• New data finds that between 2019 and 2024, homes in England where households reported overheating increased from 1.7 million to 3 million
• Nesta has published a new deep dive into this data, highlighting that more needs to be done to ensure people are getting help adapting homes to extreme heat (and humidity) in the UK
• Air conditioning through air-to-air heat pumps can be a key part of the solution for helping people keep cool in summer and lowering carbon emissions from heating in winter, with £2,500 grants soon to be available and new government report indicating they have greater efficiency for heating than other systems

London, UK - The government has today released new data showing that the discomfort many people are experiencing during recent heatwaves in England is part of a pattern of overheating that is getting worse.

In particular, the new data finds that between 2019 and 2024, the proportion of occupied dwellings in England where households reported overheating increased from 7% to 12%, from 1.7 million to 3 million.

Despite this increase, many people were still having to resort to more traditional methods of cooling. The most common methods of keeping cool in 2024-25 were reported as opening the windows (89.7%), closing shutters/curtains/blinds (74.7%) or switching on a fan (58.7%).

Just 7.5% reported turning on air conditioning (AC). Of this group, owner occupiers (8.7%) were more likely to switch on an air conditioner to cool down than private renters (3.7%).

The research and innovation foundation Nesta is highlighting that more needs to be done to ensure people are getting help adapting homes to extreme heat (and humidity) in the UK - and that home decarbonisation can go hand in hand with making air conditioning a key pillar in helping people to cope with the heat.

Andrew Sissons, director of sustainable future at Nesta, said: “Anyone sweltering in this long-haul heatwave will recognise their own experiences in today’s figures showing that the number of people reporting overheating in their own homes has almost doubled in five years.

“As we experience hotter temperatures each summer, it is a real concern that for many people home is no respite. Overheating is not trivial - not only does it cause discomfort and reduces productivity, including for many people who work from home - but it is a big health risk, with rising excess deaths due to heat, particularly among older people.

“Somewhat surprisingly, air conditioning can be part of the solution not only for reducing overheating, but also for reducing carbon emissions from fossil fuel heating systems. Most air con units are air-to-air heat pumps, which can be used for much-needed cooling in summer and as a very efficient electric heat source to replace fossil fuel systems like gas boilers in winter. People will soon be able to get £2,500 towards replacing their boiler with these heating and cooling systems, but the government could make further tweaks to make this the easy choice for more people.”

Built-in air conditioning units are mostly a form of air-to-air (A2A) heat pumps, meaning they can work as a low-carbon heating system, while also adding air conditioning during the summer. England currently lags behind other countries when it comes to AC uptake, with under 5% of homes in England having AC, compared to 24% in France, 60% in China and 91% in Japan.

In April, it was announced that the government’s Boiler Upgrade Scheme (BUS) will offer £2,500 grants for certified installations of air-to-air heat pumps, alongside the £7,500 grants for other types of heat pump, such as air-to-water heat pumps that utilise a house’s radiators like a boiler. In addition, a new government report published today finds that A2A heat pumps, together with supplementary electric heaters (such as those used in bathrooms), provided space heating at a greater combined efficiency for three out of five home archetypes, when compared to other types of heating systems (including combi gas boilers).

Nesta is highlighting this summer as an opportunity for the UK government to consider expanding permitted development for two outdoor heat pump units to other (non-detached) property types. Similarly, the Leasehold and Freehold Reform Act 2024 could be changed to reduce the challenges associated with strict leaseholds installing these kinds of systems.

Ends

Notes to editors

1. Today (9 July), the Ministry for Housing, Communities and Local Government (MHCLG) published data from the English Housing Survey 2024 to 2025 weather resilient homes fact sheet: Annex tables and the Department for Energy Security and Net Zero published a new report, The suitability of reversible air-to-air heat pumps for UK domestic use.
2. Nesta has today published an examination of the new data, How well do homes in England cope with extreme weather? Five things we learned from fresh data.
3. According to the UK Health Security Agency, there were 1,311 heat-associated deaths during the 4 heat episodes in the summer of 2024 and there were 1,504 heat-associated deaths observed during 5 heat episodes in 2025. In 2025, significant heat-associated mortality is seen in those aged 85 years and over and those aged 75 to 84 years, with those aged 85 years and over having the highest number of heat-associated deaths.
4. For more information on the analysis or to speak to one of the experts involved, please contact Kieran Lowe, Media Manager, on 020 7438 2576 or [email protected]. Spokespeople are available for broadcast interviews.

About Nesta

Nesta is a research and innovation foundation that designs, tests and scales solutions for the biggest challenges of our time.

Driven by a vision to improve the lives of millions of people, our focus up to 2030 is on three missions: breaking the link between family background and life chances, halving obesity and cutting household carbon emissions.

We work with partners to develop high-potential solutions and test them as they evolve, drawing on expertise in qualitative and quantitative research, data science, behavioural science and design.

Once confident in the effectiveness of a solution, we take it to scale. We create national policy proposals, develop consumer-facing products and services, build and spin out commercial ventures and harness the power of the arts.

We work with two specialised units: BIT applies a deep understanding of human behaviour to help clients achieve their goals. Challenge Works designs and runs challenge prizes to spark innovation in science, technology and society. Find out more at nesta.org.uk