Collage showcasing installed water underfloor heating system in spacious rooms of a private house with large windows.

Underfloor heating is one of the top choices for warming up a home in today's age, and it's even taking over the more traditional radiator. While many people swap over to this innovative system because it's sleek and modern, that's not the only reason. It's also an extremely efficient way to heat up your property, even if you're in a commercial setting, and can save you a lot in the long run.

But exactly how efficient is it? And how much does underfloor heating cost? We have all the answers for you in this comprehensive guide. Keep reading to discover more about the efficiency of underfloor heating kwh per m2 and how you can make the most of it yourself.

Key takeaways

  • Underfloor heating is highly efficient due to its even heat distribution across the floor, surpassing traditional radiators.
  • There are two main types: electric and water systems. Electric systems are suitable for singular rooms, while water systems are ideal for entire properties.
  • Underfloor heating is more efficient than traditional radiators and competes well with alternatives like air source heat pumps and geothermal heating.
  • Electric systems typically range from 100W/m2 to 200W/m2, making them suitable for singular rooms due to their higher operating costs compared to water systems.
  • Water systems have a lower wattage per square meter, typically ranging from 40W/m2 to 100W/m2, making them more energy-efficient and cost-effective in the long run.
  • While underfloor heating may have a higher initial installation cost, the long-term energy efficiency leads to significant savings compared to traditional heating systems.

Despite its underlying significance, screed is one of the most overlooked aspects of construction. Screed serves multiple functions, whether used as a protective layer for your flooring or to allow underfloor heating systems to operate even more efficiently. It currently stands as one of the most versatile materials throughout the construction industry.

This complete guide to the different types of screed, how to lay floor screed, and its advantages and disadvantages. We will uncover everything there is to know about this overlooked component, shedding light on just how important it is in construction.

How underfloor heating works

Underfloor heating systems come in different forms, with the two main ones being electric and hydronic (or water). These both work in similar ways but use different components:

Electric underfloor heating system

Electric underfloor heating systems are designed to provide heat to a property from below. Under the floors, a series of cables or underfloor heating mats. These are connected to a power source, and when turned on, they will gradually warm up in sequence and then heat up the room above. These are best recommended for singular rooms rather than for a house house/property.

Water underfloor heating system

Water underfloor heating systems work in the same way as their electric counterpart. However, instead of using cables and heating mats, they utilise pipes and tubes connected to a manifold. When turned on, warm water will flow through the series of pipes and ultimately heat up the surface area above. These are good to use throughout entire properties.

Comparing underfloor heating efficiency over other systems

Well-executed underfloor heating installation in a spacious area with panoramic windows.

So, now you know what underfloor heating is and how it works, how do these systems compare in terms of efficiency compared to other systems? Here are three we're going to look at:

Traditional radiators

Underfloor heating is undoubtedly more efficient than traditional heating methods like radiators. This is mainly because they distribute heat evenly across the floor, rather than sticking to one area of the room. These underfloor systems also operate at lower temperatures and minimise air circulation.

Air source heat pumps

Air source heat pumps (ASHPs) are a strong contender against underfloor heating in terms of efficiency. They draw heat from outside, which makes them much more eco-friendly, however, this means that they can only work at an optimal level depending on the weather. Underfloor heating can also use renewable energy, but without having to rely on certain conditions.

Geothermal heating

Geothermal heating is another alternative system that many people debate over installing compared to underfloor heating. It uses the heat from the Earth to warm up the home, which makes it much more sustainable and efficient. However, it can cost a lot more to install than underfloor heating. Some people might use both these systems together for ultimate efficiency.

Electric underfloor heating efficiency

Comparison of two underfloor heating systems, electric and water-based.

You already know how electric underfloor heating works, but how does this affect its efficiency? Overall, these systems can be highly efficient, especially when they are installed with the right insulation and controls. However, since they are still using electricity to generate heat, they aren't considered as efficient as hydronic systems and therefore are better for singular rooms because they are cheaper to install.

The electric underfloor heating kw per m2 ranges around 100W/m2 to 200 W/m2 depending on the type of system you've had installed or the possibility of heat loss in the room. You can most likely find out the exact wattage of a system when talking to a professional.

Water underfloor heating efficiency

As we mentioned, water underfloor heating systems are generally more efficient than their electric counterpart. They are considered one of the most energy-efficient central heating systems, especially when they're paid with modern condensing boilers or high-efficiency heat pumps. And while they might cost a bit more to install at first, the operating costs are much lower than radiators and electric underfloor heating, making them a great investment.

Water underfloor heating watts per m2 are typically lower compared to electric systems, with the range being between 40 W/m2 and 100 W/m2. As you can see this is much lower and efficient, but make sure to check with your engineer before having an installation.

Is underfloor heating expensive?

Collage displaying installed water heating system, its connection to hot water supply, and the final result after floor screeding.

Underfloor heating costs tend to vary depending on the type of system you're running, how it's installed, and the size of the area that needs to be warmed up. You might notice that the initial installation cost is higher than that of a traditional central heating system like a radiator. However, they offer much more energy efficiency each month, which means you have longer-term savings when using them.

As we've mentioned, electric underfloor heating systems are much more affordable when it comes to installation, however they have a higher kw per m2 number, leading to higher operating costs. Hydronic systems might cost more upfront, but you definitely end up saving more in the future.

Tips for maximising underfloor heating system efficiency

Want to increase the efficiency of your underfloor heating system even more? Here are a few tips you can follow:

  • Ensure proper insulation beneath the floor to minimise heat loss
  • Use programmable thermostats to regulate temperature efficiently.
  • Opt for zone control to heat specific areas only when needed.
  • Regularly maintain the system to ensure optimal performance.
  • Choose energy-efficient floor coverings that allow heat to transfer effectively.
  • Avoid obstructing the heat flow with heavy furniture or rugs.
  • Consider installing thermal mass materials like screed for better heat retention.
  • Monitor and adjust the system settings according to seasonal changes in temperature.


Underfloor heating can be an extremely energy-efficient addition to your home, especially when you use it to replace an old traditional system such as a radiator. The wattage is much lower, and you end up saving on costs, especially when using a water system.

If you need help installing a water underfloor heating system, or want to know more about it's efficiency, Next Level is here to help. Contact one of our experts to get started with a free consultation and quote.

Extensive collage depicting the process of installing a water underfloor heating system.

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