Short answer. In a flat, the pipes usually decide: the toilet stays near the soil pipe, and the rest is arranged around it. A standard bath needs a wall about 1.7 m (5 ft 7 in) long; below that, a shower usually gives more. Leave about 60 to 75 cm (24 to 30 in) clear in front of the toilet and about 70 cm (28 in) in front of the basin, and make sure the door opens without hitting anything. The numbers here are common guidelines, not rules: local building rules and the makers' instructions come first.
Standard room sizesKitchen layout basicsHow to read a floor plan
Start with the pipes
The toilet's soil pipe, about 100 to 110 mm (4 in) across, needs a steady fall to the building's shared stack, so in a flat it often fixes where the toilet goes; moving it may mean a raised floor, boxing or a pump, and the building's permission. Basin, bath and shower wastes (32 to 40 mm) are easier to move but need a fall too. Many rules ask for an extractor fan with a way out, and electrics near water need a qualified electrician.
Shower or bath?
| Option | Space it usually needs | Watch |
|---|---|---|
| Standard bath | About 170 × 70 cm (5 ft 7 in × 2 ft 4 in) | It takes a whole wall |
| Short bath | About 150 to 160 cm (4 ft 11 in to 5 ft 3 in) long | Tall people lie bent |
| Shower bath | About 170 cm long, wider at the shower end | A fixed screen keeps water in better than a curtain |
| Square shower tray | Commonly 80 × 80 to 90 × 90 cm (32 to 36 in square) | Below about 80 cm it feels cramped |
| Wet room | A tiled floor that falls to a drain | The slope and the waterproofing must be right |
With young children a bath is often worth the squeeze; otherwise a generous shower usually beats a short bath with everything crowded round it.
The door
An inward door sweeps the floor of a small room. Swap the hinge side so it opens against a bare wall, open it outwards if the hall allows (it can then be opened if someone falls against it), or use a sliding or pocket door. Shower doors swing too: a sliding door or a fixed panel saves space.
Clearances: common guidelines
| What | Common guideline | Why |
|---|---|---|
| Toilet centre to the side wall or next fitting | About 40 to 45 cm (16 to 18 in); US codes set a minimum of 15 in (38 cm) | Elbows and shoulders |
| Clear space in front of the toilet | About 60 to 75 cm (24 to 30 in); US codes allow 21 in (53 cm) at least | Knees, and standing up |
| Clear space in front of the basin | About 70 cm (28 in); about 55 cm (22 in) feels tight | Bending over the basin |
| Space to step out of a shower or bath | About 70 cm (28 in) along the opening | Drying off |
A bathroom that must suit a wheelchair needs much more space.
Layouts, storage and light
- Everything on one wall keeps the plumbing simple and the floor clear; a bath across the end suits a long, narrow room; a corner shower leaves two walls free.
- Wall-hung toilet and basin show the floor underneath; the cistern frame needs a false wall about 15 to 20 cm (6 to 8 in) deep.
- Storage: a mirror cabinet, a vanity unit hiding the pipes, a niche in a thick shower wall, hooks near the shower.
- Light: more than one light, and light at the mirror from the sides, not only from above.
Try the layout in 3D
In Flatwalk the bathroom is built piece by piece along the walls of your own plan, with floors, tiles and paint. Choose the door type, walk in at eye level, measure the space in front of the toilet with the tape measure, and add lights to see a windowless bathroom lit. Flatwalk does not check these guidelines for you and does not know where your pipes run: measure the real room and ask a plumber first.
What Flatwalk does that older planners skip
Lights
Add ceiling lights and LED strips and see the mirror and the shower lit, not only drawn.
Your flat in its city
Give the address and the street and buildings around you appear in 3D where the map has them.
Sun for your address
If the bathroom has a window, see whether the morning sun reaches it, by date and hour.
One piece, in your own room
Through the live camera or in a photo of the room, stand a piece of furniture on your own floor at its true size before you buy.
Detail
Bathrooms, kitchens and wardrobes built piece by piece, with floors, tiles and paint, and dozens of door types.
Made for a thumb
Tap the start and end of a line to measure the space in front of the toilet.
Swipe for more. Every picture is the app itself.
One flat, free
Most people plan one home. For that, Flatwalk costs nothing: no trial clock and no card. Drawing the flat, building the bathroom, the tape measure, furniture, lights, sun and walking are all part of it, and each AI tool gives one free try. A membership is for people who want more flats or more AI.
Questions people ask
How small can a bathroom be? As a rough guide, a shower room with a toilet and basin can fit in about 2.5 to 3 m² (27 to 32 sq ft), and a bathroom with a full-size bath in about 3.5 m² (38 sq ft) or more. The shape and the pipes matter as much as the area.
Is a shower or a bath better in a small bathroom? If no wall is about 1.7 m (5 ft 7 in) long, a shower usually works better. A bath is often worth it with young children.
Can I move the toilet in a flat? Sometimes, but the soil pipe needs a fall to the shared stack, so it can mean raising the floor, boxing pipes or a pump. It is one of the costliest changes. Ask a plumber, and the building, first.
How much space do I need in front of a toilet? A common guideline is about 60 to 75 cm (24 to 30 in). Some codes allow less, but it feels tight.
Flatwalk lets you build your bathroom piece by piece in a 3D plan of your own flat, walk in at eye level and measure it, free for one flat. It is launching on Google Play; join the waiting list at flatwalk.app.
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