For years, heat pumps have been presented as the answer to home heating decarbonisation rather than a part of the solution alongside other technologies. Ministers regularly point to rising installation numbers as evidence that the transition is gathering pace. Because it is net zero, questions are rarely asked about the cost.

The latest data from DESNZ is revealing. In 2025/26, almost 50,000 air source heat pumps were retrofitted into existing UK homes. On the face of it, that sounds impressive. Yet a closer examination reveals that over 90 per cent of those installations were supported by public subsidy schemes such as the Boiler Upgrade Scheme (BUS), Energy Company Obligation (ECO), Social Housing Decarbonisation Fund (SHDF) and Home Upgrade Grant (HUG). In total, 45,397 of the 49,880 retrofit installations relied on some form of taxpayer or bill payer support.

The scale of that support is significant. Every heat pump already benefits from zero-rated VAT, costing the Exchequer an estimated £1,000 per installation. On top of that sit direct grants and subsidies, which range from £7,500 under BUS to fully funded installations worth considerably more under other government-backed schemes. Combined, these subsidies and bill payer-funded contributions amounted to almost £499 million in 2025/26 alone.

What did that investment buy?

Using official carbon intensity factors and Ofgem's typical domestic energy consumption figures, each heat pump is estimated to save around 1.5 tonnes of carbon dioxide per year when replacing a gas boiler. Across the entire retrofit market, that equates to annual savings of roughly 76,000 tonnes of CO₂e. Over an assumed 15-year lifespan, the total lifetime saving is just over 1.14 million tonnes.

The result is striking: the public cost of delivering those carbon reductions is approximately £437 for every tonne of carbon saved.

This matters because it places heat pump retrofits above the Government's own valuation of carbon and towards the expensive end of the decarbonisation league table.

If net zero is to retain public support, policymakers must focus not simply on carbon savings, but on achieving them at a cost consumers and taxpayers can reasonably afford. Perhaps it is not just footie fans that need to have this printed in a very large font.