In October, the UK chancellor Rishi Sunak announced a £450m package to install heat pumps around the country. This would provide around 90,000 homeowners a £5,000 grant to replace their gas boilers with electric heat pumps. While such announcements are in step in the right direction in terms of carbon reduction, the UK will need to do a lot more to meet its target of 600,000 heat pump installations by 2028. Homeowners will be unimpressed with heats pumps without a more holistic heating strategy. Instead, the government should listen to a rather unpopular group.

The protest group Insulate Britain has garnered some unsavoury headlines in 2021. Blocking roads by means of sticking themselves, sometimes with glue, to the asphalt has infuriated motorists and done little to improve public opinion around their cause. Indeed, a YouGov poll in September found that 64% of the general UK population believe that such action hinders their cause.

However, Insulate Britain makes an important point. The group calls on the government to retrofit the insulation of UK social housing by 2025, and all UK homes by 2030. UK housing stock is notoriously drafty and poorly insulated, which is exactly why insulation funding should come hand-in-hand with heat pump installations. With 14% of the UK’s carbon emissions coming from home energy use, this is a critical issue.

Heat pumps are in essence a refrigerator in reverse. They use heat from outside (even during cold weather) to force special gases to contract, heating the gas, which can then be used to provide heat elsewhere. Since only electricity is used to power the process, heat pump operation is carbon-free, provided the electricity was generated without fossil fuels. Great. So why aren’t heat pumps a climate change panacea?

They are simply much less efficient than gas heating. Since heat pumps output a lower temperature to radiators than gas boilers, poorly-insulated homes lose significant amounts of heat while using heat pumps. This had led to many being disappointed with their choice of a heat pump, as they simply don’t heat houses well enough that don’t have proper insulation. Also, they can be expensive. Housing expert Rogert Bisby estimates that most installations of heat pumps end up costing three times more than gas boilers.

Heat pumps have worked well in places such as Scandinavia, where most houses are well-insulated. Cavity wall insulation, triple glazing, and underfloor heating are common. These are much more suitable conditions for heat pumps, as compared to the UK’s old housing stock, where solid walls and sash windows are often the norm. These leak heat to the environment and make heat pumps perform poorly.

So what should the government do? Insulate Britain. Heat pumps will not work unless the country is well-insulated. Retrofitting the entirety of the UK’s housing stock is no doubt a monumental task. But, if the government wants to be serious about reducing housing-related carbon emissions, it is a task that needs to be done.