The future of heat

The government has issued a call for evidence on a framework for heat in buildings. Hywel Davies looks at what it offers

In reviewing the Clean Growth Strategy, the Committee on Climate Change wanted more detail on several issues. As well as plans to phase out sales of petrol and diesel cars and vans by 2040, it focused on how we phase out the most polluting fossil-fuel heating in homes and businesses off the gas grid, and generate 85% of UK electricity from low-carbon sources by 2032.

The committee also wanted more detail on how we will increase energy efficiency in homes by 2035 – and for UK businesses and industry by 2030 – along with proposals to improve energy efficiency standards of new buildings.

When it comes to heat, the committee would like to see a clear, combined strategy for energy efficiency and low carbon. It also wants a significant increase in energy efficiency measures, as well as greater uptake of heat pumps and heat networks where appropriate.

In addition, it would like to see a proper evaluation of the potential for low carbon hydrogen to meet heat demand. The committee views low carbon heating and improved energy efficiency as ways to close the current shortfall in meeting the target of the fourth carbon budget.

On energy efficiency, there is scope to do much more. Some measures are obvious – and even free.

The recent cold snap in the UK highlighted the mindless policy of some UK retailers keeping shop doors open whatever the weather. They do this to attract potential customers, even if those customers are cold and ask to shut the doors – and regardless of the comfort of the shop staff.

If every retailer shut their doors, it would be a win for everyone: warmer customers and staff; reduced energy bills – which feed directly into increased profits (in a sector that faces huge pressure on margins and profits); and reduced UK emissions. And at zero cost, save that of the regulation!

No retailer will voluntarily go first, for fear of a drop in footfall, but if regulation required closed doors – as it does in New York – they would just do it. In the meantime, we forego emissions reductions and we all pay for wasted energy, as retailers defy the laws of thermodynamics and simple good engineering, and try to heat the world.

The government has already committed to reviewing Part L once the independent review of Building Regulations and fire safety is published, giving us the opportunity to propose further improvements to energy efficiency in our building stock. While we do not yet know the timescales, CIBSE members will be busy thinking about how we improve the efficiency of our homes and commercial buildings – as well as hospitals, schools and other public buildings – ready for the inevitable consultation.

We face radical reconfiguration of the energy system, and not just the energy supply system

Meanwhile, we must also think about how we heat buildings in future. The demise of internal combustion engines may be a way off, but switching to electric vehicles will have a profound effect on demand for, and distribution of, electricity, in the UK and all major economies.

With growth in distributed electricity generation from PV, wind and other renewables – and the move from fossil to electric heating – we face the most radical reconfiguration of the energy system in a century, and not just the energy supply system. It will have major implications for the systems we design and install in buildings.

Conventional fossil-fuel heating systems may no longer be the obvious choice for new buildings. As renewables deliver an increasing share of total capacity, assumptions about off-peak supply may need to change to match the improved output from PV systems in daylight hours. There is a lot of talk about battery storage, but what might that mean for individual buildings? How long will we continue to generate electricity through a PV array, transform it from DC to AC, move it a few metres, then transform it back to DC to power a handheld or mobile device? Why do we tolerate such inefficient processes? Perhaps we should revisit Edison’s DC supply system.

Against this backdrop, the government is calling for evidence about how we set about the long-term decarbonisation of heat. In particular, it wants information to support actions to move off-gas-grid buildings away from high-carbon fuels, but this is part of a much wider picture.

As an institution, we will be responding to this consultation and would welcome contributions from our members – and, indeed, other readers. While it is a UK exercise, it will be relevant to readers elsewhere, because many of the issues are not unique to this country.

Decarbonising the heating of our buildings poses questions about the way we design and service them. It will change the way we all work and the systems we design, install and manufacture, as well as the way we operate them. We have the chance to contribute to designing this change. Like closing the doors, we should just do it!

The consultation is available at

For more information on the CIBSE response to the consultation, visit

Dr HYWEL DAVIES is technical director at CIBSE