What size metal garage do I need for two cars?
Around 6m wide × 6m deep as a working minimum. Two larger cars, or two cars plus storage, want more width or depth.
Can I get a metal garage in a custom size?
Ranges are typically built on standard widths and depths — ours spans 4m to 9m wide across the steel range — which covers the overwhelming majority of drives and uses. Configure the size options online to see what fits your plot.
Is it worth going bigger than I currently need?
Within your plot and planning limits — usually yes. The extra square metres are the cheapest they will ever be at build time, and nobody has ever complained that the workshop end of their garage is too roomy.
The bottom line
Size a metal garage for what happens around and beyond the car, not the car alone: a wide single if the garage has one job and a bit of storage, a double if it has two jobs. Check planning and building-regs thresholds before you settle on a footprint, and compare real all-in prices between sizes rather than guessing.
See the size options on the Steel & Metal Garages page — 4m to 9m wide, from £9,995 fully installed — or price your size online in a few minutes. Your deposit is fully refundable until you pay your balance.
Every VeltHaven building is delivered and installed by a UK-registered company (Companies House 17261887), with the VeltHaven 10-Year Structural Warranty (2 years full warranty + structural cover to year 10). Does not affect your statutory rights.