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, so the build-up height and how the pipes or mats go in are what make or break the budget. The real prices on this page come from retrofit projects, so they show the real-world cost of adding warmth underfoot to a home that is already finished rather than a bare shell.
The quick version
- Retrofit costs hinge on how much floor height you can spare. Low-profile systems that sit on top of the existing floor are quicker and cheaper than digging out and re-screeding.
- A wet system fed by your boiler or heat pump usually suits whole rooms and long-term running costs, while electric mats suit small or awkward spaces like a bathroom.
- As an energy-saving measure, underfloor heating carries 0% VAT until 2027 in many cases, which is worth checking with your installer before you agree a price.
- Any electric underfloor heating must be connected by a Part P registered electrician to meet building regulations, so factor that into who you hire.
- Whether the room sits on a solid slab or a suspended timber floor changes the whole approach and the price, so it pays to know which you have before getting quotes.
- The finished floor going back on top, tiles, engineered wood or vinyl, affects both cost and how well the heat comes through, so it is worth discussing with the fitter rather than deciding separately.
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, since timber floors often suit a different retrofit system than a concrete slab. 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 still living in the house. Who you hire matters too. A sole trader working alone will price a job differently from a larger heating and plumbing firm with a team and overheads, and labour rates are not the same everywhere in the country, so where you live shapes the quote as much as the spec of the system itself.
How to pay less
- Choose a low-profile overlay system where floor height allows, since 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 rather than into the joists or slab below 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, since the cheaper option is not always obvious until you compare.
- Ask whether the 0% VAT rate for energy-saving measures applies to your job before you sign anything, since it can make a real difference to the final bill.
- Prioritise the rooms where it matters most, such as a bathroom or kitchen floor, rather than doing the whole house at once if budget is tight.
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, such as under a door threshold, 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 or a single kitchen floor. The real prices on this page show both so you can compare for your space rather than guessing.
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 and price the job on that basis rather than on assumptions.
How much disruption should I expect during the work?
That depends almost entirely on whether the floor is coming up. A low-profile overlay system can sometimes be fitted in a day or two with minimal mess, while a full dig-out and re-screed means the room is out of action for longer, including drying time before the floor finish goes down. Ask your fitter for a realistic timeline before you agree a price so you can plan around it.
Does the type of finished floor affect the price?
Yes. Tiles and stone conduct heat well and are a natural match for underfloor heating, while thick carpet or certain wood floors can insulate against the heat and need a more powerful system to compensate. Tell your fitter what floor covering you want before they quote, since changing your mind afterwards can mean redoing part of the job.
Is it worth doing one room now and the rest later?
It can be, especially if budget or disruption is the concern. Doing a bathroom or kitchen first lets you spread the cost and see how the system performs before committing the whole house. The trade-off is that some fixed costs, like the fitter's setup and any manifold work, may not scale down proportionally for a single room.