Roadmap to decarbonised heating: are we on track?

Chris Caton, Product Director – Commercial, at Ideal Heating

Scientific consensus is that the world must reach net zero by 2050 to prevent the worst effects of climate change.  A key step towards net zero in the UK is reducing greenhouse gas emissions (GHG).  In the UK, the building sector is the second largest emitter of GHGs, with most of these emissions resulting from heating and hot water demand in homes being fulfilled by natural gas.  In total, the heating of homes and workspaces makes up almost a third of UK carbon emissions.

Decarbonising heating in our buildings, primarily through the replacement of natural gas boilers with heat pumps, is therefore a key government goal.  But with any change comes uncertainty and let’s not underplay the extent of this change: almost 80% of homes in the UK are currently heated by natural gas and a quick scan of any news source or social media platform shows resistance to heat pumps is high.  Every time the government makes an announcement about heat pumps, uncertainty and confusion abound.

The latest major government announcement (I think it’s important I state that this is at the time of writing!) was in September 2023 when the Prime Minister advised of delays to some climate targets – including the phase out of off-grid gas boilers – in a bid to save people money during the cost of living crisis.  For many, this has been viewed as a watering-down of the UK’s net zero policies.

But what impact will this, and more recent developments, actually have on the decarbonisation of heating in buildings?

What’s actually changed?

The headline news is that a 20% exemption to the phase-out of all fossil fuel boilers has been provided, and the phasing out of fossil fuel heating installations for off the gas grid properties in England, set in the government’s Heat and Buildings Strategy for 2026, has been pushed back to 2035.  Furthermore, it will include an exemption for off-gas grid properties where there is no suitable low carbon heating solution.  A consultation will be held shortly to explore the potential low carbon heating options for off-gas grid properties that are not suitable for heat pumps.  This essentially means an 80% phase-out by 2035, rather than 100%.

All other Government policies on heating remain the same as before, with the target of deploying 600,000 heat pumps per year by 2028 unchanged. The Future Homes Standard and the Future Building Standard will still be introduced in 2025 in England to ensure new buildings are built to be as efficient as possible. The Heat Pump Investment Accelerator Competition and the Heat Training Grant will continue unchanged, and the Heat Network Market Framework and Heat Network Zoning will also continue as planned.

Under the Boiler Upgrade Scheme, available in England and Wales, the grant level has doubled for heat pumps to £7,500. Biomass boilers will continue to receive grants of £5,000.  Phase 4 of the Public Sector Decarbonisation scheme will see £1.17bn worth of grants for 2025/2026 – 2027/2028, to enable public sector organisations to switch to clean energy as well as installing energy efficiency measures.  There remains no funding for private sector non-domestic properties. 

Why heat pumps for net zero?

Heat pumps are up to a third more efficient than gas boilers, with potential for even further efficiency as the technology develops. Of course, this level of efficiency does rely on the key success factors of system design and the overall thermal efficiency of the building. A heat pump system that is not correctly sized, or a building without effective insulation, will require more energy to keep at the desired temperature, meaning the heat pump is then not operating at maximum efficiency.

What next?

There can be no doubt that heat pumps will be the core means of decarbonising heating in buildings.  However, whether the target of deploying 600,000 heat pumps per year by 2028 can be achieved remains hotly debated. The UK had the lowest number of heat pumps installed per capita in 2022 compared to neighbouring countries.

There are a number of factors at play here, including the cost of heat pumps (plus comparatively high running costs), lack of public trust in them, and the scarcity of trained installers.  When it comes to the latter, training really is essential as, whilst there are some similarities, fitting a heat pump is quite distinct from a gas boiler.  

It’s clear that there are challenges here, but also plenty of opportunities. There isn’t a one-stop, overnight solution to get to net zero and decarbonise UK heating; this is going to be a stepped process, but it is one we must make.