Floor Heating for Retrofitting

There are lots of benefits to installing an underfloor heating or cooling system, so it’s not surprising that it’s becoming a popular choice for retrofit projects to existing properties. These include extensions, partial or complete renovations and other projects such as barn conversions.

These days, there’s a good choice of underfloor heating systems suitable for retrofit projects and the installation process is somewhat easier than it used to be. Having said that, retrofits are still the most complex type of underfloor heating project and there are quite a few things to consider.

We’ve put together some of the most common questions we’re asked about retrofitting underfloor heating, to help you decide if it’s the best choice for your project and if so, to get you started.

We supply and fit

This depends on the type of project. If you’re renovating a property, it’s likely to have lower levels of insulation than current regulations require. You’ll need to compare the heat output of your chosen underfloor heating system with the rate the building loses heat. Radiant Heating Solutions can help you with this and recommend a system that gives the performance level you’re looking for.

On the other hand, if you’re building an extension or refurbishing a property to current Building Regulations standards, you’ll probably have more options. Have a look at the different system types to see how easy they are to install. You could consider a simple set-up with boards that go over the existing floor, perhaps using pre-routed boards to save you time.

Be warned, however, that this kind of installation can increase floor height, so always check the total height of the system. You’ll find more information about this on our Can I Fit It? page.

Yes, underfloor heating with work with any type of boiler or central heating, including renewable energy options such as an air or ground source heat pump or wood-burning or biomass boiler. If you’re just installing underfloor heating in part of your house, it will run alongside the conventional heating system used in the other rooms.

This depends on the size of the project, for example, whether you’re fitting underfloor heating to a single room or throughout the property. In general, however, retrofit systems are quick and simple to install. One of our Registered Installers recently installed a 40m2 system in under 4 hours and had the floor coverings down just 3 days later. In many cases these retrofit systems can be a cheaper option than digging up your floors!

Do bear in mind, however, that if you’re fitting a new wooden floor, the planks will need at least 10 days to acclimatise before being laid – see our Floor Coverings page for details.

Pre-routed gypsum boards or polystyrene panels with metal heat diffuser plates are the most common types of retrofit system on the market. As dry systems, they’re easy to work with and have very little impact on building schedules.

Not usually. Most retrofit systems are designed to be laid over the existing floor deck without the need for excavation. This may increase floor height, however, as noted above.

Yes! The heat output required will depend on the building’s fabric and insulation levels, so some projects will need less output than others. If this is the case, you could combine your underfloor heating with an air or ground source heat pump, as these can operate efficiently at lower temperatures, further reducing your energy use and bills.

Unfortunately, your options will be more limited if the building has low insulation levels. You might need to opt for a system with a higher output of 120W/m², rather than the standard 80W/m². This will almost certainly need to be paired with a gas or oil-fired boiler, although modern types are highly energy efficient.

Variotherm is a product that offers a fast and effective retrofit solution. It’s a strong board where pipes are installed and covered over with a slurry product. Timber, laminate, and tiles can be laid directly onto the boards, so there’s no need for screed etc to be added. Carpets can also be laid onto Variotherm, although a self-levelling compound would need to be installed first.

Possibly, but you’ll need to make sure your chosen system can meet the building’s heating requirements. Because underfloor heating operates at lower temperatures than conventional systems, you’ll need to assess the levels of insulation and heat loss carefully.

Having said that, you could always install an extra heat source such as a log burner for occasional use, or in the odd room with very high heat loss, to supplement your underfloor heating. You could also look at improving current insulation levels if you can do this without too much disruption.

The most important thing to consider is that your underfloor heating can perform as expected. If this simply isn’t possibly, you’d be better off sticking with a traditional system.

Your system can provide both, providing it’s connected to a heat pump with a cooling function. The only variation is the room thermostat which has to be a heating and cooling device. For alternatives to an underfloor system, please visit our Variotherm Wall & Ceiling Heating and Cooling.

Of course! We can help with individual aspects of the project or take care of everything from start to finish. Our experienced team can design, supply and install an underfloor heating system that meets your precise needs and keeps you warm and cosy for years to come.

If you want to add an air or ground source heat pump to run alongside your underfloor heating, we can design a ‘whole house heating system’ for you. This will make sure the heat pump, underfloor heating and hot water system all perform to your requirements, whilst supplying you with the best possible energy efficiencies at the same time.