More than a third of Britons say their homes are not suitable for today’s climate, a report has found.

The findings come after a summer of record-breaking temperatures, with Kew Gardens reaching 38.1°C and temperatures exceeding 30°C on 40 days across the UK — surpassing the previous record of 34 days set in 1995.

The new Heat-Trap Homes Report from trade website MyBuilder found that 37% of people said heat in their homes had negatively affected their wellbeing, while almost half (46%) experienced poor sleep because of high temperatures.

For one in five respondents, the heat became so intense that their bedroom was unusable during heatwaves, while 5% said they resorted to sleeping outside to escape the temperature indoors.

The heat also affected people’s ability to work, with 18% of those working from home saying they struggled to concentrate or remain productive.

Andy Simms, home and construction expert at MyBuilder, said the summer had highlighted a growing problem with Britain’s housing stock.

“The UK’s hottest summer on record exposed a major problem: Britain’s housing stock was not built for this,” he said.

“Most of our homes are designed to hold heat in, not let it out, and this summer showed just how big a problem that’s becoming.”

The research suggests attitudes towards keeping homes cool are changing, with 39% of people now viewing air conditioning as a necessity rather than a luxury.

Demand appears to be following the shift in attitudes. MyBuilder.com’s platform data shows searches for home air conditioning increased by 150% year-on-year, as households looked for ways to cope with rising temperatures.

However, the cost of adapting homes remains a significant obstacle.

More than a third of those surveyed (37%) said they could not afford the changes they would like to make to their homes to cope with extreme heat. Among people with children living in their homes, that figure rose to 51%.

There is also uncertainty about which technologies and financial support are available.

Almost half of respondents (49%) said they were unaware that some heat pump systems can provide cooling as well as heating, while 56% said they did not know which grants or subsidies were available for sustainable home improvements.

Simms said solutions were already available but argued that affordability and a lack of information were preventing households from making changes.

“Solutions already exist, but affordability concerns and confusion about available options are blocking change,” he said.

“Closing that gap has to be the priority as we face increasingly hotter summers.”

The research was conducted by Opinium on behalf of MyBuilder among a nationally representative sample of 2,000 UK adults aged 18 and over, between 3 and 8 September 2026.

Of those surveyed, 1,380 were homeowners. Statistics specifically referring to homeowners are based on this subset of respondents.

In June, major insurer Zurich found that more than 100,000 homes could become “uninhabitable” in high temperatures as the boom in office-to-residential conversions has created heat-trap flats.