The ultimate guide to underfloor heating

Last updated: 15 October 2020

In this guide you’ll get answers to the following questions:

  • How does underfloor heating work?

  • What are the pros and cons of underfloor heating?

  • Where should I place underfloor heating in my home?

  • How much does electric underfloor heating cost?

  • How do I install an underfloor heating system?

How does underfloor heating work? 

The principle is simple: heat rises, so by placing the heating elements underneath your floor, the heat rises into the room and up through your home. Some systems use piped-in water (‘wet’ systems), others electric coils (‘dry’ systems). Both wet and dry systems usually place these pipes or coils on top of a separate layer of insulation to ensure the heat is directed upwards into your home. Systems are connected to your hot water boiler or mains electricity supply, while a thermostat regulates temperature.  

What are the pros and cons of underfloor heating? 

There are plenty of reasons to give underfloor heating a try, but this type of system isn’t for everyone. Here are the main advantages of underfloor heating: 

  • Comfort and warmth

You’ll enjoy room-wide warmth in winter months with heated floors. Thanks to the fact the floor itself is heated, walking around in bare feet – even on tiled or hardwood floors – is far more comfortable.

  • Better heat distribution

Underfloor heating distributes warmth evenly throughout a room – unlike radiators, which can be patchy, creating warm and cold spots.

  • Save on energy bills

‘Wet’ underfloor heating is more efficient than traditional radiators and fires, helping to reduce both your energy costs and carbon footprint.

  • Increased home value

An efficient central heating system already boosts home value by 9%, according to some estimates. Underfloor heating not only ticks this box, but also adds a sense of luxury that homebuyers love. 

  • Better use of space

With no need for radiators in the room, you’ll have clean lines to work with and an increase in wall space. You’ll be able to fill these gaps with furnishings, kitchen units or storage. 

Of course, this type of system isn’t for everyone. Here are some of the drawbacks associated with underfloor heating: 

  • Messy installation

If you’re installing underfloor heating in an older home, you’ll experience some upheaval to your daily routine. Floors will need to be removed to install the coils or pipes, and the whole process can get messy. 

  • Initial cost

Although you’ll save money on your heating bills over time, you will be out of pocket for the initial installation. Electric underfloor heating systems can be a reasonably straightforward DIY project, but you’ll need to pay the professionals to install water-based systems. 

  • Heating times

Underfloor heating is brilliant when it comes to heating the entire room evenly, but it does take a little longer for the whole room to warm up. Fortunately, systems come with a timer so you can set it to work when you need the heat most.

What about underfloor heating vs. radiators?

Underfloor heating has the potential to be more efficient than radiators when it comes to heating your room – up to 30% more efficient in the case of a wet system; note, however, that electric systems tend to be more expensive to run. Underfloor heating also distributes heat more evenly throughout the room for a more comfortable environment. Radiators do tend to heat up more quickly, so you’ll need to adjust your timings to compensate. They’re also cheaper and easier to fit. 

Where should I place underfloor heating in my home?

You could install underfloor heating throughout the entire home, but many people will save it for ground-floor rooms, bathrooms, and kitchens. It’s easiest to install at the same time as new flooring, which makes it a popular option for house extensions and conservatories. The type of flooring you have in each room also impacts whether it’s a good idea to install it or not:

Floor typeSuitability
HardwoodSolid wood flooring is usually not compatible with underfloor heating, but engineered wooden boards are a good fit. These are crafted with multiple layers of wood, making them less prone to movement when exposed to changes in temperature or humidity.
CarpetedIf you already have thick carpeting, you may not notice the benefits of underfloor heating as much as you would with materials like tiles and laminate wood. However, underfloor heating is fully compatible if the carpet and underlay’s thermal resistance is below a 1.5 tog rating.
Stones and tilesNatural materials like slate and terracotta are quite popular in modern homes. Their thickness will determine whether underfloor heating is worthwhile – with thicker flagstones, it will take longer for the room to heat.

What types of underfloor heating are there?

There are two main types of underfloor heating systems: electric-based (or ‘dry’), and water-based (or ‘wet’).

Dry systems operate using a network of wires placed under your floor. Some use heating mats to cover large areas of the floor space, while others will operate with an intricate network of individual wires. A layer of insulation sits underneath the wire network, forcing the heat generated up into the room.

The other option is a water-based system, consisting of a network of pipes connected to your hot-water boiler. Installation is a bit trickier (and messier) with this type of system, and as a result, costs tend to be higher since you’ll need to call in the plumber. However, wet underfloor heating systems are 30% more efficient than radiators, distributing heat evenly at a lower temperature.. 

How much does electric underfloor heating cost?

There are many factors that go into determining your underfloor heating cost, including the type of system you install, how many rooms you’re fitting, and the size of your home. For example, you could expect to pay approximately £5,000 for a wet underfloor heating system throughout a new build property. Room by room, wet systems cost about £20-£30 per square metre, not including the extensive fitting costs. 

Electric systems start at around £100 per square metre for individual wiring, while heating mats are cheaper (DIY stores sell 5m2 mats for under £100 for example). You’ll need to add the cost of insulation materials and controllers as well as professional installation costs if you’re not doing it yourself. Electric systems are usually cheaper to install, but they can be up to 40% more expensive to run than wet underfloor heating systems. 

How do I install an underfloor heating system?

As with underfloor heating costs, the type of system determines how it’s installed. You can opt to install electric systems yourself, but water-based systems are best handled by a qualified plumber. 

For electric systems, choose from mats or loose wires to suit your floor space. In bathrooms or small rooms, mats will easily do the job and are quite easy to install. You simply lay them out across the smooth floor, with insulation placed above and below as needed. Loose wired systems can be distributed across larger floor spaces. Their primary benefit is flexibility, working with unusual shapes or layouts. In this case, it’s important to space the wires evenly or you’ll have some patches which are warmer than others. 

Wet systems are more complicated. You’ll need to install a network of pipes, connect these to your boiler, and potentially raise the flooring to fit everything in. Even with an electric system, it’s a good idea to hire a qualified electrician to connect the wires to your main supply. 

What are the best electric underfloor heating tips?

No matter which type of system you choose, there are a few key differences between underfloor heating and radiators. Consider these tips to make the most of your system. 

  • Get the timing right

Heating a room takes longer with this type of system, though once the room’s been warmed it will stay comfortable despite any drafts. If you set the system on a timer to go on for a couple of hours in the early morning, your room will stay warm throughout the day. 

  • Place the controls in a convenient location

Anticipate controlling your system from a central location. Many of the latest models work with apps, allowing you to control each zone from your smartphone. Although each room will need its own valve, you can place these in a central cupboard for more convenient control purposes. 

  • Combine with insulation

Insulation and underfloor heating go hand in hand, as they work together to create a more energy-efficient home. Don’t skimp on insulation below your system, or the heat will radiate downwards and be less efficient. If you’re living in an older, single-glazed property, underfloor heating may not be enough to keep the home warm – look to upgrade your windows otherwise you may need to combine it with radiators, leading to greater heating costs.

Does gas underfloor heating exist?

If you install a wet system, connected to your hot water boiler, the floor will be heated using the same system as that which heats your hot water – which can be gas or electric.

Is an underfloor heating system a good investment?

Although underfloor heating is more efficient than a radiator system, it’s still more of a luxury than a money-saving measure. According to the Energy Saving Trust, wet underfloor heating only saves £20 throughout the year – you’ll have to wait quite a while to make back the cost of installation. The greatest value for money comes with new-build homes or extensions, where you don’t have to remove existing flooring. 

Yet despite its costs, there are many benefits to underfloor heating. You’ll enjoy warmth beneath your feet, as well as a more evenly, efficiently heated room. While radiator heat dissipates when a window is opened, heated floors retain warmth for longer. It also offers a sleek, luxurious look within your home. Without radiators, you can maintain clean lines which is always a plus for those who enjoy minimalist interiors. 

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Published on Wed 23 Oct 2019 03.30 GMT