Bathroom Layout: How to Plan a Bathroom That Works for the Room

A good bathroom layout starts from the fixed points: where the soil pipe leaves the room, where the window is, and where the door opens. The toilet goes nearest the soil stack, the bath or shower takes the longest clear wall, and the basin sits where you have room to stand in front of it. Most bathroom layouts that feel wrong are fighting one of those three things.

Start with the soil pipe

The toilet connects to a 100mm soil pipe, and that pipe needs a steady fall to the stack. In most UK houses the stack runs down an external wall, so the toilet usually sits on or near that wall. Moving it further away is possible, but every metre adds work under the floor, and in older houses joist direction often limits where a pipe can run.

Basins and showers use smaller waste pipes and are much easier to move. That's why the cheapest layout change is usually swapping the positions of the bath and basin, and the most expensive is relocating the toilet. Our bathroom fitting in Kettering team maps the pipe routes on the first visit, before any layout is drawn.

Leave enough space around each fitting

A layout that fits on paper can still be awkward to use. As a working guide, allow:

• Clear standing space in front of the toilet and the basin (around 600mm is a common rule of thumb)

• Enough width either side of the toilet that you're not pressed against a wall or the bath

• Room to step out of the bath or shower without meeting the door or the toilet

• A door swing that doesn't hit a fitting (or a sliding or outward-opening door where it would)

Layouts for common bathroom shapes

Small square bathroom

Put the bath or shower along the back wall, with the toilet and basin side by side on the wall with the soil stack. A shower bath with a screen gives the choice of both in a small footprint. Wall-hung toilet and basin keep the floor clear.

Narrow bathroom

Run everything along one long wall: basin nearest the door, toilet in the middle, bath or shower at the far end. A walk-in shower at the end of a narrow room can replace the bath and make the room feel longer. Slim-depth basins and short-projection toilets give back walking space.

L-shaped or awkward rooms

Use the odd corner for the shower, where a quadrant or offset tray fills space nothing else would. Put the bath on the longest wall and keep the toilet close to the stack.

Larger family bathroom

Separate the zones: bath and shower apart rather than a shower over the bath, a double basin if the space allows, and the toilet out of the direct line of the door. A freestanding bath needs space around it for cleaning and to look right, usually more than people expect.

Showers, baths and wet areas

If the bathroom is used mostly for quick showers, a large walk-in shower may be a better use of space than a bath. Most buyers still like at least one bath in a family home, though, so if this is the only bathroom, a shower over the bath or a shower bath keeps both options, while a shower-only layout suits a second bathroom or an en suite. For level-access showers, the floor build-up and drainage decide what's possible, which we cover in our guide to wet rooms.

Ventilation and bathroom mould

Mould in a bathroom is almost always a ventilation problem, and the layout decides how well ventilation works. The extractor fan should sit high and near the shower or bath, where the steam is, and ideally opposite the door so fresh air is drawn across the room. A fan on the wrong side of the room barely touches the moisture.

Building regulations (Approved Document F) require extract ventilation in a new or newly created bathroom, and a fan with an overrun timer keeps running after the light goes off. Pair that with a window you can open and walls finished in moisture-resistant materials, and mould has little to grow on. Where an old bathroom already has mould, it usually needs treating and the fan replacing, not just repainting.

Getting the finishes to support the layout

Tile choice can make a layout feel better or worse. Large, light tiles and consistent flooring make a small room feel bigger, and a feature wall behind the bath or basin draws the eye to the best part of the room. Our post on what colour goes with beige bathroom tiles covers colour pairings.

How the layout affects cost

Keeping fittings in their existing positions is the cheapest route. Moving the basin or bath adds modest pipework, while moving the toilet or creating a wet room adds the most. We break down those differences in our guide to bathroom renovation cost.

Bathroom layout questions, answered

Should the toilet face the door?

Where you can avoid it, yes. Most people prefer the basin to be the first thing seen from the doorway, with the toilet to one side.

Can a bathroom have no window?

Yes, as long as it has mechanical extraction ducted to the outside. Internal bathrooms often need a fan that runs on for longer after use.

What's the minimum size for a bathroom?

A shower room with a toilet and basin can fit into roughly 2.5 square metres with careful planning. A full bathroom with a bath typically needs more like 4 square metres or above.

We design and fit bathrooms across Kettering and Northamptonshire with our own team, including bathroom fitting in Wellingborough, and we'll show you which layout changes are simple and which add cost before anything is agreed. You can see a finished room in our bathroom fitting project in Corby, or get in touch to book a visit.