Wet vs Electric Underfloor Heating: Which Is Best for Your Home?
Electric underfloor heating is cheaper and quicker to install, and wet (water-based) underfloor heating is cheaper to run. As a rule of thumb, electric suits single small rooms such as bathrooms, en suites and small kitchens. Wet suits larger areas, whole floors, extensions and new builds, where the lower running costs build up over time.
Wet systems also work well with heat pumps, because both run at low water temperatures.
Wet vs electric at a glance
| Electric underfloor heating | Wet underfloor heating | |
|---|---|---|
| How it works | Heating mats or cables under the floor | Pipes carrying warm water from your boiler or heat pump |
| Installation cost per m² (Checkatrade) | £50–£75 new build, £60–£85 retrofit | £85–£100 new build, £95–£110 retrofit |
| Running cost | Higher | Lower |
| Installation time (Checkatrade) | Single room usually 1–2 days | Single floor often 2–5 days |
| Floor height added | Very little | More, depending on the system |
| Best for | Bathrooms, en suites, small rooms, renovations | Whole floors, extensions, new builds, heat pump homes |
| Needs a heat source | No. Runs on electricity | Yes. A boiler or heat pump, plus a manifold and controls |
Installation costs
Checkatrade’s June 2026 guide gives these whole-house examples:
| Property | Electric | Wet |
|---|---|---|
| Terraced house (75m²), new build | £3,750 | £6,375 |
| Semi-detached (90m²), new build | £4,500 | £7,650 |
| Detached (140m²), retrofit | £8,400 | £13,300 |
Retrofitting costs more than fitting underfloor heating in a new build, because existing floors have to be lifted or built up.
Running costs
Checkatrade’s running cost examples (4 hours’ use a day) show wet systems costing roughly half as much as electric:
| Room | Electric (per day) | Wet (per day) |
|---|---|---|
| Lounge, 20m² | £1.96 | £1.05 |
| Kitchen, 14m² | £1.37 | £0.73 |
| Bathroom, 5m² | £0.49 | £0.26 |
These are only examples. Your real costs depend on your energy tariff, insulation, floor finish and how you use the heating. In a small bathroom the difference is small, so electric is often the practical choice there. Over a whole ground floor, it adds up.
Floor height and floor finishes
Electric mats are very thin and usually go straight under tiles or other finishes, so they add very little height. That makes them popular in bathroom refits.
Wet systems come in different types:
- Screed systems: the pipes are set into a screed layer. They’re common in new builds and extensions, and add the most height.
- Low-profile overlay boards: these sit on top of the existing floor and are designed for retrofits where height is limited.
- Joisted systems: these fit between floor joists, often with spreader plates.
Most floor finishes work, including tiles, stone, engineered wood, vinyl and many carpets. Thick carpet and underlay reduce heat output. Check that your chosen finish is suitable for underfloor heating before you buy it.
Can wet underfloor heating run off my boiler or heat pump?
Yes, both:
- Boiler: a mixing valve or blending unit brings the water temperature down to suit underfloor heating. Radiators elsewhere in the house keep running as normal.
- Heat pump: underfloor heating is a good match, because heat pumps work most efficiently at low flow temperatures.
How quickly does it warm up?
Underfloor heating warms up more slowly than radiators, especially screed systems, which hold a lot of heat. It works best on a steady timer or thermostat schedule, not switched on and off. Electric mats under tiles respond faster.
Which should you choose?
Electric makes sense if:
- it’s one small room, such as a bathroom, en suite or cloakroom
- you’re renovating and can’t raise the floor much
- you want the lowest installation cost and quickest fit
Wet makes sense if:
- you’re heating a whole floor, a large open-plan area or an extension
- it’s a new build, or the floor is being dug up anyway
- you have, or are planning, a heat pump
- you care most about long-term running costs
FAQs
Can I have underfloor heating in one room and radiators in the others?
Yes. This is very common. Wet underfloor heating in an extension or kitchen, with radiators elsewhere, works well with the right controls.
Does underfloor heating need servicing?
Electric systems need very little maintenance. Wet systems should have the manifold, pump and controls checked, and water quality should be looked after with inhibitor, as with any wet heating system.
Is underfloor heating worth it in an older home?
Often it is, especially in extensions or when floors are being replaced. Good floor insulation underneath matters a lot, or heat will escape downwards.