Underfloor heating (UFH) comes in two basic forms — electric mats that heat a floor directly, and wet systems that circulate warm water through pipe loops beneath it — and the underfloor heating cost for each is genuinely different, not just a matter of degree. In 2026, electric systems typically cost £40–£90 per square metre supplied and installed, which is why they're the usual choice for a single room. Wet systems cost £70–£100 per square metre when laid as part of a new floor or extension, but £120–£190 per square metre when retrofitted into an existing solid floor, and a full whole-house retrofit typically lands somewhere between £8,000 and £20,000 or more once manifolds, multiple loops, controls and floor preparation are all counted.
But the number that matters for your job isn't really "underfloor heating costs X" — it's which of those four scenarios you're actually in, because the gap between them is bigger than the gap between any one supplier's quotes. A bathroom retrofit and a whole-house new-build install are barely the same product.
I survey buildings and assess retrofit specs for a living; I don't install heating systems, so I've no reason to steer you toward the pricier option. What follows is 2026 pricing cross-checked against current UK trade cost guides, what actually moves the number, an honest read on wet versus electric and retrofit versus new build, and why underfloor heating has become the natural partner for a heat pump.
The short answer
Figures below were checked on 6 August 2026 against current 2026 cost guides from Checkatrade, MyBuilder and specialist UFH suppliers, cross-referenced against each other rather than taken from a single source. As with most trades in this series, installers in the South East — Dom’s patch included — trend above the national figures quoted here.
| Scenario | Typical cost (2026) | What's included |
|---|---|---|
| Electric, single room retrofit | £40–£90/m² | Heating mat or cable, thermostat, fitting under tile or laminate — the low-cost entry point for a bathroom or kitchen |
| Wet, new build or extension | £70–£100/m² | Pipe loops laid before the screed goes down — no existing floor to disturb |
| Wet, retrofit into existing solid floor | £120–£190/m² | Excavation, insulation, pipework and full screed replacement |
| Whole-house wet retrofit (typical 3–4 bed) | £8,000–£20,000+ | Manifolds, multiple loops, room-by-room controls, floor prep and integration with the boiler or heat pump |
Those bands sit close together across Checkatrade, MyBuilder and specialist supplier guides despite each pricing slightly differently — a reasonable sign the ranges are real rather than one outlier's number. Low-profile overlay panels, which add as little as 15–18mm to floor height and avoid a full excavation, sit toward the top of the retrofit band per square metre but can still work out cheaper overall once the disruption and drying time of a full screed replacement is priced in.
What drives the price
Wet or electric. This is the single biggest swing factor. Electric mats are cheap to buy and quick to fit, which is why they dominate single-room jobs, but they're expensive to run. Wet systems cost more upfront because of the pipework, manifold and (usually) a heat source to feed them, but they're far cheaper to run over a heating season — the trade-off flips depending on how much floor area you're heating.
New build versus retrofit. Laying pipe loops into a floor that's being built anyway is a different job to opening up an existing one. Retrofit adds excavation, disposal of the old floor, extra insulation to stop heat being lost downward, and a full screed pour with its drying time — typically weeks, not days — unless a low-profile system is used instead.
Floor area and layout. Cost per square metre falls as the area covered grows, because the manifold, controls and labour setup are largely fixed costs spread over more floor. A single bathroom pays a premium per m² that a whole ground floor doesn't.
Floor build-up and insulation. Getting adequate insulation beneath the pipework matters more than most quotes make obvious — without it, a meaningful share of the heat goes down into the subfloor or ground rather than up into the room, which is money spent heating the earth. On a solid floor this usually means digging deeper to fit it in; on a suspended timber floor, joist depth limits how much insulation and pipe build-up can go in at all.
Controls. Room-by-room thermostats and zone valves add cost but are close to essential on a wet system, since underfloor heating's slow response makes single whole-house control impractical.
Wet or electric — which one
For one room — a bathroom, a kitchen extension, a converted outbuilding — electric is usually the sensible call. The installation cost is a fraction of a wet system, there's no manifold or pipework to plan around, and the running cost of heating one small space for an hour or two a day is modest even at electricity prices. On typical 2026 tariffs, an electric system in a 10–30m² room costs roughly £373–£1,469 a year to run, against about £134–£392 a year for the same-sized wet system on a gas boiler — a real gap, but not one that outweighs the upfront saving for a single small room used occasionally.
For a whole floor or a whole house, that running-cost gap compounds fast, and wet becomes the only sensible option almost regardless of the higher installation bill. It's also the only practical route if a heat pump is or might be the heat source, for reasons the next section gets into. My one caution from the surveying side: don't let a low headline installation price pull you into specifying electric UFH for a large area — get the annual running cost for your actual area and usage pattern before deciding, not just the per-m² install price.
Retrofit is a different job to new build
If you're extending or building from scratch, wet underfloor heating is close to the cheapest way to heat the space, because the pipework goes down before the screed rather than into it. Retrofitting into a house you already live in is a genuinely different proposition, and the price difference reflects real extra work rather than installers padding the quote.
On a solid ground floor, a full retrofit means taking up the existing floor finish and often the screed beneath it, fitting insulation, laying the pipe loops, and pouring a new screed that then needs drying time before flooring goes back down — typically several weeks for a traditional sand-cement screed, faster for a liquid screed. Low-profile panel systems, some as shallow as 15–18mm, can go down over an existing floor without that excavation and be usable within days, which is worth pricing against the conventional route on any single-room retrofit even though the per-m² cost looks higher on paper.
On a suspended timber floor — common in Victorian and Edwardian houses and much housing up to the 1930s — the constraint is different again. Joist depth limits how much insulation and pipe build-up will fit, and a void beneath the floor lets warm air escape downward unless that void is properly closed off and insulated, which can waste a meaningful share of the heat output if it's skipped. Adding thermal mass in the form of a sand-cement screed onto a timber floor adds real weight — in the order of 20kg per square metre — and on an older floor that's a structural check worth having done before, not after, the quote is accepted. This is squarely surveyor territory: joist depth, span and condition are exactly what a structural assessment picks up before it becomes an expensive surprise mid-job.
One point that's easy to miss until it's a problem on site: any floor build-up, even a low-profile system, raises the finished floor level a little. On doorways and thresholds that were already tight, that's enough to need a door trimmed — worth asking about at quote stage, not discovering on installation day.
Why it pairs so well with a heat pump
A heat pump runs most efficiently at a low flow temperature — typically 35–45°C — against the 65–75°C a gas boiler is designed to produce. Underfloor heating uses the whole floor as the heat emitter, so it can warm a room comfortably at that lower temperature; a radiator sized for a boiler often can't, which is why heat pump installers frequently recommend larger radiators, more of them, or underfloor heating as the alternative. The lower the flow temperature a heat pump has to produce, the harder it doesn't have to work, and that shows up directly in the running cost and the system's efficiency over a heating season.
That said, the Boiler Upgrade Scheme grant — £7,500 toward an air or ground source heat pump in 2026, rising to £9,000 for eligible off-gas-grid properties between 21 July 2026 and 31 March 2027 — covers the heat pump's capital and installation cost, not underfloor heating itself. If a floor's coming up anyway, it's worth costing underfloor heating into that room before the installer defaults you to bigger radiators; if it isn't, radiators sized correctly for the lower flow temperature are a sound, far less disruptive route to the same efficiency.
What I'd watch for in a quote
- Adequate insulation specified beneath the pipework or mat, not just the heating element itself — without it you're paying to heat the subfloor or the ground.
- A room-by-room manifold and thermostat layout on any multi-room wet system, given how slow underfloor heating is to respond compared with a radiator.
- Joist depth and span checked before a quote is accepted on any suspended timber floor, and written confirmation the floor can take the extra weight if a screed system is specified.
- The finished floor height change stated in writing, and whether doors or thresholds will need trimming as a result.
- Flow temperature the system is designed around if it's feeding off a heat pump, not just off a boiler — the pipe spacing and floor covering both need to suit a lower flow temperature to get the efficiency benefit.
- A manufacturer warranty on the pipework or mat (typically 10–25 years) separate from the installer's own workmanship guarantee.
Questions I get asked
How much does underfloor heating cost in 2026? Electric underfloor heating typically costs £40–£90 per square metre supplied and installed, which is why it's the common choice for a single bathroom or kitchen. Wet underfloor heating costs £70–£100 per square metre as part of a new build or extension, but £120–£190 per square metre as a retrofit into an existing solid floor. A whole-house wet retrofit for a typical 3–4 bed home runs roughly £8,000–£20,000+ once manifolds, multiple loops, controls and floor preparation are counted.
Is electric or wet underfloor heating cheaper to run? Wet systems are substantially cheaper to run over a heating season. On typical 2026 tariffs, an electric system in a 10–30m² room costs roughly £373–£1,469 a year, against about £134–£392 a year for the equivalent wet system on a gas boiler, because electricity costs several times more per kWh than gas. Electric wins on installation cost and simplicity for one room; wet wins on running cost, which matters more the bigger the area.
Can I retrofit underfloor heating without lifting the whole floor? Yes, within limits. Low-profile overlay systems add as little as 15–18mm to floor height and can go down over an existing solid floor in days rather than weeks, avoiding a full excavation and screed replacement. They cost more per square metre than a conventional retrofit screed system, but the saving on disruption and drying time often makes up for it on a room or two. A full whole-house retrofit into solid floors still generally means taking the existing floor up.
Do I need underfloor heating if I'm getting a heat pump? No — a well-sized heat pump runs perfectly well on upgraded radiators alone, and plenty do. But the two suit each other unusually well, because a heat pump is most efficient at a flow temperature of around 35–45°C and underfloor heating can heat a room comfortably at that temperature where a radiator sized for a boiler often can't. If you're planning a heat pump and a floor's coming up anyway, it's worth costing underfloor heating in before the decision on emitters gets made by default.
If you're weighing up underfloor heating — whether it's worth the extra cost on a retrofit, whether your floor can take it, or how it fits with a heat pump you're planning — that's exactly the kind of question my retrofit assessment work is for. Call 07946 618203 or get in touch and I'll give you a straight answer on your own floor before you commit to a spec.
Small print. This guide is general information, not advice on a specific property, and it doesn’t replace a proper survey and quote for your own home. Prices were researched and correct to the best of my knowledge on 6 August 2026; costs move and vary by region and property. Always get at least three written quotes, and have joist depth and floor loading checked before committing to a screed-based retrofit on a suspended timber floor.