Underfloor heating guide: how it works, benefits & costs
What Is underfloor heating and how does it work?
There are two types of underfloor heating: wet (hydronic) and electric. Wet systems – the type we install and recommend at Roost Heating – pump warm water through a network of pipes laid beneath the floor. Because the whole floor becomes the heat source, warmth radiates evenly upwards into the room rather than from a single point like a radiator.
Wet systems typically run at a flow temperature of 35–45°C, compared to 70–80°C for a standard radiator system. That lower operating temperature is the main reason underfloor heating is more efficient – and why it pairs particularly well with heat pumps, which perform best at lower flow temperatures.
Electric underfloor heating uses a mat of resistance wire instead of pipes. It’s cheaper to install and better suited to small areas like a single bathroom, but more expensive to run than a wet system, so it’s rarely the right choice for a whole house.
Underfloor heating vs radiators: what are the real benefits?
- Lower running costs. Because underfloor heating operates at a lower temperature and heats a room more evenly, homes can see heating bills fall by up to 20% compared to a radiator-only system.
- More even, faster warmth. Radiators heat the air immediately around them first, and it takes time for warmth to spread. Underfloor heating warms the entire floor, so the room reaches a comfortable temperature more evenly and heat loss from cold spots is reduced.
- Low maintenance. Once installed correctly by a qualified installer, a wet underfloor heating system can last the lifetime of the building with no regular servicing needed.
- Better air quality. Radiators circulate air (and the dust in it) as they heat. Underfloor heating doesn't create the same convection currents, and the warm, dry floor is also less hospitable to dust mites - a genuine benefit for allergy sufferers.
- More usable room space. No wall-mounted radiators means no compromise on furniture layout, and no radiator taking up wall or floor space.
- Flooring choice stays flexible. Underfloor heating works under tile, wood, laminate and carpet, so you don't have to redesign your room around it. (Carpet and underlay with a combined tog rating above around 2.5 will reduce efficiency, so it's worth checking with your installer.)
- Safer for young children. No exposed hot surfaces, sharp radiator edges, or fittings for curious hands.
Is underfloor heating worth it?
For most homes, yes – but the answer depends on three things: how well insulated the property is, whether you’re retrofitting into an existing floor or installing during a renovation/new build, and how long you plan to stay in the property.
Retrofitting into an existing home used to mean raising the floor significantly, but low-profile systems now add as little as 15mm, making underfloor heating realistic for most renovations, not just new builds. The upfront cost is higher than a like-for-like radiator replacement, but the ongoing savings, added comfort, and appeal to future buyers usually make it a worthwhile investment – particularly if you’re already lifting the floor for a kitchen or bathroom refit.