The Electrification of Heat project, led by Energy Systems Catapult with government funding, installed more than 700 heat pumps across Great Britain to test how they perform in real homes.

The installations covered a broad range of housing types – from Victorian terraces and pre-war semis to 1960s flats and modern homes – reflecting the diversity of the UK’s housing stock.

The project found no property type or architectural era that was inherently unsuitable for a heat pump. While older and hard-to-treat homes required more careful design, insulation, and planning, these challenges were successfully overcome. In total, 163 installations were completed in homes built before 1945, demonstrating that even historic properties can switch to low-carbon heating with the right approach.

The project used a mix of air-source, ground-source, and hybrid systems to test performance across different settings. It also explored how careful system design – from emitter sizing to heat-loss calculations – makes the biggest difference to comfort and efficiency.

The findings challenge the common perception that heat pumps only suit new-build or well-insulated properties. Instead, they show that with proper planning and skilled installation, heat pumps can provide an effective, low-carbon alternative to gas heating for almost any home.

“This trial demonstrates that low-carbon heating systems are an effective alternative for homes of all types and ages. As technology continues to improve and costs plummet over the next decade, they will become the obvious, affordable choice for consumers.”

Lord Callanan, Energy and Clean Growth Minister

As technology continues to improve and more households move away from fossil fuels, heat pumps are becoming an increasingly practical option for homeowners looking to cut carbon and make their homes more comfortable.