Retrofitting underfloor heating in an existing property



Underfloor heating is the perfect way to bring energy-efficient warmth to both new-build homes and existing properties.

As an increasingly popular method of primary heating – and a great alternative to radiators – many new-build properties now come with underfloor heating as standard.

However, when wanting to add underfloor heating to an older residential or commercial property, retrofitting is the only option.

As a leading supplier of wet and electric underfloor heating products, we’ve taken a look at the benefits of retrofitting underfloor heating and the key things you should consider before getting started.

What is retrofitting?

Retrofitting is a term used to describe a product, component or system being added after the initial manufacturing stage.

For underfloor heating, this means installing a new heating system into an existing property instead of incorporating it as part of a new-build project.

With the government’s 2050 Net Zero target firmly on everyone’s agenda, the concept of repurposing and retrofitting has become more popular due to its sustainability benefits.

As such, more and more businesses and homeowners are choosing to renovate their existing property rather than buying a new one – making retrofitting underfloor heating more popular than ever.

Choosing the right system

When it comes to choosing an underfloor heating system, there are two options: electric (dry) and wet (hydronic).

Electric underfloor heating is a highly efficient and effective way of heating an individual room or entire building. Quick and easy to install, heating cables or mats are laid underneath the floor to generate heat.

In addition to its speedy installation process, it also has little-to-no impact on floor height, meaning electric underfloor heating is well-suited to retrofit projects.

Plus, it can be paired with virtually any type of flooring including tile, stone, laminate and carpet, making it a great choice for a wide range of renovations.

Wet underfloor heating systems use pipes which circulate hot water to warm a room from the ground up. The pipes are installed within the flooring and connected to a central boiler or heat pump.

Where minimal floor build-up is required, low profile wet underfloor heating systems are the best choice for a retrofit project. As they can be used with heat pumps, wet systems are a great option for adding low-carbon heating to an existing property.

Another factor to consider when choosing an underfloor heating system is the budget available – both for installation and ongoing running costs.

Due to the speedy and straight-forward installation process, electric underfloor heating tends to be cheaper to fit but can work out more costly long-term.

The cost of fitting wet systems is often higher due to a more complex installation process. However, running costs are lower, making it a good investment choice for people planning to stay in their property for a long time or looking to add value prior to selling it.

Whilst weighing up the pros and cons of wet and electric systems is important, both offer many benefits and can significantly increase the value of a commercial or residential property.

What are the benefits of retrofitting underfloor heating?

From individual residential properties and housing developments to office blocks and large industrial units, underfloor heating offers long-term return on investment.

When compared with bulky radiators, floor space is maximised with underfloor heating – giving complete design freedom to individuals as well as businesses looking to enhance their living or working space.

Plus, underfloor heating adds a touch of luxury, significantly increasing the value of a property.

It’s therefore hardly surprising that underfloor heating is chosen not only by homeowners but by project managers, architects and developers too.

Things to consider when retrofitting underfloor heating

A number of things should be considered before and during the installation of underfloor heating, to ensure the system is fitted correctly and runs efficiently once it’s switched on.

Impact on floor height

One of the main challenges when adding underfloor heating to an existing property is the impact it has on the floor-to-ceiling height.

Unlike new-build projects, existing homes have fixed ceiling heights and door levels so you should select a system which won’t raise the floors too much.

To maintain the original floor height, retrofitting underfloor heating traditionally involved very intrusive works such as digging up existing floors prior to laying the pipework and re-screeding.

Nowadays, a wide range of low-profile underfloor heating options are available, causing less disruption and making installation much quicker and simpler.

The type of floor and sub-floor

When fitting a new heating system, the existing flooring should be removed and replaced with a new floor covering. This is because it may be difficult to lay the same flooring back down again without causing significant damage.

The sub-floor should be cleaned and insulation added before installing underfloor heating and laying down the new floor covering. This will ensure the floor is appropriately prepared before the heating system is switched on.

When using tile or stone floors, it’s also important to ensure the floor is sturdy and free from flexing. Additional strengthening with plywood or other appropriate materials may be required.

The building’s insulation

One of the key considerations prior to installing underfloor heating is the thermal efficiency of the building.

If a house is poorly insulated – for example with single glazed windows – the thermal fabric will likely require upgrading to ensure underfloor heating can run efficiently.

Also, poorly insulated or draughty properties need more heat and therefore a larger underfloor heating system. This not only increases installation cost but also running costs – meaning it’s a less viable heating option.