Biggest ever test of heating in homes as UK prepares to go gas-free

As the UK prepares to go gas-free under new Government rules to reduce the carbon footprint of homes, researchers at the unique Energy House 2.0 research facility at the University of Salford, working with housebuilders Bellway and Barratt Redrow and construction solutions manufacturer Saint-Gobain UK and Ireland, have spent the past 12 months testing 14 different heating systems to see which ones will heat consumers’ homes the best at the lowest cost.

The findings will help new buyers, existing homeowners, renters and landlords to understand the most efficient ways to heat homes when gas boilers begin to be phased out in new homes from 2025. Existing homes have until 2035 to replace gas boilers.

Energy House 2.0 is a specially built climate chamber that recreates temperatures ranging from -20˚C to +40˚C, as well as simulating wind, rain, snow and solar radiation. The chamber enables Barratt Redrow, Saint-Gobain and Bellway to test methods of construction and products at temperatures that would represent anything from a Nordic winter to an African summer. The Energy House 2,0 chamber can simulate the weather conditions in 95% of the world’s current climates, as well as the climates predicted in the future.

Richard Fitton, Professor of Building Performance at the University of Salford said: “Without the unique facilities we have here at Salford, it would take years to deliver these results that we have achieved in just a few months of testing on each home.

“Energy House 2.0 allows for a comparison between heating technologies at constant extreme temperatures, which up to this moment has not been possible and our results represent unique research. These insights will be invaluable as we try to reduce the carbon emitted in heating our homes, whilst ensuring people are warm and comfortable in their homes without paying too much on their bills.”

The systems tested at Energy House 2.0 covered a range of technologies including Infrared heat panels, air source heat pumps, underfloor heating, skirting board heating and traditional radiators.

The research looked at two different heating patterns – 24-hour constant heating and a pattern of a house being heated between the hours of 07:00-09:00 in the morning and 16:00-23:00 at night, that is currently used in the standard energy model (SAP), and is the typical way that people live in their homes in the UK.

Tests were conducted at both a typical winter temperature of 5 °C and also, an extreme winter temperature of -5 °C within the climate chamber.

The key findings from the research are:

•    Air Source Heat Pumps can cost as little as £1.84 on a typical winter day to heat a home and are more efficient than current gas boilers.
•    The most common method of heating homes in the UK is currently gas boilers, which are designed to reach temperatures of up to 70 °C quickly and be used for short periods of time that fit around the typical consumers’ lifestyle (morning and evening heating). During the extreme winter condition test the electrified heating systems did not perform well when used in the typical way that consumers with gas boilers would use heating. Consumers with the new heating systems would need to adjust to using them in a more constant way to get the best heat at the most efficient cost. 

Bellway’s house, named The Future Home, tested two air source heat pumps, including the UK’s first roof-mounted prototype, along with underfloor, infrared and ambient heating, and mechanical heat recovery ventilation.

Bellway’s home demonstrated that underfloor heating and air source heat pumps work well together, while Infrared heating could be used more widely in flats and maisonettes, where ASHPs are difficult to install. The research project complements Bellway’s pilot projects around the country, with 11 exemplar homes already completed. Bellway installed 163 ASHPs in homes during 2024 and has plans for a further 1,400.

Saint-Gobain partnered with Barratt Redrow in constructing eHome2 which looked at how to deliver zero carbon housing at scale using off-site lightweight construction solutions. eHome2 piloted the use of next generation heating and ventilation technologies as well as smart technology  

The eHome2 has a host of innovative solutions from Saint-Gobain including its weberwall brick, a high-performing timber frame system from its Scotframe brand and its Pasquill Posi-JoistTM floor cassettes that allow for the integration of Mechanical Ventilation & Heat Recovery systems (MVHR).

Oliver Novakovic, Director of Technical & Innovation at Barratt Redrow, said: “The Energy House 2.0 research is one of the most important R&D projects that Barratt Redrow has ever undertaken. It will inform us about the homes that we build in the next 20, 50 and 100 years. We will see more extreme weather events and we need to ensure that the fabric of the homes we build, and the heating and cooling emitters that we fit, provide the most temperature efficient and cost effective outputs for residents.”

Jamie Bursnell, Head of Technical and Innovation for Bellway, said: “The heating tests at Energy House 2.0 have accelerated our understanding of how new homes can be heated through electric sources. The comparison of different combinations of heating technologies working in a controlled environment has highlighted some highly efficient systems. We will now refine and test further, and the research will inform our work with new technologies on the live developments where these are already being trialled.”

Mike Chaldecott, Saint-Gobain UK’s CEO said: “This research comes at a critical time. Never before have real homes been tested under such precise conditions to help inform us about how to build homes that will perform in the climates we face today and a generation and beyond from now. The way we build is undergoing rapid change – from heavy, carbon intensive materials, to lighter, more sustainable building solutions, with large parts of buildings built in factories and assembled on site. This research is critical to understanding how we can do that at the scale we need in the future, cost-effectively, with greater levels of productivity while being sure of how those new building solutions perform in a changing climate.”

Professor Will Swan, Director of Energy House Labs at the University of Salford, said said: “The innovation accelerator has been a great opportunity for academia and industry to work together on the UK priorities of Net Zero and energy efficiency

“The heating system report is a collaborative effort between Energy House and our partners to understand what electrification might look like in our future homes.”