Underfloor Heating Costs UK — What to Charge for Electric and Water Systems in 2026

Electric vs Water (Wet) Underfloor Heating

There are two fundamentally different systems, and quoting them as if they're interchangeable is the first mistake. They suit different jobs, have very different running costs, and the labour and trades involved are not the same.

Electric UFH is a thin heating element — a mat with the cable pre-spaced, or loose cable you set out yourself — laid under the floor finish and wired back to a thermostat. It's cheap to install, low-profile, and ideal for single rooms, bathrooms, en-suites and small kitchens where you want warm tiles underfoot. Running costs are high because you're paying for electricity directly, so it's rarely the primary heat source for a whole house.

Water (wet) UFH circulates warm water through a network of pipe loops embedded in screed or routed through low-profile panels. The loops connect to a manifold, which blends and distributes flow, and the manifold ties into the heat source — a gas boiler or, increasingly, a heat pump. Wet UFH costs more to install but is far cheaper to run, especially on a heat pump, and is the right choice for whole-house heating, new builds and extensions.

Quick Reference: Underfloor Heating Prices UK 2026

These are supplied-and-fitted ranges. They exclude the floor finish (tile, LVT, engineered timber) and any heat-source work. Use them as a starting point and always price off the actual floor build-up — see the factors further down.

Electric Underfloor Heating

Electric UFH is the simplest system to install and the one most tilers and bathroom fitters offer. There's no plumbing, no manifold and no commissioning of water loops — just a heating element, a floor probe and a thermostat.

Mats vs Loose Cable

Heating mats have the cable pre-attached to a self-adhesive mesh at a fixed spacing. You roll them out, cut and turn the mesh (never the cable) to fit the room, and fix them down. They're fast in regular rectangular rooms and give a predictable output per m².

Loose cable is the bare heating wire that you set out by hand at your chosen spacing, fixed with cable straps or pushed into a profiled membrane. It costs more in labour but is the better choice for awkward layouts, around WCs and basins, and where you want to vary the output across a room. In-screed cable can also be embedded in a thicker screed as a primary heat source for a single space.

Where Electric Suits

Electric is at its best in bathrooms, en-suites, cloakrooms and single rooms where the priority is warm tiles rather than whole-house heating. It's also the only realistic option in flats with no space for a manifold, or in a retrofit where lifting and re-screeding the whole floor isn't viable. Pair it with a decoupling/uncoupling membrane under tile to manage movement and avoid cracked grout.

Running Costs

This is the part customers underestimate. Electric UFH typically draws 100–200W/m², so a 6m² bathroom running for a few hours a day is a few pounds a week — fine. Heating an entire ground floor electrically, however, is expensive and will dominate the energy bill. Always set the expectation in writing: electric is a comfort heat for small areas, not a low-cost primary system. Specifying a good insulation board underneath cuts warm-up time and running cost dramatically.

Water (Wet) Underfloor Heating

Wet UFH is the system to fit when you're heating a whole house, an open-plan extension, or pairing with a heat pump. It costs more up front and involves more trades, but the running cost and comfort over a large area are far better than electric.

Manifold, Loops and Zoning

The heart of a wet system is the manifold: a brass or stainless distribution bar with a pump, a blending (mixing) valve to drop the flow temperature to the floor, flow meters per loop and actuators for control. Each room or zone is a continuous loop of plastic pipe (PE-RT or PEX, typically 16mm) run back to the manifold. Loop lengths are kept under roughly 100m to keep the pressure drop manageable, so a large room may need two or more loops. Balance the flow rates at commissioning — skipping this is a common cause of cold spots and callbacks.

Screed Depth and Build-Up

In a new build or extension the pipe is clipped to insulation and buried in screed. A traditional sand-cement screed needs around 65–75mm of cover over the pipe and is slow to react and slow to dry. A liquid (flowing) screed — anhydrite or cement-based — can go down at 40–50mm, encases the pipe better, conducts heat more evenly and is the modern default for UFH. Either way the screed adds depth to the floor build-up, which you must coordinate with the builder and the floor finish before anyone pours anything.

Tying into the Boiler or Heat Pump

Wet UFH runs at a low flow temperature — typically 35–45°C versus 60–70°C for old radiator circuits. That low flow temperature is exactly what makes it the ideal partner for an air- or ground-source heat pump, where every degree of flow temperature you can shave off improves the seasonal efficiency (SCOP). On a gas boiler the manifold's blending valve drops the temperature; on a heat pump the system is usually designed to run UFH directly at low temperature with weather compensation. Either way, get the heat-loss calculation and emitter sizing right — an undersized loop layout on a heat pump leaves a room cold on the coldest days.

Retrofit vs New Build

New build and extension work is the easy case: you set the floor build-up before construction, drop in full-depth insulation and screed, and the cost lands in the £120–£200/m² range for the wet system itself. There's no fight with ceiling heights or existing finishes.

Retrofit is where margins get eaten. The challenge is almost always height. Adding a conventional screeded system to an existing room can lift the floor by 70mm or more, which throws out door heights, skirtings, thresholds and stair bottoms. The retrofit answer is low-profile boards — routed insulation panels typically 15–25mm deep with aluminium spreader plates that the pipe clips into, finished with a thin self-levelling compound or directly tiled with a flexible adhesive. They cost more per m² (£140–£230/m² fitted) but save the dig-out and re-screed, and they react faster because there's less mass to heat. Where ceiling height genuinely won't allow any build-up, electric mats under tile may be the only realistic option — price the trade-off honestly rather than promising a wet system the floor can't take.

Insulation Under the System — Don't Skip It

This is the single most important detail and the one cut-price installers leave out. Without insulation underneath, a large share of your heat goes downward into the slab or the ground instead of up into the room. The floor takes far longer to warm, the running cost climbs, and on a heat pump the efficiency falls because you're effectively heating the foundations.

Specify a proper insulation layer beneath both electric and wet systems — rigid PIR/EPS board in new screeded floors, and the insulating backer that comes with low-profile retrofit panels or a dedicated insulation board under electric mats. The Building Regulations on new and refurbished floors will usually dictate a minimum anyway. Quote it as a visible line item and explain what it does — it protects you from a "why is my bill so high" callback months later.

Floor Finishes and Tog Ratings

The floor finish sits between the heating and the room, so its thermal resistance — its tog rating — directly affects how well the system performs. The lower the tog, the more heat reaches the room.

• Tile and stone: the ideal finish — very low tog, high thermal mass, fast to transmit heat. The first choice for UFH.
• LVT and engineered timber: fine for UFH provided the manufacturer approves it and the combined floor build-up stays under roughly 2.5 tog. Check the spec — and acclimatise timber before fitting.
• Carpet and underlay: usable only if the combined tog is low (typically under 2.5). A thick underlay plus carpet can insulate the heat away entirely — flag this with the customer before they choose a finish.

Always confirm the finish is rated for UFH and that any adhesive or membrane is too. A cracked tile floor or de-bonded LVT over UFH is an expensive, avoidable callback.

Controls, Zoning and Smart Thermostats

Controls are where you add value and where comfort actually lives. Each heated area should be its own zone with its own thermostat, wired through a wiring centre that fires the manifold actuators and brings on the heat source when there's a demand.

Smart, Wi-Fi-connected thermostats — Heatmiser neoStat, Nest, tado° and similar — let the customer schedule and control each room from a phone, and they handle UFH's slow response with optimum-start logic so a room is warm by the time it's needed. They're a straightforward upsell: explain that radiant floors take longer to react than radiators, so good scheduling is what keeps the home comfortable without wasting energy. Price each zone as a clear line so the customer sees the per-room value.

Running Costs Compared

Customers ask "what will it cost to run" on every job, so be ready with a straight answer:

• Electric UFH: highest running cost — you pay the full electricity rate for every kWh. Excellent for a bathroom an hour or two a day; expensive as a whole-house primary heat.
• Wet UFH on a gas boiler: moderate running cost, similar to a well-set-up radiator system but more comfortable because the heat is even and low-temperature.
• Wet UFH on a heat pump: the cheapest to run over a whole house. The low flow temperature lets the heat pump hit a high SCOP, so each unit of electricity moves several units of heat. This is the combination to recommend for new builds and serious retrofits.

What Affects the Quote

Two UFH jobs of the same floor area can differ by thousands. Before you commit a price, price these in:

• Floor build-up and height: screed versus low-profile, and whether doors, thresholds and stairs need adjusting. This is the biggest swing factor on retrofits.
• Screed type and drying time: liquid screed dries faster but still needs a controlled commissioning warm-up before tiling — typically a week per 25mm before first heat, then a gradual ramp. Build the wait into your programme so you're not blamed for a delayed floor.
• Number of zones and loops: more rooms means more thermostats, actuators and manifold ports, and longer commissioning.
• Access and the work area: a clear empty extension is quick; lacing pipe through a furnished, occupied house is not.
• Heat source and electrics: whether you're tying into an existing boiler, a new heat pump, and what wiring and a spur the controls need.
• Insulation requirement: thickness driven by the floor type and Building Regs.

How to Quote Profitably and Avoid Callbacks

UFH callbacks are almost always one of three things: a cold zone from un-balanced loops, slow warm-up from missing insulation, or a cracked or de-bonded finish from skipping the membrane or the right adhesive. All three are designed out at quoting and commissioning stage, not fixed afterwards.

Survey the floor build-up properly, confirm the finish is UFH-rated, specify insulation as standard, and price commissioning and a documented warm-up as part of the job rather than an afterthought. Itemise the system, the manifold and controls, the insulation and the screed separately so the customer sees exactly what they're buying and can't compare your thorough quote against a competitor's bare number. A short one-page system summary with your quote — zones, loop layout, finish spec, warm-up programme — sets you apart and protects you if anything is queried later.

Finally, keep track of which jobs and which marketing actually pay. UFH leads come from a mix of extension builders, heat pump installers, tilers and direct homeowner enquiries — and they're not all equally profitable. Logging each quote and won job in Trade2Base shows you which sources bring the work that makes money, so you spend your time and marketing budget where the paid jobs come from rather than guessing.