Underfloor Heating: An Introduction

In many cases, especially through the long, dark winter months, it is impossible to achieve true comfort without first achieving warmth.

In fact, being warm is often something that is taken for granted – however, even with the best insulation installed, temperatures may be so low as to need help in the form of additional heating.

Obviously, there are several ways to heat your home but by far, the most comfortable is by radiant heat. This is heat that emanates from a hot source, similar to the gentle warmth of the sun.

By projecting this radiant heat through the floor, you can produce a perfect warmth which surrounds you and creates the ultimately comfortable atmosphere.

The Romans first developed underfloor heating over 2,000 years ago by using a furnace to heat the air in underground spaces, such as cellars. This air would then circulate and travel up channels in the walls to warm the rooms above.

Why is Underfloor Heating so Special?

Conventional heating systems work by heating the air next to them (e.g. radiators) and relying on the air convection to transfer the heat around the room.

This tends to produce a situation where hot air rises to the ceiling, either escaping through the roof, or cooling and returning back down to ground level.

This leads to a vicious circle where your head is overheated, leading to stuffiness, and your feet remain cold.

As warm feet are the body’s natural thermostat for comfort, increased heating to achieve warm feet simply means more discomfort for an already over-heated head.

Underfloor heating works differently by generating 50% of its warmth via low-temperature radiant heat which does not rely on air convection.

It is simply released evenly and absorbed by the people and objects in the room. It also reverses the temperature profile by gently heating the room from bottom up, so that the ground level is warmest.

This creates the ideal situation where there the body feels comfortable with warm feet and cool head. It also means that heat loss is reduced from people’s bodies without overheating the ambient air.

Electric Underfloor Heating

Electric Underfloor Heating is the way underflooring heating was first developed, using electric resistance cables laid into thick concrete subfloors which were then heated during the night using cheaper electricity.

However, there were some problems due to poor temperature control and floors were often too hot in the morning.

Modern versions are more sophisticated. They can come either as a loose wire system with a dual-core heating element which can be installed without digging up the floor or embedding anything in concrete.

In fact, the system is simply fixed to the subfloor and the chosen flooring material (e.g. tile) laid back over it.

Alternatively, you can use matting system where the electrical heating element is attached to a tough fibreglass mesh which is then rolled out to cover the subfloor, before installing the final flooring material.

Both methods have been shown to be economical and environmentally-friendly.

Warm Water Underfloor Heating

A newer method of underfloor heating is to use Warm Water circulated from the boiler through continuous lengths of pipe embedded under the floors.

This uses a similar heating process as radiators and is electrically operated so as to provide room-by-room temperature control. It is particularly useful for specific zones and extensions, such as conservatories, which may need to be heated at different times to the rest of the house and may suffer from extensive heat loss.

It is claimed that warm water systems are more economical than electric underfloor heating.

What about Efficiency?

One of the reasons people have shied away from underfloor heating in the past is worries about efficiency and the system’s energy-saving abilities.

Some studies have been done and the results show that energy consumption by underfloor heaters range from 10% more than conventional heating systems to about 50% less than conventional heating systems.

This variation is due to the type of insulation in place, the usage patterns of the occupants and the personal preferences for ambient temperature.

Generally, radiant heating systems are considered very efficient as it creates an atmosphere with a lower ambient temperature due to less heat loss from your body.

However, if you insist on achieving the same ambient temperature as with conventional heating, you could end up overheating the room and thus losing out on energy savings.


If all the occupants are out at work during the day but then have a different routine at weekends, a good thing to install would be a thermostat connected to your underfloor heating system so that you can programme a schedule to suit your lifestyle.

See Also
Electric floor heating control
Underfloor Heating: Electrical
Boy playing on floor
Underfloor Insulation