The honest answer is: you do not, we do. Off-the-shelf shower kits ask you to measure because they have to make do with whatever comes back. A bespoke screen is templated by us at the survey stage to within a couple of millimetres. But if you want to ballpark the cost of your project before you call us, here is what to look at.

Step 1: Decide the layout

The four most common are:

Single walk-in panel (one fixed panel, open one end)
Walk-in with return (one main panel plus a small return at the open end)
Frameless hinged door (a single hinged door, no frame)
Three-sided enclosure (two side panels, a hinged or sliding door at the front)

Layout affects cost more than size does. A single fixed panel is the simplest thing we make. A three-sided enclosure with a hinged door has four times the hardware, four times the sealing detail and considerably more that has to line up.

Step 2: Take rough measurements

You only need ballpark figures at this stage. Pick a spot on the tiled wall and a spot on the floor, both clear of obstructions. Measure:

The full width of the shower opening
The full height from floor to ceiling (or to the top of the tiles)
The depth of any tray or wet room area

Round to the nearest 10mm. Take a couple of photos. That is enough for us to put a rough price together.

Why walls are never square

This is the part that catches almost everybody out, and it is the single reason DIY measuring goes wrong.

Take your width measurement three times: once near the floor, once at roughly waist height, once near the top. In a new-build you might get three identical numbers. In a Victorian terrace in Hove or a 1930s semi in Worthing, it is entirely normal to find 15mm or more of variation between top and bottom. Walls lean, plaster builds up in corners, and tiling can add its own bow.

Now do the same for plumb. Hold a spirit level vertically against the wall where the panel will sit. If the bubble is off, the wall leans, and a rectangular panel cut to your widest measurement will not sit against it.

A single measurement taken at one height, given to a manufacturer, produces a panel that fits at exactly that height and gaps at every other. That gap is where the water goes.

How a proper template deals with it

There are three ways to absorb an out-of-square opening, and the right one depends on how bad it is.

Wall profiles. A U-channel or wall profile with adjustment built in, typically giving 5mm to 10mm of movement. This is the standard approach and handles most ordinary variation invisibly.

Scribing. The glass edge itself is cut to follow the wall, rather than cut straight. This gives the cleanest frameless look with no profile at all, but it is only possible because the glass is cut to a physical template of your actual wall. It also means the panel fits your opening and no other.

Rebuilding the wall. Where the lean is severe, the honest answer is that no amount of glass trickery fixes it and the wall needs packing and re-tiling. We would rather tell you that at survey than fit something that looks wrong.

Step 3: Make sure the bathroom is finished

The most important thing on the day of the survey is that tiling and floor work is complete. We measure the actual wall, not the wall-as-it-should-be. If we template to half-tiled walls and you finish them differently, the panel will not fit.

The same applies to the tray. It must be installed, levelled and bedded before templating. A tray that shifts 3mm when it is finally bedded takes the panel out of alignment with it.

We know this is inconvenient when you are trying to compress a bathroom refit into two weeks. But toughened glass cannot be trimmed after it is made. Every edge and every hole is finished before the panel goes through the toughening furnace, and once it has been through, a panel that is 4mm too wide is scrap rather than a five-minute adjustment.

What to think about before the survey

Glass thickness. 8mm is standard. 10mm for big panels and frameless doors.
Easy-clean coating. Worth it on the Sussex coast, the water is hard.
Fittings finish. Chrome (cheap, classic), brushed nickel (good in modern bathrooms), brushed brass (warm, on-trend), matt black (industrial).
Glass type. Clear is standard. Tinted (smoke, bronze, grey), frosted, fluted and patterned are all options.

On the easy-clean coating: most of Sussex sits on chalk, and the water here is genuinely hard. Untreated glass will show limescale spotting within weeks and it etches into the surface over time. A factory-applied hydrophobic coating is baked on rather than wiped on, and it makes the difference between a wipe-down and a scrubbing job. It is one of the few upgrades we recommend more or less universally in this area.

Where the door should hinge

Worth thinking about before we arrive. A hinged shower door should open outwards into the room, and it needs clear space to do so. Check what is in that arc: a basin pedestal, a radiator, a towel rail or a door swinging the other way will all conflict.

In a small bathroom this frequently decides the layout, and it is why walk-in panels have become so popular in Victorian and Edwardian bathrooms where there simply is not room for a door to swing.

Lead times

Allow around two to three weeks from template to fit for bespoke toughened work, and longer if you have chosen a special glass or a non-stock hardware finish. If you have a plumber booked, give us that date at survey and we will tell you honestly whether we can hit it.

Want a quote? Visit our shower screen service page or request a free quote.

How to measure for a shower enclosure