The short answer
A small wet room of around 3m² typically costs in the £3,000–£5,000 range, covering the waterproofing membrane, drainage falls, tiling and standard fittings. A level, open floor can make a compact room feel larger, which is one reason wet rooms suit small bathrooms — but a tight space makes ventilation and a glass screen more important, not less, because spray and damp have less room to disperse. UK guidance puts bathroom extract ventilation at around 15 litres per second, and adding underfloor heating (often £300–£400 for a small room) helps the tiled floor dry and stay warm. The cost still depends on the subfloor and drainage route, so treat the range as a guide.
A small wet room can be a smart use of a tight space, but the details that keep it dry and comfortable matter more when the room is compact. Here is what one typically costs and what to plan for.
Small wet room basics
- Small wet room (~3m²)£3,000–£5,000
- Underfloor heating~£300–£400 per room
- Ventilation target~15 litres / second extract
- Glass screenrecommended in tight rooms
- Per square metre£1,500–£3,500
What a small wet room costs and needs
- Cost: around £3,000–£5,000 for a ~3m² room, covering tanking, drainage, tiling and standard fittings; still roughly £1,500–£3,500 per square metre.
- Ventilation: a compact room holds damp, so good extract — UK guidance is around 15 litres per second — is essential to keep mould down.
- Glass screen: a fixed or partial screen keeps spray off the far side of a small room and the toilet roll within it dry.
- Underfloor heating: often £300–£400 for a small room, it helps the tiled floor dry and takes the chill off.
| Item | Typical figure | Notes |
|---|---|---|
| Small wet room (~3m²) | £3,000–£5,000 | tanking, drainage, tiling, fittings |
| Per square metre | £1,500–£3,500 | as for any wet room |
| Underfloor heating | ~£300–£400 | small-room electric mat |
| Ventilation | ~£150–£500 | extract fan / system |
Indicative UK ranges for guidance. Sourced UK guidance from MyJobQuote and Bathroom Mountain cost guides.
Where a small floor plan helps or hurts
A level, open wet room floor removes the visual clutter of a tray and enclosure, which is why it can make a small bathroom read as larger. The flip side is that water and steam spread across the whole floor, so in a tight room a screen and proper ventilation do more work than in a big one. Plan the drain position so the falls are short and even, keep the toilet and any storage out of the direct spray zone, and budget for non-slip tiles. Get these right and a small wet room is one of the better uses of a compact space.
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Frequently asked questions
How much does a small wet room cost?
A small wet room of around 3m² typically costs £3,000–£5,000, covering the waterproofing membrane, drainage falls, tiling and standard fittings — still roughly £1,500–£3,500 per square metre.
Do small wet rooms need extra ventilation?
Yes. A compact room holds damp, so good extract ventilation — UK guidance is around 15 litres per second — matters more, not less, to keep mould and condensation down.
Is a glass screen needed in a small wet room?
It is strongly recommended. In a tight space a fixed or partial screen keeps spray off the far side of the room and helps the rest of the floor stay dry between showers.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific room. They are guidance, not a quotation.