Start with the shower size
Square shower enclosures are widely sold at 760mm, 800mm, 900mm and 1000mm. Rectangular trays commonly run from 1000mm up to 1700mm long, which lets a shower take the place of a bath in the same footprint.
Anything under about 800mm feels tight for most adults, especially when washing hair. If the room allows it, 900mm is a comfortable minimum for a square shower, and a rectangular tray gives the most usable space for its width.
| Shape | Typical sizes | Suits |
|---|---|---|
| Square | 760, 800, 900, 1000mm | Compact en suites and corners |
| Rectangular | 1000 to 1700mm long, 700 to 900mm wide | Long narrow rooms, bath replacements |
| Quadrant | 800, 900, 1000mm | Corners where a door needs to swing past |
Space around the toilet and basin
A toilet needs clear space in front of it to sit and stand comfortably, and room either side so it does not feel boxed in. Wall-hung toilets and short-projection pans help in shallow rooms because they sit closer to the wall.
Basins come in slim cloakroom sizes as well as full widths. A small basin on a vanity unit gives storage without taking more floor, and a corner basin can rescue an awkward layout.
Leave enough space in front of the basin to bend over it without hitting the shower screen or the door. That clearance is what makes a small en suite feel usable rather than cramped.
Layouts that work in small rooms
In a long, narrow room, the usual answer is shower at the far end, toilet and basin along one wall, and the door at the opposite end. A rectangular tray across the full width uses the end wall completely.
In a square room, putting the shower in a corner with a quadrant or pivot door keeps the centre of the room clear.
A sliding or pocket door into the en suite, or an outward-opening door, frees the floor space an inward door would sweep. It is one of the simplest ways to gain usable room.
Plumbing and extraction to plan for
The toilet needs a route to the soil pipe, which is the least flexible connection in any bathroom. Where the toilet can go is often decided by where the soil stack runs, so it is worth checking before settling on a layout.
An en suite built off a bedroom needs good extraction to stop steam reaching the bedroom. A correctly sized extractor fan, run on after the light goes off, is essential rather than optional.
If the en suite is going into a loft or a converted room, check the ceiling height over the shower and the fall available for the waste before choosing the tray position.
Making a small en suite feel bigger
Clear glass, wall-hung units that show more floor, large-format tiles with fewer grout lines and a mirror cabinet instead of a separate mirror and shelf all make a small room feel more open.
Recessed niches in the shower wall give storage without anything sticking out. They need planning before the walls are boarded and tiled, so decide on them early.
Where to read next
Questions we get asked most
What is the smallest size for an en suite?
A shower, toilet and basin can fit into a very compact room if the layout is planned carefully, but the exact minimum depends on the room shape, door position and shower size. Measuring on a survey is the reliable way to know.
What size shower is best for an en suite?
900mm square is a comfortable minimum for most adults. In a narrow room a rectangular tray often gives more showering space for the same width.
Can I put an en suite anywhere in a bedroom?
The toilet position is the main limit, because it must connect to the soil pipe. Showers and basins are more flexible, but the waste still needs a workable fall.
Does an en suite need an extractor fan?
Yes. An en suite opens into a bedroom, so a properly sized extractor fan is needed to clear steam and stop condensation and mould.
Is a sliding door better for a small en suite?
Often, yes. A sliding or pocket door does not sweep across the floor, so it frees space for the basin and toilet.