Five things to measure before you visit any kitchen showroom

Most first appointments at a kitchen showroom achieve very little. You describe your room, the designer draws something approximate, and everyone agrees to meet again once there are proper measurements. That second appointment is where the actual conversation happens.

You can skip straight to it. Fifteen minutes with a tape measure, a pencil and the back of an envelope is enough. Here is what to write down.

1. Wall to wall, at three heights

Measure the length of each wall three times: at floor level, at worktop height, and near the ceiling.

They will not match. In a house built before about 1950 they can differ by 30mm or more across a four-metre run, and in a stone cottage considerably more than that. This is not a fault. Walls bow, plaster builds up in corners, and floors settle.

It matters because cabinets are square and rooms are not. The difference between your smallest and largest measurement tells a designer how much scribing will be needed, whether a run will fit at all, and where the filler pieces have to go. A designer working from one measurement is guessing at the other two.

2. Ceiling height, in each corner

Measure floor to ceiling in all four corners of the room, not once in the middle.

Old floors slope. Ceilings sag. A 40mm difference corner to corner is ordinary, and it decides whether a tall larder will stand upright, whether cornice can run level, and whether the top of a run will need packing.

If there is a beam, measure to the underside of it as well as to the ceiling.

3. Every opening, and how far it sits from the corner

For each window and door: the width and height of the opening, and — this is the one people forget — the distance from the edge of the opening to the nearest corner of the room.

That last number decides whether a run of cabinets can reach the wall, or whether it has to stop short. It is the single most common reason a design changes between the first drawing and the second.

While you are there, measure the depth of the window reveal and the height of the sill from the floor. A deep reveal on a thick wall can swallow a worktop return. A low sill can stop a cabinet dead.

4. Where the water goes out

Find the waste pipe. It is usually a white or grey plastic pipe leaving the wall below the sink, and outside it will run to a gully or a soil stack. Measure how far it sits from the corner of the room, and how high it is off the floor.

Then note where the stopcock is, where the boiler is, where the gas meter is if there is one in the room, and where the consumer unit sits.

Moving a sink two metres is a morning's work for a plumber if the waste can run with a fall, and a much bigger job if it cannot. Nobody can tell you which until they know where the pipe is now. Everything else in a kitchen can be moved more easily than water.

5. The things you cannot move, and the ones you only think you cannot

Write down what is genuinely fixed: a chimney breast, a structural wall, a window, a soil stack.

Then write down what you have assumed is fixed but is not. Radiators move. Sockets move. Internal doors can be rehung to open the other way, which often gains a metre of usable wall. A boiler can usually be relocated for a few hundred pounds. Even a low window sometimes turns out to be cheaper to alter than to design around.

Most kitchens are laid out by accident rather than intention — they are where the previous owner put them, or where the pipes happened to be in 1974. It is worth knowing which constraints are real before you start arranging cabinets around them.

What else helps

Photographs of every wall, taken from the opposite corner. Include the ceiling and the floor in the shot.

A note of anything you have already bought — a range cooker, a sink, a particular tap. Appliance dimensions change a design more than most people expect, and a 900mm range is a different room from a 600mm one.

And roughly where you want to stand when you cook, and who else is usually in the room