How is underfloor heating powered?
Underfloor heating uses the basic principle of waves of heat rising through the air. Underfloor heating can be either a 'wet' system that pumps warm water (usually heated via a gas boiler) through pipes under the floor, or 'dry' system of electric coils placed under the floor which heat up when the system is turned on.
Below, we'll take a look at the pros and cons of underfloor heating, the different types of underfloor heating systems available, how to install them and the costs involved.
What are the pros and cons of underfloor heating?
As is the case with everything in life, underfloor heating has pros and cons that have to be taken into consideration when making the decision to opt for it or not.
Comfort - that sense of luxury is amplified when you're able to walk around in bare feet during the winter months
Increased heat efficiency - not only is heat distributed evenly around the room, but a system which is big enough to heat the whole room will be a more efficient method of heating than a radiator, so your energy bills could come down
Increased home value - underfloor heating is an extremely desirable feature for home buyers, so any property which includes it (even if it's just in one room) will be worth more when the time comes to sell
Installation - it's possible to install electrical underfloor heating systems yourself and, as we've already seen, it works particularly well with tiles and stone, which makes it a popular choice for bathrooms.
Cost - it can cost a lot to have the system installed, as well as creating a lot of upheaval throughout the installation process. This makes it particularly suitable for new-build properties or when you are already having work done on your floor
Time to heat and room layout - an underfloor heating system will take longer to heat a room, so it is vital to combine it with a timer so you have the heat when you actually want it. The systems can also restrict what you can place on the floor as they can’t sit under particular fittings and items of furniture
Installation - if you're opting for a water-based system, you'll need to pay for professional installation rather than trying to do it yourself.
Electric underfloor heating systems
Electric underfloor heating systems rely on a network of wires under the floor that heat up. Depending on the shape of the room, you can opt for heating mats which cover large areas, or individual wires which can get in every nook and cranny. Heating mats are generally a bit cheaper as they are a uniform size. The wires usually sit on top of a layer of insulation. They can fit under different floor types (but shouldn’t be under carpets that are too thick - a tog rating over 1.5 is generally classified as too thick). The electric wires themselves are fairly thin, making them easier and cheaper to install than a water-based system. However, they are also slightly pricier to run, making them better suited to smaller areas.
Water underfloor heating systems
Water underfloor heating systems, in contrast, are a network of pipes linked to your boiler that pump hot water around the room. Because underfloor heating systems distribute heat more evenly than radiators, they actually use water at a lower heat than a radiator. This ensures that your boiler is more efficient.
The difficulty with water-based systems is based around the installation, and costs are typically initially higher for this reason. Unless you're a professional plumber, it's inadvisable to try and install the system yourself. Pipes are thicker than wires, so there needs to be enough room in your floor for the system to be installed, or the ground may need to be slightly raised. This means that while they’re a great solution for new builds, they can be difficult to install on some properties.
Consequently, installing a water-based system is not easy and, unlike electric systems, shouldn’t be installed without assistance.
Can you get gas underfloor heating?
Water-powered underfloor heating systems are usually powered by gas boilers, so they're one and the same.
However, because they're powered by gas, they should work out cheaper overall than electric systems once installation has been completed. As of October 2024, electricity costs 24.50p per kWh while gas costs 6.24p per kWh. However, this only covers energy costs - water costs will also have to be factored in.
How to install underfloor heating systems
The type of system you install will depend on the type of floor you have, with different types available for different surfaces. Electric underfloor heating systems can generally be installed yourself, cutting the overall cost.
When it comes to a water-based system, it's best not to attempt to install it yourself - hire a plumber to handle it for you, because installation will require laying the pipes, connecting them to the boiler system and possibly even raising the floor.
How much does it cost to install underfloor heating systems?
Underfloor heating cost depends entirely on what system you opt for and whether you install it into a new-build (or install at the time of renovating an existing property) or not. An electric system will cost around £75 per square metre for pre-fitted underfloor heating mats, or £100 per square metre for the loose cables. Further costs come in the form of insulation to lay under the system, heating controls and electrician fees.
Water-based systems will cost significantly more, with total costs after installation running into thousands of pounds.
Is underfloor heating worth it?
It's important not to be under the illusion that underfloor heating is a money-saver - it depends on the surface area you're working with as well as your fuel source and this, coupled with the substantial installation costs, means you are unlikely to save much.
However, because the majority of costs come from installation, underfloor heating can be ideal when building a new-build home, or building a new room, bathroom or extension. The main attraction for underfloor heating is comfort. The way both types of system heat a room mean not only will your feet be warm, but the heat will be more evenly distributed and consistent.
For example, if you have a stone floor with underfloor heating built in, the heat will be retained, even when the window is open. Compared to the way radiator heat dissipates the second a draft enters a room, that can be an attractive proposition. It also provides a very clean and minimal look. A bathroom with underfloor heating has no additional clutter created by bulky radiators, and the value of the house will be improved through adding it.
