Is a 6x4 shed actually 6ft by 4ft?

Usually not quite — and it's not a trick. "6x4" is a nominal size, a trade shorthand used across the whole industry. It tells you roughly what you're getting. It is not a measurement.

Three different numbers

Nominal size — the name. "6x4", "12x8". Approximate.

External size — the actual outside dimensions of the building, usually including the roof overhang.

Base size — the footprint the walls sit on, which is what your base needs to match.

These are all different, and the gap between external and base size can be several inches once you account for roof overhang, eaves and fascia boards.

What to do about it

Build your base to the base dimensions, not the external ones and definitely not the nominal name. We list the measurements separately on every product page.

Measure the space properly, including anything overhead — gutters, branches, washing lines cause more installation-day problems than fences do.

Check the route in. Panels for a large cabin will not go through a standard side gate. Measure the narrowest point between the road and where the building is going, and remember the panels are rigid.

Allow clearance. At least 300mm all round for maintenance; some installers require 600mm before they'll take the job.

Why the industry does this

Nominal sizes let you compare buildings quickly across makers. The trouble is each manufacturer measures from a slightly different point, so two "8x6" sheds from two brands can differ by a few inches in both directions.

If a few inches matters in your garden, work from the stated dimensions and nothing else. And if it's genuinely tight, ring us before you order — we'll check the exact figures with the manufacturer.