Underfloor heating costs: From installation to running costs, here's what you can expect to pay

Underfloor heating provides a discreet and effective replacement for conventional radiators, and has grown in popularity among homebuilders and renovators.

This heating solution not only makes your house feel cosy and uniformly heated, but it also improves energy efficiency, which could result in cheaper heating costs. Nonetheless, underfloor heating costs are a crucial factor for anyone wishing to install it.

A number of different factors are taken into consideration when estimating the cost of underfloor heating, such as the type of system being specified, the size of the space that has to be heated, floor finish, the difficulty of installation, and any extra parts or adjustments that are needed.

Here heating expert David Hilton, and quantity surveyor Tim Phillips, explain all the underfloor heating costs you need to consider.

Underfloor heating costs vary depending on the type of system

Underfloor heating systems can be broadly classified into two systems: water-based (wet) systems and electric (dry) systems and each different type comes with various costs associated with it.

It's also worth bearing in mind that underfloor heating installation can be cheaper in new builds and extensions, as it can be designed in and planned for from the outset. Whereas in existing homes, it often necessitates the removal or lifting of existing floor finishes and potentially work to the subfloor.

Despite the initial cost, underfloor offers comfort under foot, while also freeing up the wall space that may have previously been taken up with different types of radiators.

It also adds the opportunity to heat large open-plan areas as well as rooms such as bathrooms and kitchens where appliances and cupboards take up much of the wall area, leaving very little opportunity for the installation of heating emitters.

Through thorough evaluation of the system type and your property's unique requirements, it means you can make an educated choice that strikes a balance between up-front and ongoing expenses.

Electric underfloor heating costs

Installed under the floor, either in tailored panels or films or in the screed, electric underfloor heating is essentially electric wires whose resistance heats the floor, so warms the space.

Installing an electric system can cost between £27 and £95 per square metre depending on the size and type of system. Depending on the complexity of the installation and the particular needs of the property, the costs may differ considerably.

Potential floor height modifications and insulation, which is essential for optimising efficiency, are additional costs to take into account.

Most electric underfloor heating systems require insulation boards to minimise warm-up times and also reduce running costs, in some cases by 25%. Expect to pay around £10 for a 1200 x 600 x 10mm board. Boards come in various thicknesses from 6mm up to 50mm for differing flooring situations.

You will also need to factor in the costs of your chosen underfloor heating thermostat and a typical digital 16amp will cost around £80. Your electrician will also need to connect up the power supply and sign it off. For a typical house, expect to pay between £250 - £320/day for an electrician or plumber.

Electric underfloor heating installation is a great option for smaller spaces or individual rooms because it is typically less expensive and simpler to install.

However, there are five main types of electric underfloor heating systems: cable, mesh, foil electric, matting and loose wire. Each comes with its own set of costs.

1. Cost of mesh electric UFH systems

Expect to pay around £54/m2 to £80/m2.

The thinnest system (best suited to tiled surfaces), this type of electric underfloor heating has wires that are attached to a thin mesh and the whole product is less than 2mm thick. The floor levels are not raised as the tile adhesive is then applied directly onto the mesh and the heater then effectively sits in the adhesive layer.

2. Cost of matt electric UFH systems

Expect to pay around £64/m2 to £95/m2.

For fast installation, a system with a matting can be used that decouples the tiles from the subfloor. The matting is laid on the floor and the wires are pushed into preformed rebate cut-outs.

The adhesive is then applied to the matting and as it is not applied direct to the subfloor potential future seasonal cracking risk is also mitigated.

3. Cost of foil electric UFH systems

There is no requirement for a screed with this type of solution and you can expect to pay around £54/m2 to £85/m2.

Soft finishes such as carpets, vinyl and laminate as well as other floating floors can sometimes be a challenge and foil type systems are designed for this scenario. For more information on this, it's worth taking a look at our guide on underfloor heating with carpet or wooden flooring with underfloor heating.

4. Cost of loose wire electric UFH systems

Expect to pay around £64/m2 to £95/m2.

If the room has irregular shapes or permanent fixtures then a loose wire system is best suited to it. The heater is a durable, but flexible, cable that is stuck to the backing boards and is embedded in the levelling compound or adhesive. Installation is a bit more detailed but the product allows for a lot more design layout variation.

5. Cost of cable electric UFH systems

Expect to pay around £27/m2.

The cheapest electric underfloor heating system is a cable that is bedded in a screed. This system has thicker wires and allows for floor finish changes and screed thickness changes without damaging the wires.

The system is also slow to react and should be designed for long-term space heating and not for quick task heating for short periods of time.

Is electric underfloor heating costly to run?

The running costs of electric underfloor heating can vary depending on how much you pay for electricity, the capacity of the heating system per square meter and how long you leave it on for. In terms of running costs, it is generally costlier than water-based systems, which might add up in the long run for bigger areas. That said, it’s ideal for retrofit situations or locations where installation height is a factor.

As an example, electric underfloor heating can cost circa £0.50 for a 4m2 bathroom with a 195W/m2 system which runs for three hours a day. So this could equate to around £15 each month. Look at the cost calculator on www.thermosphere.com to see running costs for your situation.

The simple facts are electricity currently costs about 24.5p per kilowatt hour (kWh). Therefore if your electric underfloor heating is 125W per square meter then for every 8 square meters of floor you will use 24.5p per hour that the system is on.

Look at the cost you are paying as well as the cost that you may be paying in the future and check the time of any off-peak tariff and also make sure that you actually do have spare capacity from any solar panels if you are calculating them into the equation.

It is also worth bearing in mind that the system is not on all day as the thermostat will only call for heat when it is required. The exact number of hours that it is on will depend on the efficiency of the room that the heating is in but if you need a rough estimate then use 50%, and probably less in a new build.

Wet underfloor heating costs

There are two main types of water-based underfloor heating systems: buried pipe and surface-mounted pipe. They are usually more costly and intricate to install than electric systems, frequently necessitating significant alterations to the flooring and the heating system already in place.

The costs for installing a water-based system will depend on the type of build situation — is it a newbuild or deep renovation for example. In most cases, the underfloor heating company should include the design, pipes, thermostats, controllers, and underfloor heating manifolds and connectors in their quotation as well as the installation.

Budget for material costs of £55 to £80/m2 for an average house, if you’re thinking of carrying out any install works on a DIY basis. If you think you'd prefer to leave it to a professional installer, the Warmup website suggests you can pay anything from £100 - £300 a day for an installer, and that an area of 40m2 will take around 2-3 days to complete.

“People tend to think underfloor heating is reserved for the rich but it’s really not. Our system currently retails at £42/m2 excl VAT. That means that installing underfloor heating across the ground floor of a three-to four-bedroom house, with a floor area of 55m2, would cost in the region £1,800 to £2,500,” comments Sam Jump, Head of Business Development, for Wunda Group. “Add to that the fact it can be easily DIY’d and you’re also cutting down on installation costs.”

Both systems will also require a separate heat source, so that could be a conventional combi-boiler, an air source heat pump or ground source heat pump if you are considering using renewable energy. In addition to this you will have to include costs for a manifold and pump/mixing valve unit pack.

A small room requiring only a two-port manifold starts at £100 with a more complex 12 port costing £375. A pump and mixing unit will be on average £250.

1. Buried wet UFH

Pipes can be clipped to your insulation boards and the screed can be laid over them embedding the pipes in the screed. The pipes can be in parallel lines across the floor or in a circular shape depending on the shape of the floor.

The pipes can also range between 10mm and 16mm diameter with the larger pipes being the most effective but also requiring more installation space.

The cost of the pipework will vary depending on the quality of the pipe and the lengths used. As it is not good practice to have joins in the pipe loops there can be quite a bit of wastage if the loops are not carefully planned.

2. Surface-mounted wet UFH

On a joist type floor, such as first floors, underfloor heating pipes can be installed under the floorboards by either fitting them from the room below (before the ceiling is fitted), or by notching the joists and installing the pipework before fitting the floorboards.

Another method is to use an ‘overlay’ system where the pipes are fitted into a preformed board that has rebated grooves for the pipes to be pushed into. The groves are preformed at around 150mm centres (for 16mm pipe) and has a thickness of around 20mm.

Smaller bore pipes will have the grooves closer together and the boards may also be a bit thinner. The boards are often made of high density polystyrene but there are also wood fibre boards, plastic boards and heavier composite boards. As with any additional changes you are making to the structural elements of the home you will need to make sure that any additional weight of the system or notching of beams is within the structural tolerance of the materials.

Is wet underfloor heating expensive to run?

While the initial outlay in installing wet underfloor heating is often more expensive, in the long run a wet system is typically cheaper to run than an electric underfloor heating system.

The real expense is how much energy the home needs. If the room requires 500W to keep it warm then you will want to optimise the way the heat is delivered to the water in the system.

If you use direct electric then it will be around three times more expensive than heat pumps or a gas boiker. The direct electric heater may cost around 17p per hour but a heat pump or gas boiler should be under 6p per hour.

Maintenance costs

Even though underfloor heating systems don't require much maintenance, it's still necessary to plan ahead to make sure they stay functional and efficient. With proactive maintenance such as yearly inspections, recurring flushing for water-based systems, and timely repairs, when necessary, homeowners can extend the life of their underfloor heating system. Here are some factors to consider:

• Annual service – A professional's yearly inspection may assist guarantee that your underfloor heating system is functioning well and can spot any possible problems before they get out of hand. Regular maintenance usually costs around £180, depending on the system's size and complexity.
• Flushing water-based systems – Periodic flushing of water-based underfloor heating systems may be necessary to get rid of any buildup or sludge that could be affecting the system's performance. Usually, this is advised every five to 10 years. Although the price to flush a system can vary, it usually costs £350.
• Repairs and spares replacement controls and thermostats – Depending on the type and features, replacing a failed thermostat or control unit might cost anywhere between £50 and £200.
• Water-based systems: pumps and valves – These parts may eventually need to be replaced due to wear and tear and can cost anything from £100 to £300, not including labour.
• Modifications and reassessments - To make sure the system is performing at its best, it might occasionally need to be recalibrated. Typically, this service is less costly, ranging from £40 to £80.
• Unexpected problems - Issues such as leaks in water-based systems or electrical faults in electric systems can occur, though they are uncommon. Timely resolution of these issues is essential to avert more harm. The price range is wide; small repairs may run up to £100, while more serious problems may end up costing several hundred pounds.

FAQs

Which is more expensive: Underfloor heating or radiators?

The simple answer when it comes to underfloor heating vs radiators is that it very much depends on your home, project and product.

When it comes to installation, adding radiators can be fairly simple compared to adding underfloor heating. There's far less disruption to a room, and a radiator can often be fitted simply where there is wall space (piping can be more tricky but still relatively straight forward). They are also quick and inexpensive to fit.

Adding any kind of underfloor heating meanwhile will require total upheaval of the flooring, which is usually expensive when retrofitting underfloor heating. This is certainly true when it comes to wet underfloor heating, making installing radiators far cheaper.

Building a new home or extension, however, provides an opportunity to design in and install underfloor heating from the outset.

When it comes to running costs, wet underfloor heating, if it is installed with good insulation in a well-insulated home can be more energy efficient than radiators. At most, it is estimated to be around 25% more efficient than radiators.

That does differ for electric underfloor heating systems as the cost of running this very much depends on the unit price of electric, which is often far higher. The same of course applies for electric radiators.

The final consideration is longevity and maintenance. Radiators are easily accessible and therefore easier to access to maintain. Underfloor heating meanwhile, if it goes wrong will often require the floor to be dug up. That said, radiators have a lifespan of up to 10 years, while underfloor heating is claimed to have a lifespan of up to 50 years.

Can I install underfloor heating myself?

DIY installation of underfloor heating can be a cost-effective option for those with the necessary skills. This could involve some of the simple labour-intensive works like cutting and laying the insulation boards, applying adhesive, or fitting the matting or wire system.

However, it's crucial to consider the complexity of the project, the need for compliance with building regulations, and the potential impact on warranties and insurance. You would in most cases still require an electrician and/or a plumber to carry out final connections i.e., thermostats and manifolds.

This approach ensures a reliable and efficient heating system, providing peace of mind and long-term savings.

Want to make sure you get the right flooring on top of your underfloor heating? Read our guide to the best flooring for underfloor heating and if toasty toes after bath time is your main objective, find out more about underfloor heating in bathrooms.