Underfloor heating: how it works and costs to buy and run
By Stephen Marcus Tuesday 08 December 2020
It’s not hard to see the appeal of underfloor heating. After all, who wouldn’t want to make the winter months more cosy with lovely warm feet? Plus, if you opt for it throughout the house, it can even remove the need for radiators. That means more space for artwork, shelf units – or perhaps even a bold new minimalist look!
There are a few different options, and choices – such as whether you want to have it in just one room, or throughout your home. It really depends on what kind of home you have, and how much you’re willing to spend. In this guide, we’ll walk you through the different kinds of underfloor heating, how much they cost to install and run, and how they actually work.
What is underfloor heating? Why should I choose it?
Simply put, underfloor heating warms your home through a system installed beneath your flooring – as opposed to the radiators most of us are familiar with. Aside from the wonderful feeling of having warm floors, it distributes heat very evenly through your home. And depending on your home, and the type of system you choose, it could make your home more energy efficient – and it can also reduce your carbon emissions.
For more on lowering your energy use, check out our ultimate guide to being efficient with heating and hot water.
Benefits of underfloor heating
Here are some of the top perks of underfloor heating:
Toasty warm feet! You can walk around barefoot all year. Making stepping out of the bath or shower heavenly!
It distributes heat evenly and consistently around each room.
A suitably sized unit can heat a larger area than an individual radiator, and works at a lower temperature, so it could reduce your heating bills
Less waste – your floors will stay warm, even if the windows are open or the room is draughty.
It’s hidden – so it doesn’t spoil your décor or take up space with bulky radiators. (But if you do want to get your radiators working at their best in the meantime, check out our guide on how to bleed a radiator.)
It can be installed below stone, tile, wood, or carpeted floors (as long as the carpet isn’t too thick - a 1.5 tog is generally considered the maximum suitable thickness).
It can make your home more hygienic – a warmer floor temperature is inhospitable to dust mites. So you’ll have warmer feet and fewer creepy crawlies!
The disadvantages of underfloor heating
The main problem with underfloor heating is the cost. It can be expensive, and difficult to install – so even if your bills are lower, you’re unlikely to recoup your initial outlay.
In older buildings, adding underfloor heating can take time and cause major upheaval.
It can take a long time to warm up – so it’s vital to use a timer, to make sure your rooms are warm enough when you want to use them.
You can’t use it under some items of furniture or fittings. In fact, if you want to install underfloor heating, you might have to get rid of some large, heavy items altogether.
If you use a smaller system, you may find you have a lovely warm floor but the rest of the room is still chilly – meaning you’d need radiators anyway.
Types of underfloor heating: wet vs dry systems
There are two types of underfloor heating:
Electric underfloor heating
As the name suggests, an electric system uses electricity to warm your floors via heating cables fitted underneath. There are three choices for ‘dry’ systems:
Loose wire – best suited for stone or tile floors, and ideal for awkward-shaped rooms
Matting – great for stone or tile floors, and for large or more regular-shaped rooms
Foil mat – designed specifically for laminate flooring
Water underfloor heating or wet system
Wet systems connect to your central heating system via a network of pipes running hot water beneath your feet. Here’s the basics:
Any kind of boiler can be used, as long as it has sufficient capacity
The water is pumped through pipes laid on to a sub floor, before the new surface is added on top
The system uses continuous plastic pipes, so there are no joints – which means no leaks!
What’s the ideal temperature for underfloor heating?
As ever, this varies depending on your home and your preferences – but for most people the ideal temperature is around 21°C for living areas, and 18°C for bedrooms. Check out our handy infographic to get a better idea of the perfect temperature for each room of your home.
Is underfloor heating actually too expensive?
It depends. One big consideration is whether you’re building a new home or renovating an existing one. Generally speaking, it will cost more when you’re retrofitting underfloor heating in an existing home. The other factor is whether you’re installing a wet or dry system.
Underfloor heating cost in a new build
A wet system will typically cost between £5,000 and £7,000 to install in a new build1.
For a wet system, specialist companies like Nu-Heat or FloRad offer an all-in service.
Underfloor heating cost in a renovation
It’s harder to say how much a renovation would cost, as it depends on how much floor lifting is needed, and other potential complications. As a guide, the system itself costs £20 to £30 per square metre.
It’s almost always cheaper to install a dry system. Prices for roll-out mats for underfloor electric heating start at about £170 for 10 square metres2. Plus, you’ll need to add in the costs of insulation board, screed and heating controls. You’ll also need to pay a qualified electrician to link it to your electricity supply.
The price of installing a wet system can vary. If it’s just one room, then it depends on whether it’s on the ground floor, or how close it is to the boiler. However, it will almost certainly be more expensive than installing an electric system.
How much does underfloor heating cost to run?
In most cases, there will be a big difference between the heating costs of a wet and dry system.
Warm water underfloor heating running costs
While it might be expensive to install, underfloor heating is usually the cheaper option to run. It’s typically more efficient than an electric system, meaning that you can run it for less.
Electric underfloor heating running costs
Dry systems can be a lot more expensive to run – sometimes up to 3 or 4 more times more than a wet system. This is in large part because electricity tends to cost more than natural gas. For this reason, it’s often used to heat single rooms, like bathrooms or kitchens.
If you want to keep your electricity usage down, check out our guide to reducing electric bills.
Check out our guide to energy saving tips for more advice on how to bring down your energy usage at home. And if you want to learn about other environmentally-friendly ways to heat your home, head to our article on the best low carbon heating options.
What type of flooring is best for underfloor heating?
As you might expect, materials like stone are best suited to underfloor heating – as they’re natural heat conductors, warming up more quickly and keeping the heat for longer. But it’s possible to use most types of flooring, including vinyl, laminate and tiles.
Whichever type of flooring you’re after, it should be possible to arrange your system to suit your needs. Here, we go through some of the key things to consider.
Real wood floors need extra care. It’s worth checking the maximum temperature the wood can handle with the manufacturer. It’s usually around 27°C. Anything above that, and the heat can cause the wood to warp and shrink.
Engineered or laminate floors can be a good option for a wood feel without the risks. The only thing to bear in mind is to ensure it’s not too thick – ideally no more than 18mm – otherwise it will affect the efficiency of your system.
To get the best results with carpet, you don’t want it to be too thick. The thicker the carpet, the longer it will take to warm up. For this reason, the combined tog of the carpet and underlay should be below 2.5.
For many, concrete is the perfect flooring for a sleek, modern interior. And the good news is that it’s well-suited for underfloor heating, because it retains heat for a long time.
One important thing to remember is to avoid encasing the underfloor heating system itself in concrete. Both water and electric systems should be installed within screed, not the concrete, which can damage the system.
Other questions to consider when installing underfloor heating
Can you fit underfloor heating in old houses?
Yes – but it’s worth considering if it’s the best option. If you have an old house with poor insulation, or single glazing, it will probably still need to be combined with a traditional radiator system.
If your home has low energy efficiency, and you still want to install underfloor heating, it could be worth doing alongside renovation work such as installing insulation, and energy-efficient doors and windows. It’s also worth looking into the Green Homes Grant to see how you could get help to pay for this.
You could also think about DIY insulation quick-fixes such as making your own sausage dog draught excluder. Taking these types of steps would all help to bring down the cost of running your system.
For more information about insulation, check out the wide range of guides and tips on our Content Hub.
Do you need planning permission?
Unless you’re lucky enough to live in a listed building or historically significant property – the answer is probably no. If it’s going into a new room, then you’ll need to make sure it conforms to building regulations.
How long does underfloor heating take to warm up?
Depending on your flooring and the kind of system you have, it can take 2 or 3 hours to warm up. This is because the screed around the heating pipes takes a while to conduct the heat up through the floor and warm the air.
Should I leave underfloor heating on all the time?
In colder months, it can work best to leave underfloor heating on at a low temperature throughout the day. Because of the time it can take to warm up, this means your home will be heated faster when you need it.
Do I need a timer?
Ideally, yes. You’ll need to set it to come on a good while before you need it.
Have you thought about smart thermostats? They can help you control your heating from anywhere, while also reducing your bills. Read our guide to find out more about the benefits of smart thermostats and why you should get one.
Can I install it myself?
If you’re confident with DIY – then yes! It’s possible to install an electric system yourself – but if you’ve opted for a water system, you’ll need to hire a professional.
For either system, an electrician will need to connect both your system to the electricity supply, and a sensor for the thermostat.
How else can I make my home warmer?
Insulation is key. Insulate your roof and walls and you could save around £250 a year3. What’s more, you’ll cut your home’s carbon emissions by around 1.5 tonnes – which means you’ll be helping the planet, too.
Some other top tips include:
Fill that cavity! Cavity wall insulation can cut around £115 off your heating bill each year4.
Get draught excluders for outside doors, windows and letterboxes.
Replace all your old windows with double glazing – it could save you around £120 each year5.
If your boiler’s more than 15 years old, look into replacing it with a new A-rated condensing boiler. Check out our practical guide to help you choose the right boiler for you.
How can I cut my energy costs?
Underfloor heating installation is expensive – so you may want to find other ways to save on your energy bills. To start with, make sure your home and all your electrical appliances are working as efficiently as possible. Here are some suggestions:
When you boil a kettle, only use as much water as you need
Turn appliances off at the wall – don’t leave them on standby
Defrost your freezer regularly
Slip an insulating jacket on your hot water tank – you could save around £35 a year
When using your washing machine, never set it higher than 30˚. Read our guide to energy-saving white goods.
See if you could save money by repairing or replacing your boiler
See our full guide to energy-saving for more details, and iour explainer on how to use your heating efficiently during the winter.
It also makes sense to consider switching suppliers. No matter which energy company you’re currently with, we recommend you check the market regularly to see if you could save money by switching. You can get a quote on a plan with OVO in seconds.
We know that price matters – and that’s why we offer competitively-priced 100% renewable electricity as standard. We also plant a tree for every year you’re with us. And you'll also get up to 3% Interest Reward on any credit in your account.
See how your current supplier matches up next to our range of energy plans. Compare prices for our electricity, gas and dual fuel plans.
Sources and references