Wet versus electric — which is right for your project
Wet underfloor heating circulates warm water through PEX-A or PE-RT pipework laid in a screed (typically 65–75mm of liquid screed over insulation), connected to a manifold and the property's primary heat source (boiler, heat pump or community heat network). Wet UFH suits large floor areas (15 sqm and above), is highly efficient with heat pumps (operating at 35–45°C flow temperature ideal for ASHP COP), and is the preferred system for ground floors in new builds and major renovations. Electric underfloor heating uses thin heating mats or cables under tile or stone, controlled by a thermostat. Electric suits small rooms (typically under 12 sqm), is fast to install (no screed cure time, no plumbing chase), and avoids the 50–80mm floor buildup that wet UFH requires — making it the go-to for retrofit bathrooms where existing floor levels cannot be raised.
What the installed price includes
A typical London wet UFH installation at £55–£85/sqm covers: the floor insulation board (typically 50mm PIR or similar), edge insulation, the heating circuit pipework (PEX-A with oxygen barrier), the manifold and zone actuators, thermostats and zone wiring, the liquid screed pour and cure (typically calcium sulphate flowing screed, 7–14 days cure), commissioning and balancing. It does not cover the floor finish (tile, engineered wood, stone) or any preparatory works to existing substrates. Electric UFH at £35–£60/sqm covers the heating mat, insulation underlay, sensor cable, programmable thermostat, electrical connection to a Part P notifiable circuit and a final tile bedding allowance. Add £200–£400 per zone for premium thermostats with smart controls (Heatmiser, Honeywell Evohome, Nest).
Running costs and efficiency in 2026
Wet UFH is significantly cheaper to run than electric UFH because gas, heat pumps and heat networks all deliver heat at a lower energy cost than direct resistance electric heating. On a 100 sqm wet UFH ground floor with a heat pump at typical London winter usage, expect 3,500–5,500 kWh/year for space heating at a 2026 standard tariff of around 7–10p/kWh (heat pump time-of-use): roughly £350–£550 per year for the UFH heat load. The same area on electric UFH would consume 7,000–10,000 kWh on the heating circuit at peak time-of-use of 28–35p/kWh: easily £2,000–£3,500 per year. The trade-off: wet UFH costs £5,500–£8,500 more to install on 100 sqm but pays back the difference in 3–5 years at current energy prices. Electric UFH remains the right choice for small bathrooms used briefly — running cost is negligible because the area is small.
