Everything you need to know about retrofitting underfloor heating in loft conversions

In recent years, loft conversions have become a popular home renovation project across the UK, giving homeowners a cost-effective way to make the most of their space and add value to their property.

While some may believe that underfloor heating isn’t suitable for loft conversions, retrofit electric underfloor heating is actually an ideal solution for a loft conversion project!

At Amber Underfloor Heating, we have over 35 years of experience providing efficient underfloor heating systems to the trade through our network of stockists – for both new-build and retrofit projects.

In this blog, we’ll explore everything you need to know about retrofitting underfloor heating in loft spaces – including things to consider before installation and the benefits of underfloor heating systems.

Things to consider when installing underfloor heating in loft conversions

1. Choosing the most suitable system

There are two main types of underfloor heating systems available on the market – wet and electric underfloor heating.

Whilst both electric and wet underfloor heating can be used for loft conversion projects, electric systems are much more suitable for retrofitting.

Electric underfloor heating

Electric underfloor heating systems consist of electric heating mats or loose cables (fitted with decoupling membrane) which are installed beneath the floor covering to provide consistent warmth.

Loft conversions are typically smaller spaces, which electric underfloor heating systems are ideal for due to their ease and speed of installation. Plus, electric systems are particularly suited for spaces where height restrictions are a concern, as they require less floor build-up than wet systems.

Wet underfloor heating

Wet underfloor heating systems involve flexible water-filled pipes which are installed underneath the floor and connected to a heating source, like a heat pump or boiler. Warm water circulates through the pipes to heat the floor.

While it can be suitable for loft projects, retrofitting wet underfloor heating into a loft conversion is rare as it requires raised floor height due to the screed and pipes involved, and can cause issues with floor weight.

Here at Amber, we advise retrofitting electric underfloor heating in loft conversion projects. The choice between electric mats or individual heating cables and decoupling membrane will depend on factors such as space, obstacles insulation and budget.

2. Heat loss

Loft spaces are prone to heat loss as heat naturally rises and can escape through the roof.

So, if a loft space is not adequately insulated, underfloor heating won’t run efficiently, leading to higher energy costs. Therefore, it’s essential to have proper insulation to prevent heat from escaping through the walls and roof.

To ensure the best results from underfloor heating in a loft conversion, it’s advisable to carry out a heat loss calculation prior to installation.

This assessment will help to determine the right type of insulation needed and the power output required for the underfloor heating system to heat the space effectively.

We advise installing electric underfloor heating systems on top of insulation boards to help reduce heat loss.

3. Floor height and build-up

Another important consideration is the floor height added by the underfloor heating system itself.

Loft conversions often have limited space as it is, so increased floor height could be a concern when installing underfloor heating, especially in a loft with a low ceiling.

Although minimal, electric underfloor heating will increase the floor height by a small amount. For this reason, many people opt for low-profile electric systems, like thin electric heating mats, to minimise floor build-up.

Careful planning is crucial to avoid losing too much headroom in the finished space.

4. Flooring compatibility

The type of flooring for a loft conversion project will impact the performance of the underfloor heating system, so choosing the most suitable option is key.

Underfloor heating works best with materials that have good thermal conductivity, such as tile, stone or engineered wood. These materials allow heat to transfer quickly and evenly throughout the room.

However, carpet is a popular choice for loft conversions, especially as many are used as bedrooms. Contrary to what some may think, underfloor heating is compatible with carpet.

Low tog carpets are ideal, as carpets which are too thick will heavily insulate the floor and minimise the amount of heat which comes through. The combined tog rating of the carpet and underlay should therefore not exceed 2.5 tog.

For more information on flooring compatibility, read our guide on which flooring is suitable for underfloor heating.

What are the main benefits of retrofitting underfloor heating in loft conversions?

Easy to install

Electric underfloor heating is a simple retrofit solution due to its easy installation process.

Electric heating mats can simply be rolled out and secured for simple installation.

Loose-lay heating cables can be installed and secured on their own, or paired with a decoupling membrane which securely embeds the cables into its studs to hold them in place.

Here at Amber, we advise installing electric underfloor heating on insulation boards, followed by self-levelling compound and then the floor covering.

Energy efficiency

Underfloor heating is highly efficient.

It’s up to 30% more efficient than traditional radiator and boiler systems because, while radiators require temperatures of around 70°C, underfloor heating operates at a much lower temperature of about 35°C.

This means underfloor heating can reach the desired warmth faster, using less energy to do so.

Cost effectiveness

Due to its energy efficiency, underfloor heating is typically a cost-effective option for loft conversions.

As it distributes heat more evenly compared to traditional radiators – and runs at a lower temperature – energy consumption is reduced, which helps to bring energy bills down.

Plus, programmable thermostats and zoning options allow for precise control, helping to further optimise energy consumption and reduce costs.

Design freedom

One of the biggest advantages of underfloor heating is the design flexibility it offers.

Without the need for bulky radiators, underfloor heating provides complete freedom to arrange furniture and décor, making the most of every inch of new loft space.

Whatever the project, underfloor heating delivers a clean, minimalist look while providing consistent warmth.

Reliable and energy-efficient underfloor heating from Amber

By retrofitting electric underfloor heating into a loft project, you can create a comfortable, energy-efficient environment for your customer that fits seamlessly into their space’s existing design.

Here at Amber, we supply a wide range of underfloor heating products, so you can find the perfect solution for any loft conversion project.

We have a comprehensive network of stockists across the UK and Ireland who supply our products for tradespeople. This means that you’re never too far from an Amber stockist!

We also offer all customers a free design service, site visits and access to our technical team if needed. So, whether you’re a tradesperson, M&E contractor, specifier or architect, our friendly team are on hand to help with your next project.

Contact us today to learn more.