Underfloor heating has moved from a luxury specification to a mainstream consideration in UK renovations and new builds — and the question of what it actually costs is one of the most frequently misanswered questions in residential construction. The figures vary widely, the comparison between electric and wet systems is rarely made on a like-for-like basis, and the hidden costs — insulation, floor preparation, floor build-up, controls — are routinely absent from the headline numbers that first attract buyers. This guide sets out the complete picture.
Key Takeaways
- Electric UFH costs £60–£120 per m² installed in 2026, making a standard bathroom (4–5m²) a £240–£600 project and a medium kitchen (15m²) a £900–£1,800 project — affordable for single rooms, less economical for large areas.
- Wet (hydronic) UFH costs £70–£190 per m² installed — new builds at the lower end (£70–£120), retrofits significantly higher (£95–£190) due to floor preparation, insulation work, and structural coordination.
- A full-property wet UFH installation typically costs £3,000–£13,000, with larger or more complex projects exceeding this range.
- Installation cost is only part of the picture — insulation boards, floor build-up, manifold, controls, and floor covering compatibility all add to the project cost and must be budgeted explicitly.
- New build vs. retrofit is the most significant cost variable — installing during construction is substantially cheaper than retrofitting into an existing property, where floor preparation, levelling, and disruption dominate the additional cost.
- Running costs strongly favour wet systems for large areas — at current energy prices (electricity ~27p/kWh; gas ~6.9p/kWh), wet systems connected to a gas boiler are approximately four times cheaper to run per unit of heat; heat pump-connected wet systems narrow this gap further.
- The payback period is real but long — the higher installation cost of wet UFH over radiators is typically recovered in energy savings over many years, making it most compelling in new builds and major renovations where the system is designed in from the outset.
The Two Systems: What You Are Actually Comparing
Any cost discussion about underfloor heating requires first establishing which system is being discussed, because the economics of electric and wet (hydronic) UFH are sufficiently different that comparing them without context produces meaningless figures.
Electric UFH uses resistive heating elements — cables or mats — embedded in or beneath the floor finish. Electricity passes through the element and generates heat directly. The system requires no boiler, no pump, no manifold, and no primary pipework. Installation is a job for a tiler and an electrician. It is the simpler, cheaper-to-install option; it is the more expensive option to run for large areas over sustained periods.
Wet (hydronic) UFH circulates hot water from a boiler or heat pump through plastic pipes embedded in or below the floor. The system requires a manifold, a circulator pump, pipework connecting the manifold to the heat source, and a system of zone controls and thermostats. Installation involves heating engineers, often a screed layer, and significant floor preparation. It is the more complex, more expensive-to-install option; it is the cheaper option to run for large areas over sustained periods.
The choice between them is not primarily a question of taste — it is a question of area, application, project type, and long-term ownership horizon.
Electric UFH: Installation Costs in Detail
In 2026, the average supply and installation cost for electric underfloor heating is £85 per m², with prices typically ranging from £60 to £120 per m².
These figures include both the heating mat or cable and the installation labour. They do not always include:
- The thermostat: A basic programmable thermostat costs £50–£150; a Wi-Fi connected smart thermostat costs £100–£250. At least one thermostat per circuit is required.
- Electrical supply circuit: Each electric UFH zone requires a dedicated circuit from the consumer unit. In a bathroom or kitchen, this requires a Part P registered electrician. The circuit cost depends on proximity to the consumer unit and whether additional capacity is required.
- Insulation boards: Installing insulation beneath the heating element dramatically improves efficiency by directing heat upward rather than allowing it to dissipate through the subfloor. Insulation boards add £10–£25 per m² but can reduce running costs by 25–40%.
- Floor preparation: In a retrofit, lifting existing flooring and preparing the subfloor adds cost that varies significantly by the existing floor construction.
By room type (electric, supply and installation, 2026):
| Room type | Area | Cost range |
|---|---|---|
| Small bathroom / en suite | 4–5 m² | £240–£600 |
| Standard bathroom | 6–8 m² | £360–£960 |
| Medium kitchen | 15 m² | £900–£1,800 |
| Large open-plan kitchen/diner | 30 m² | £1,800–£3,600 |
Wet UFH: Installation Costs in Detail
Wet underfloor heating costs between £100 and £190 per m² to get installed by an experienced professional in 2026. New builds or straightforward screed floors often come in at £70–£120 per m²; retrofits into existing properties typically range from £95–£190 per m², reflecting extra floor preparation, insulation, levelling, and coordination with existing structures.
These installed costs include:
- UFH pipe (typically 16mm PEX-a or PEX-b pipe at 150–200mm centres)
- Manifold assembly (including actuators, flow meters, and mixing unit)
- Circulator pump
- Insulation board beneath the pipes
- Screed or levelling compound over the pipes (where specified)
- Zone controls and thermostats
- Labour for all of the above
They typically exclude:
- Primary pipework from the heat source (boiler or heat pump) to the manifold location — which adds cost depending on the distance and the complexity of the route
- Boiler upgrade — if the existing boiler is not compatible with UFH flow temperatures or lacks the output capacity for the additional load, replacement adds approximately £2,000–£4,000
- Floor covering — the cost of tiles, timber, or any floor finish is always separate
By project type (wet system, supply and installation, 2026):
| Project type | Area | Cost range |
|---|---|---|
| Single room, new build | 15–20 m² | £1,050–£2,400 |
| Ground floor, new build | 50–80 m² | £3,500–£9,600 |
| Single room, retrofit | 15–20 m² | £1,425–£3,800 |
| Ground floor, retrofit | 50–80 m² | £4,750–£15,200 |
| Whole house, new build | 100–150 m² | £7,000–£18,000 |
Most full-property installs land somewhere between £3,000 and £13,000, depending on total floor area, room layout, insulation requirements, and whether retrofitting.
The Hidden Costs: What Gets Left Off the Quote
The gap between a headline installation figure and the total project cost is one of the most consistent sources of budget surprise in UFH projects. The following categories should be explicitly included in any budget:
Insulation: UFH requires adequate insulation beneath the heating element to minimise heat loss downward and maximise heat directed upward. For ground floors, this is typically 50–100mm of rigid PIR (polyisocyanurate) insulation board. For upper floors, 50mm boards are standard. Insulation cost: £15–£35 per m².
Screed: Wet UFH in a screed installation requires a sand-cement or liquid screed to cover the pipes, provide thermal mass, and create the finished floor substrate. Sand-cement screed: £15–£30 per m² (self-levelling liquid screed is more expensive but faster and achieves better flatness). Screed curing time: typically 28 days for sand-cement, 7 days for some liquid screeds, before floor coverings can be laid.
Floor build-up: Adding 75–100mm of screed and 50mm of insulation to a ground floor adds 125–150mm to the floor level — which requires door frames, skirting boards, and sometimes staircase risers to be adjusted. This structural adaptation can add significant cost in retrofit projects.
Floor covering compatibility: Not all floor coverings are compatible with UFH. Carpets must have a combined tog rating (carpet plus underlay) below 2.5 — most thick carpets and carpet with thick underlay exceed this. Solid timber (rather than engineered) is generally not suitable for wet UFH. Floor covering specification can narrow significantly in a UFH project.
Controls and thermostats: Beyond the basic thermostat at each zone, a central heating control system (wireless or wired) that integrates UFH zones with the rest of the heating system adds cost. Smart multi-zone controllers that integrate with apps and smart home systems: £300–£800.
System commissioning and balancing: A wet UFH system must be filled, purged of air, and have the manifold flow rates balanced for each circuit — all before the floor covering is laid and before the system can be used. This commissioning is typically included in a specialist UFH installer’s quote but may not be included in a general plumber’s quote for the same installation.
Running Costs: The Long-Term Picture
Installation cost is one half of the economic equation. Running cost is the other, and for UFH it is strongly influenced by system type, fuel type, room insulation, and how intelligently the system is managed.
Electric UFH running costs:
At winter 2026 Ofgem cap electricity rates of approximately 27p per kWh, a system’s power output — for example 150W/m² — multiplied by the hours of use and the electricity rate determines the daily cost.
For a practical example: a 6m² bathroom heated at 150W/m² (900W total) for 2 hours per day costs approximately 49p per day at 27p/kWh — approximately £15 per month in the depths of winter. For a 30m² kitchen heated at 150W/m² for 6 hours per day, the cost rises to approximately £3.65 per day — £110 per month in winter. This is why electric UFH works well in bathrooms and single-purpose rooms but becomes expensive in large, continuously heated spaces.
Wet UFH running costs:
For most well-designed water systems, annual bills are up to 30 percent lower than with radiators, provided zoning and insulation are used. Water UFH is 15–30% more efficient than radiators when paired with a condensing boiler.
In a well-insulated 40m² family kitchen-diner, running costs can hover around £25 to £45 per month through winter, depending on insulation and heat source efficiency. Wet underfloor heating costs around £2.10 per hour to run, or around £1,916 per year, compared to electric at around £2.90 per hour or £2,646 per year.
The heat pump advantage:
Heating a 60m² home at 35°C flow temperature with a modern system and heat pump might cost £10–£14 per week, versus £15–£30 per week with traditional radiators. The heat pump’s COP (coefficient of performance) — producing three or more units of heat for each unit of electricity consumed — changes the economics of electric generation fundamentally. UFH is the ideal heat emitter for a heat pump because it operates at the low flow temperatures that heat pumps achieve most efficiently.
New Build vs. Retrofit: The Cost Multiplier
The most significant variable in UFH installation cost is whether the system is going into a new building (or a building stripped back to its structure) or being retrofitted into a finished home.
New build advantages:
- Pipes or mats are installed before screeds are poured — no lifting of existing floors
- Insulation is designed into the floor build-up from the outset — no floor level implications to manage retroactively
- Primary pipework routes from heat source to manifold locations are planned — no chasing through finished walls
- Manifold locations are positioned during construction with adequate space and access designed in
- The overall project cost per m² is lower because the installation is unimpeded
Retrofit challenges and costs:
- Existing floor coverings must be lifted
- Existing screed or timber floors may need breaking out or building up
- Floor level is raised by the insulation and screed build-up — door frames, skirting, and stairs may need modification
- Primary pipework must be routed through a finished building — chasing, boxing, or compromising on route
- Disruption to the property during installation can be significant — furniture must be removed, rooms made unusable
For these reasons, wet UFH is most cost-effective when planned as part of a major renovation or new build. Electric UFH — because it requires no screed and no primary pipework — remains a practical retrofit option for single rooms even in a finished property.
Is Underfloor Heating Worth the Investment?
The investment case for UFH depends on the application:
New build ground floor with wet UFH: The clearest case. The system is installed at relatively low incremental cost (the insulation and screed are part of the construction programme regardless), the comfort benefit is significant, the running cost is lower than a radiator system, and the property value premium is real. UFH is the expected specification in quality new builds and its absence is noticed by buyers.
Bathroom electric UFH retrofit: A strong case in almost all circumstances. The installation cost is modest, the running cost impact is small, the comfort improvement is immediate and lasting, and the absence of visible radiators in a bathroom is both aesthetic and practical. Bathroom UFH is one of the highest-return comfort upgrades available.
Ground floor retrofit with wet UFH: The most demanding case to make. The installation cost is substantially higher than new build equivalents, the disruption is significant, and the payback period in running cost savings is long (typically ten or more years). The decision is most appropriate when the retrofit is happening as part of a broader renovation that already involves lifting floors.
Whole-house wet UFH, new build: A premium specification that adds measurable property value, delivers ongoing running cost savings (particularly with a heat pump), and produces a level of comfort — even, draught-free warmth at lower air temperatures — that a radiator system cannot replicate. At the scale of a whole-house installation, the economies of scale bring the per-m² cost toward the lower end of the installed range.
UFH is not the right answer for every application, and the installation costs are real and significant. But in the applications where it is genuinely right — a bathroom refresh, a new-build ground floor, a major renovation that is lifting floors anyway — the combination of comfort, energy efficiency, and property value makes it one of the more defensible significant home improvement investments available.
