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Underfloor heating explained

Underfloor heating costs and installation

By Liz Ransome-Croker

Article 4 of 4

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Find out how much underfloor heating costs, how it will affect your home and what to expect from a typical installation.

How much you pay for underfloor heating varies dramatically depending on which type you choose, whether it will be installed in a new room or retrofitted to an existing room, and what your floor structure is like.

To make sure you don't end up paying more than you should for underfloor heating, or make a choice that you later regret, we've done the hard work for you. 

We've contacted underfloor heating installers and companies across the UK, including The Underfloor Heating Store, Warmup Plc, Polypipe and independents, to find out what you should expect to pay and what you need to consider. 

You can use the findings from our research to choose the right type of underfloor heating for your home and budget, and to make sure you don't get caught out by any unexpected costs.

We've also spoken to members who have underfloor heating to get their tips on what to think about when buying and having it installed*. We've asked what they wish they had known and what they would have done differently, so you'll know exactly what to expect and can avoid annoying or costly mistakes. 

Click on the links below to jump straight to the section you want.

Types of underfloor heating

There are two types of underfloor heating: electric and water.

  • Electric underfloor heating is cheaper to buy and have installed. You can even install some of it yourself, although you'll need a qualified electrician to connect it.
  • Water underfloor heating is cheaper to run than electric systems, but it's more expensive to install and it's advisable to get professionals to do it. Water systems are more efficient than electric systems, especially in a larger room.

Underfloor heating costs 

When we spoke to independent installers and companies across the UK (in 2014), we asked how much it would cost to:

  • retrofit electric underfloor heating in a small bathroom (4.5 square metres)
  • install water underfloor heating in a large new-build extension (37 square metres, well insulated and an empty shell).

We also asked members and underfloor heating owners how much it cost them to have their system installed. 

If you're a Which? member, you can log in now to unlock our findings, expert advice and tips from underfloor heating owners. 

You'll also get access to our member-only advice on the pros and cons of getting underfloor heating, where you can read about the real benefits and drawbacks from people who have it and live with it – day in, day out.

Not yet a member? Join Which? to get instant access to all our advice on heating, from underfloor heating to wood-burning stoves, and reviews of appliances including boilers, washing machines and vacuum cleaners.

What can affect the price 

Find out what can hike the price of underfloor heating by logging in or joining Which? to ensure you get what you want for the best price.

Underfloor heating installation process 

Log in or join Which? to unlock our expert advice on what happens during an underfloor heating installation, from industry experts and owners.

Can you install it yourself? 

Log in or join Which? to unlock our expert advice.

Can you fit underfloor heating in old houses? 

Yes you can – underfloor heating can be fitted in any house. However, in properties with low energy efficiency, for example those with single glazing and no insulation, it's unlikely that it will be able to act as the only form of heating. You'll probably need to have central heating and radiators as well. The size and cost needed to run it might be prohibitive, too.

However, if you have additional work carried out to improve how well the house retains heat, such as loft insulation and modern glazing, it could be much more effective.

Do you need planning permission? 

In most cases, no. However, if your home is a listed or a historically significant property, it's worth checking your plans with a qualified surveyor or architect.   

If you're putting the underfloor heating into a new room, work will need to conform to building regulations. 

What type of flooring is best for underfloor heating? 

Most types of flooring are fine to use on top of underfloor heating, including vinyl, laminate and tiles. But some, such as stone, are better as they are natural heat conductors. This means the floor will feel warm more quickly, and the warmth should stay longer. 

However, if your heart is set on a particular type of flooring, your installer should be able to adjust the underfloor heating system output, the underlay and type of screed to suit the floor type. You can find a recommended installer by visiting Which? Trusted Traders.

Wooden flooring

If you have real wood floors, it's worth checking with the manufacturer what the maximum temperature is that the wood can take – it's typically 27°C. Temperatures that are too high can warp and shrink the flooring, especially if the moisture content of the wood is high.

Engineered wooden or laminate floors are a much better choice if you don't want to run the risk of problems in the future, but want the look of wood. However, it shouldn't exceed a maximum thickness of 18mm, as this will reduce the efficiency of your system.

Carpet

Although carpet is not the most efficient floor covering on top of underfloor heating, as it will take time for the heat to get through, it can still be done. To get the best out of it, keep the combined tog value of the underlay and carpet below 2.5.

Concrete

If you like the modern loft look and want exposed concrete floors, make sure you don't use this to encase the underfloor heating system. Both water and electric systems should be installed within screed, not concrete, as sharp aggregate can damage the system.

It's also worth keeping in mind that concrete will take longer to warm up, but will retain the heat for longer.

What type of boiler do you need for underfloor heating? 

Water systems will work with any type of boiler, including condensing, wood or vented. In fact, they will work with any type of heat source, such as a heat pump. 

The system will be connected to the heating via a manifold (see image below). Electric systems, on the other hand, only need to be connected to your electrics.

When we called installers across the UK and water underfloor heating, some mentioned needing to get a new, more efficient central heating system. If this is suggested to you, make sure you get a few opinions before going ahead. 

If you're thinking about getting a new or different central heating system, it might be worth considering a ground or air-source heat pump, as these run at lower temperatures (50°), which is an ideal temperature for underfloor heating.

Visit our full guides to ground-source heat pumps and air-source heat pump to learn more and to see whether they might be right for you.

As well as using Which? Trusted Traders to find an underfloor heating installer, you can search for certified gas-safe heating engineers to advise you.

Underfloor heating tips 

When we spoke to underfloor heating owners about their experiences, there were a few key areas that kept cropping up.

 Log in or join Which? to unlock their advice so you don't make the same mistakes or have the same frustrations.

*(In November 2017 we surveyed 104 Which? members with underfloor heating about their experiences with it in the last five years. All quotes and comments are from when we spoke to 177 people in August 2015)

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