A guide to underfloor heating

There are different pros and cons to this style of heating, from cost to efficiency. If you’re trying to decide whether to ditch radiators for underfloor heating, this guide will walk through everything you need to know to help you find out if it’s worth it for your home.

What is underfloor heating?

Underfloor heating, sometimes shortened to ‘UFH’, is exactly what it sounds like: a heating system that’s installed beneath your floor.

Traditional wall-mounted radiators heat a room mostly by creating a convection current, heating the air nearest to them, which then rises, cools and sinks, moving the warm air around the room.

On the other hand, UFH works by turning your entire floor into one big, gentle radiator. It uses radiant heat, which warms objects and people in the room directly, rather than just heating the air.

This method gives a more even and consistent temperature from the ground up, which eliminates the cold spots in your home that you often get with radiators.

How does underfloor heating work?

UFH systems are all hidden from view by flooring, but operate in one of two main ways: either by using electricity or by using water.

Electric underfloor heating

Electric UFH systems, also known as ‘dry systems’, use a series of electric wires or pre-laid heating mats that are installed under your floor covering. When the system is switched on, an electric current flows through these wires or mats, which heat up and radiate warmth upwards into the room.

These systems are connected to your electricity supply and are controlled by a dedicated thermostat. This thermostat is often a smart, programmable unit that lets you set precise temperatures and heating schedules.

Because the mats and wires are very thin, electric UFH is often the go-to choice for renovation projects and single rooms, like bathrooms or kitchens, as they don’t raise the floor height significantly.

Water underfloor heating

Water UFH systems, also known as ‘wet systems’ or ‘hydronic systems’, work by pumping warm water through a continuous loop of plastic piping installed beneath the floor.

This network of pipes is connected to a central heating system, which could be a traditional boiler or a modern, renewable source like a ground-source or air-source heat pump. The water is heated and then circulated through the pipes by a pump, warming the floor and radiating heat into the room.

For both wet and dry underfloor heating, learning how to use central heating economically is key to maximising savings on your energy bills – whether electric or gas (if your wet system uses a gas boiler to heat everything up).

Which type of underfloor heating is better? Electric vs gas systems

The type of underfloor heating that’s best for you depends on your project, property and budget. Let’s compare them side by side:

Electric underfloor heating systems

Electric systems are best for smaller areas, single rooms, or retrofitting into existing properties where you don’t want the major disruption of digging up the floor.

Pros:

• Easier and cheaper installation
  The materials are typically cheaper, and installation is usually faster and less complicated than a wet system.

• Quick to warm up
  Electric wires heat up very quickly, so you’ll feel the warmth in around 30–60 minutes.

• Space-saving size
  Because the heating mats and wires are very thin, they won’t have a big effect on your floor height.

Cons:

• More expensive to run
  Electricity is typically more expensive than gas per kilowatt-hour (kWh). This makes electric UFH’s running costs higher, especially over larger areas.

• Cools down quickly
  As soon as you turn the system off, the wires cool down and the heat fades relatively fast.

Wet underfloor heating systems

Wet systems are usually the preferred choice for new builds, large-scale renovations, or whole-house installations where they’ll be used as the primary source of heating.

Pros:

• Lower running costs
  Because they typically use gas or a heat pump rather than electricity, they’re usually cheaper to run in the long term.

• Retains heat
  The flooring material that surrounds the pipes heats up and holds that warmth for a long time, even after the boiler switches off.

• Works with renewable systems
  Wet systems are the perfect partner for ground-source and air-source heat pumps, which also work most efficiently at lower water temperatures.

Cons:

• Expensive and complicated to install
  Installing a wet system involves laying and connecting a network of pipes, and often laying several layers of flooring material. This means more materials, more labour, and more cost.

• Slower to warm up
  It can take several hours for a wet system to heat through the layers of flooring, and in turn several hours to bring a cold room up to a more comfortable temperature.

• Takes up more space
  The pipes and flooring materials needed for wet systems can add a lot more height to the floor, which can be a problem in existing homes, affecting door heights and thresholds.

The verdict? For a single bathroom or kitchen renovation, electric is often the most practical choice. For a new extension, a self-build, or a complete ground-floor renovation where you’re replacing the floors anyway, a wet system could be a great long-term investment.

Is underfloor heating expensive to run?

The running costs of underfloor heating depend on which system you choose:

Running costs of electric UFH

‘Dry’ electric UFH can be expensive to run in large areas, because the running cost is directly tied to the price of your electricity tariff.

This is why electric UFH is best used in smaller, well-insulated rooms (like a bathroom) for short bursts of time. Using it to heat a bigger space, like a living room, all day would probably result in a high energy bill. To understand what else contributes to your bill, it’s worth checking what appliances use the most electricity in your home.

Running costs of water-based UFH

Water-based UFH is one of the more cost-efficient ways to heat a home. It can cover a large surface area while running at a much lower water temperature than traditional radiators, around 40°C rather than 70°C.

This lower operating temperature means your boiler or heat pump works much more efficiently, using less fuel to keep your home warm. If your boiler is gas-powered, you can learn more about managing its consumption with our handy guide on what uses gas in a house and how to reduce gas usage.

Comparing UFH with traditional heating methods

When compared to radiators, a well-designed wet underfloor heating system is more energy-efficient, potentially reducing your heating bills by up to 25%.

An electric underfloor heating system, however, is usually more expensive than running a gas-powered radiator system. It’s more comparable to the running costs of other types of electric heating, like panel or fan heaters.

For both systems, running costs can be heavily influenced by:

• Insulation - Poor insulation, whether it’s under the floor, in the walls, or in the loft, will mean heat escapes. This causes your system to work harder to keep things warm, which will cost you more.

• Room size - The larger the area, the more energy it’ll take to heat.

• Heating schedule - How long you have your heating on each day.

• Your energy tariff - The unit price you pay for your gas and electricity.

The costs of installing underfloor heating

While running costs are a long-term consideration, the upfront cost of installing underfloor heating is often the deciding factor.

Installation costs will depend on a wide variety of factors, like your type of property, location, and complexity of the job. And it’s always best to get multiple quotes from different firms to help you make an informed decision before you get stuck in.

Here’s some information from Checkatrade to give you a rough idea of what installation costs are currently like for UK homes.

New builds:

Retrofits:

As you can see, the cost of a wet system is a lot higher, especially in a retrofit situation where more preparation work is needed.

Is underfloor heating worth it?

Whether underfloor heating is worth it depends on whether the benefits outweigh the cost and disruption for you:

Does underfloor heating save you money?

It depends on the type of system: a wet underfloor heating system absolutely has the potential to save you money on your energy bills. Its high efficiency means it uses less energy to achieve the same level of comfort as a radiator system. And while the upfront cost is high, the long-term running cost savings can provide a return on that initial investment over many years.

However, an electric underfloor heating system installed throughout your home and used often is unlikely to save you money compared to a gas central heating system.

But with both systems, the real trick to saving money is pairing them with other good habits. You can find lots of ideas in our energy savings tips guide.

How to use underfloor heating efficiently

To get the most out of your system and keep running costs as low as possible:

• Use a programmable thermostat
  Particularly because of slow warm-up times for wet systems, you’ll need to program your heating to switch on a couple of hours before you need it. Programming it to the times you want makes sure your home is heated exactly when it needs to be, with no wasted energy.

• Maintain a consistent, lower temperature
  UFH isn’t designed to be turned on and off for short blasts, especially wet systems. It’s much more efficient to set it to a lower, consistent ‘base’ temperature for longer periods of time, as making it constantly heat up from cold can be inefficient and takes more energy to heat back up.

• Don’t turn it off completely
  Like the point above, it’s often more economical to set the thermostat to a low ‘setback’ temperature over the winter when you’re out or overnight, for example, 16°C. Again, this means the system only has to raise the temperature by a few degrees when you want to heat the house, rather than heat up from completely cold.

• Zone your heating
  A good UFH system will be set up in ‘zones’, with separate thermostats for different rooms or areas. This means you can choose which spaces you want to heat at a time while still having one central system.

• Understand your smart meter
  Knowing when you’re using the most energy is an important step in taking control of your usage. A smart meter can be an essential tool for this, which comes with an in-home display that lets you see your energy use in near-real time. Our complete guide to smart meters can tell you more.

• Insulate well
  There’s no point in paying to heat your floor if the heat keeps escaping – proper insulation boards must be installed underneath the UFH system to make sure all of that precious heat is radiating upwards into your room, not getting lost downwards.

Which system will you choose?

The choice between a cheaper-to-install, fast-acting electric system and a more complex but more efficient wet system comes down to your project and goals. Electric UFH is perfect for adding a touch of luxury to a single, small room, while a wet system can be a serious, long-term investment that can heat your whole home while saving you money on your energy bills for years to come.

While the upfront cost and building disruption are significant, the benefits of invisible, quiet and efficient warmth make underfloor heating a worthwhile upgrade for many UK homes.

If you’re looking to improve your home’s energy efficiency, UFH could be a great step. And if you want to pair it with a great value energy tariff, we can help with that, too.