Underfloor heating costs in the UK: wet vs electric compared
Underfloor heating comes in two genuinely different forms — wet (water-based) and electric — and the right choice depends heavily on what you're actually trying to achieve, since the two systems differ substantially in both upfront cost and how much they cost to run.
Electric underfloor heating works by running a heating cable or mat beneath the floor surface, warmed directly by electricity. It's commonly the cheaper option to install, typically running around £40-£120 per m² depending on the product and complexity of the installation, and because the cable or mat is relatively thin, it's often practical to retrofit into an existing floor without major structural work — a common reason it's popular for a single-room job such as a bathroom renovation, where a full wet system would be disproportionate. A typical bathroom retrofit of around 4-6m² commonly costs somewhere around £750-£1,600 fitted, a scale where electric systems tend to make the most practical sense.
Wet underfloor heating instead circulates warm water through a network of pipes beneath the floor, connected to a boiler or heat pump rather than running directly off electricity. It's generally more expensive to install, commonly around £70-£190 per m², partly because it involves more substantial pipework and often needs a manifold and additional plumbing work, and is generally more disruptive to retrofit into an existing floor since it usually needs more floor buildup than an electric mat. For a whole-house installation — commonly quoted for an 80-120m² three-bed property — a wet system typically costs somewhere around £6,000-£13,000 supplied and fitted, reflecting the larger area and more involved installation.
Running costs tell a different story, and this is where the two systems' relative appeal can flip depending on how you weigh upfront versus ongoing cost. Figures published in 2026 put electric underfloor heating running costs at around £2.90 per hour for a whole floor, against around £2.10 per hour for a wet system, which annualises to a meaningful difference — roughly £2,646 a year for electric against around £1,916 for wet, based on these figures, though actual costs depend heavily on your specific electricity and gas or heat pump running costs, insulation, and how much of the year the heating is actually needed. In broad terms, electric systems are usually cheaper to install but more expensive to run, while wet systems cost more upfront but are usually cheaper to run over the long term — which is why the "right" choice depends heavily on scale and how long you plan to be in the property to recoup the higher upfront cost of a wet system.
This running-cost pattern is also why the two systems tend to suit different scenarios in practice, beyond simply room size. Electric underfloor heating suits smaller areas and retrofits well precisely because the higher running cost per m² matters less when it's only heating a modest bathroom or kitchen floor for part of the day, and the lower installation disruption and cost make it the practical choice for adding heating to a single room in an existing home. Wet systems suit whole-house installations, particularly in a new build or full renovation where the floor buildup can be planned in from the start, and make particular sense when paired with a heat pump — heat pumps generally run more efficiently at the lower flow temperatures a wet underfloor system needs, compared with the higher temperatures a radiator system typically demands, so combining the two is a common and sensible pairing for a new heating system.
When comparing quotes for either system, check what's included beyond the raw heating element cost — a wet system quote should typically cover the manifold, pipework, floor insulation (needed to direct heat upward rather than losing it downward into the subfloor), and a compatible thermostat and zoning setup; an electric system quote should specify the mat or cable product, a suitable thermostat, and any floor levelling compound needed before installation. As with most home heating decisions, getting a couple of like-for-like quotes covering the same scope of work is the most reliable way to see whether a price reflects the actual job.
Frequently asked questions
Electric is generally cheaper to install, commonly around £40-£120 per m², compared with around £70-£190 per m² for a wet system; a typical bathroom retrofit with electric heating commonly costs around £750-£1,600 fitted.
Wet underfloor heating is generally cheaper to run over time — figures published in 2026 put wet systems at around £2.10 per hour against around £2.90 per hour for electric, though actual costs depend on your energy prices, insulation and how much heating is used.
Electric is usually the practical choice for a single-room retrofit such as a bathroom, since it is cheaper and less disruptive to install into an existing floor, even though it costs more to run per hour than a wet system.
Yes — wet underfloor heating runs at lower flow temperatures than most radiator systems, and heat pumps generally achieve higher efficiency (a higher SCOP) at these lower temperatures, making the pairing of a heat pump with wet underfloor heating a common and sensible combination, particularly in a new build or full renovation.