Shower doors are sold by a nominal size — 700mm, 1200mm, 1700mm. That number tells you roughly what opening it fits. It does not tell you how wide the gap is when you step through, and it doesn't tell you whether the door will actually fit your wall.
Both of those catch people out regularly. Here's how to get it right.
1. Measure the adjustment range, not the size
Every shower door has an adjustment range — a span of a few centimetres it can be set to, because bathroom walls are almost never plumb. A 700mm door doesn't fit a 700mm gap; it fits an opening of 650–690mm.
So: measure your recess at floor level, at handle height, and near the top, then work to the narrowest of the three. If that figure sits inside the range, the door fits.
How much adjustment you get varies by product type:
- Shower doors — around 40mm
- Side panels — around 20mm, because they only adjust at the wall profile
- Quadrant enclosures — around 20mm on each wall
- Wetroom screens — only about 15mm, so measure carefully
If you fall between two sizes on a KV6 door, take the smaller one and make up the difference with the extension profile kit, which adds up to 20mm each side. Note this is a KV6 part only — there's no equivalent for the 8mm KV8 system, so on KV8 you must take the smaller door.
2. Entry width is the number that matters
This is the one nobody tells you. The gap you actually step through is often far narrower than the door size, and how much narrower depends entirely on the door type.
| Door | Nominal size | Actual entry |
|---|---|---|
| KV6 bi-fold | 700mm | 430mm |
| KV6 pivot | 700mm | 430mm |
| KV6 pivot | 900mm | 630mm |
| KV6 sliding | 1000mm | 400mm |
| KV8 hinged | 900mm | 760mm |
| KV8 sliding | 1700mm | 750mm |
Two things fall out of that table.
A 1000mm sliding door gives a narrower entry than a 900mm pivot door — 400mm against 630mm — despite being wider overall. On a slider, roughly half the opening is fixed glass. If you have the floor space to swing a door, a hinged or pivot door gives far better access per millimetre of wall.
Bi-fold and pivot give the same entry at every size. You aren't trading access for the swing. You're trading floor clearance for glass thickness.
If anyone using the shower is elderly, unsteady, or larger-built, buy on the entry figure.
3. Which door type?
Bi-fold
Folds inwards on itself, so it needs no clearance in front. The door for a tight bathroom where a swinging door would hit the basin, the loo or the doorway. Note the KV6 bi-fold uses 4mm glass rather than the 6mm used elsewhere in the range.
Pivot
Swings outward on a hinge. Simplest mechanism, fewest parts to fail, 6mm glass. Needs clear floor space for the arc — check nothing sits in it.
Sliding
Runs on its own track and takes up no floor space at all. The choice for a wider recess, especially where a bath has come out. Sizes to 1700mm.
Hinged
Like a pivot but hung from the edge, giving the best access for its width — 760mm entry on a 900mm door. Needs swing clearance.
Quadrant and offset quadrant
A complete corner enclosure with a curved front, so no sharp corners project into the room. Quadrant for equal walls, offset where one run is longer.
Useful to know: the enclosures are reversible but the trays are handed. You don't need to specify a hand for an offset quadrant enclosure, but you absolutely do for the tray underneath it.
Wetroom screens
A single fixed pane with no door — the most open option and the easiest to clean, with no track or rollers.
But your floor has to be right. A wetroom screen has no tray and no upstand. Water hits the floor and has to run away on its own, which means a fully tanked floor with a fall to a drain, or a wetroom former set into the joists. Fitted over a level, untanked floor it will flood the room. This is the single most expensive mistake in this category.
4. KV6 or KV8?
| KV6 | KV8 | |
|---|---|---|
| Glass | 6mm (4mm on bi-fold) | 8mm |
| Height | 1850mm | 1950mm |
| Easy-clean coating | No | Yes |
| Extension kit available | Yes | No |
The easy-clean coating is the practical difference, more than the glass thickness. Water beads and runs off rather than drying into limescale spots, so the glass needs wiping far less often.
Don't mix the two ranges. KV8 is 100mm taller, so a KV8 side panel next to a KV6 door will stand proud.
5. Recess or corner?
A door on its own suits a recess with walls both sides. For a corner, you add a side panel — and on our door pages you can select one from the dropdown rather than buying it separately.
The side panel is the depth of your shower and is chosen independently of the door width. A 900mm door with a 760mm panel is perfectly normal if that's the shape of your corner.
Before you order
- Measure the recess at three heights, work to the narrowest
- Check that figure against the door's adjustment range
- Check the entry width if access matters to anyone
- Check what's in the swing arc for hinged and pivot doors
- Decide recess or corner, and pick a panel depth if needed
- For wetrooms, confirm the floor is tanked and falls to the drain
Browse the full showering range, or read our guide to choosing a shower tray for what goes underneath.