DATA-BACKED GUIDE · UPDATED JULY 2026
Retrofit underfloor heating cost in an existing house
Fitting underfloor heating into a house you already live in is a different job from laying it in a new build, and the price reflects that. You are working around existing floors, doors and skirting, which means the build-up height and how the pipes or mats are laid make or break the budget. The real prices below come from retrofit projects, so they capture the real-world cost of adding warmth underfoot to a home that is already finished.
The quick version
- Retrofit costs hinge on how much floor height you can spare, since low-profile systems are quicker than digging out and re-screeding.
- A wet system fed by your boiler or heat pump usually suits whole rooms, while electric mats suit small or awkward spaces.
- As an energy-saving measure, underfloor heating carries 0% VAT until 2027 in many cases.
- Any electric underfloor heating must be connected by a Part P registered electrician to meet building regulations.
What people actually paid
Real prices, in people's own words
- £1,100“just paid Wunda around £1100 for the components for our GF UFH. this includes a Grundfos pump station, 11 port manifold, perimeter insulation strip, pipe staples, around 1200m of 16mm pipe and the required isolation valves.”
- £1,100“pricing as above I did mine £1100 most my bits came from Outsourced Energy”
- £1,200“The UFH kit (pipes, manifolds, actuators, stats, control unit etc) came in at £1200 (supply only, we self-fitted). We did get a quote of £500 for someone else to fit it for us.”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
The biggest cost driver in a retrofit is what you have to do to the existing floor. If there is room to lay a slim overlay system on top, the job stays tidy and quick. If the floor has to come up so pipes can sit in fresh screed, you are into far more labour, muck away and drying time, and you may need doors trimmed and skirting refitted afterwards. Whether the room sits over a solid slab or suspended timber changes the approach again. Room size, the number of rooms, insulation boards underneath and the type of finished floor going back on top all feed the final figure, as does how disruptive the work is while you are living there.
How to pay less
- Choose a low-profile overlay system where floor height allows, as it avoids the cost of digging out and re-screeding.
- Bundle the work with a floor you were replacing anyway so the disruption and prep are only paid for once.
- Insulate under the pipes properly. It pushes heat upward and keeps running costs down for years.
- Get three quotes and ask each fitter to price both a wet and an electric option for the space.
Common questions
Can you retrofit underfloor heating without lifting the floor?
Often yes. Low-profile overlay boards and slim mats sit on top of the existing floor and add only a small amount of height, which avoids the mess and cost of excavating. Where you have no height to give up, the floor may still need to come up.
Is wet or electric better for a retrofit?
Wet systems tend to win for whole rooms and long-term running costs, especially with a heat pump, while electric mats are cheaper to install in small rooms like a bathroom. The real prices below show both so you can compare for your space.
Will underfloor heating replace my radiators?
In a well insulated room it often can, giving you back the wall space. In a poorly insulated or very large room you may still need some background heat, so it is worth a fitter checking the heat loss before you decide.