UK should avoid rush to air-con as temperatures rise

Overheating is already a problem in UK homes, resulting in increasing levels of discomfort, illness and death.

In a new policy brief, University of Exeter researchers warn that – without intervention from policymakers – many more UK households will opt for air-con.

This would lead to more carbon emissions, create new challenges for the energy system, and increase inequality.

The researchers call for a “passive-first” approach to keep people cool, and make five key recommendations to reduce risks and support action.

“In temperate countries like the UK, buildings have largely been built to retain warmth in winter rather than keep out the heat,” said Richard Hoggett, from the University of Exeter.

“Already in an average summer, around 20% of homes in England experience overheating.

“Risks are currently higher in London and the South East, but all regions of the UK will need to adapt.

“Recent research on the 2022 heatwaves highlights that the country is currently ill-prepared for future extreme heat events.”

Dr Richard Lowes, of the University of Exeter and NGO the Regulatory Assistance Project, added: “Policymakers need a plan to keep the UK cool sustainably: supporting people to avoid unnecessary air conditioning, improving available products, and creating initiatives to help manage cooling loads within the energy system.

“The priority must be a passive-first approach, with information and support, alongside improvements to building regulations and planning – as existing homes are the main challenge.

“The UK has committed to producing a national cooling action plan by 2026, and we must now act quickly to deliver this and protect people from the many negative effects of overheating in homes.”

Passive cooling options include good insulation balanced with effective ventilation, and wider measures such as shading, reflective surfaces, cool roofs, and local “green and blue spaces” such as parks, trees and lakes.

The five key recommendations are:

• Act quickly and comprehensively: There is a “window of opportunity” to shape the future of cooling in UK homes, before overheating worsens and the domestic cooling market becomes established. Without action, air-con could become the new normal – creating unnecessary emissions and making it harder to decarbonise homes and the energy system. People should be supported to take a passive-first approach.
• Seek synergies: Reframing the challenge as “thermal comfort and health” would help break down existing policy silos and support higher visibility across government departments. “Quick wins” are available by integrating overheating and cooling into existing programmes that support decarbonisation in homes.
• Protect the most vulnerable and support all people: Vulnerable and disadvantaged are likely to be in poor housing, in areas that lack green space and suffer from higher pollution and overheating risks. An equitable approach to heat risk should be a policy priority.
• Build on, and share best practice: Examples of best practices in dealing with overheating and cooling in the UK should be bought together and shared to save time and resources. Many countries have been dealing with heat resilience for much longer than the UK – so there is an opportunity to learn from what works elsewhere.
• Lead nationally and support action locally: The UK needs an joined-up policy approach across heat resilience, cooling, health, climate and energy. Health and existing homes are the key challenge, but all departments and the devolved nations will need to play an active role. While national modelling helps identify which houses and areas may be most at risk, effective action is largely about the last mile of detail. Local authorities are therefore key to identifying risks and solutions.

The policy brief is entitled: “Decarbonising cooling in UK homes.”

It summarises work from the Flex-Cool-Store project – a collaborative research programme between Cardiff, Exeter and Bath universities, funded by the Engineering & Physical Sciences Research Council.