This summer, temperatures in England breached the 40ºC mark for the first time at a place called Coningsby in Lincolnshire. Records were also broken in Scotland, with temperatures reaching 34.8ºC in the Scottish Borders and temperatures reaching 37.1ºC in Wales. While most of the country baked under a relentless sun, an area of Europe equivalent to a fifth of Belgium was devastated by wildfires after months of high temperatures and no rain.

Scientists are warning that it will get worse. If we do not reduce carbon emissions, the Met Office predicts that 40ºC summers could occur every three years by the end of this century. A summer as warm as 2018, the hottest on record, would have been less than 10% likely to occur between 1981 and 2000 but is now expected every other year by 2050.

Heatwaves will become hotter and more prolonged, with consequential impacts on health and productivity. There is plenty of evidence that many UK buildings regularly overheat in the summer, and a new building regulation, Part O, was introduced in June to try to mitigate that problem in new homes. But what about offices, schools and hospitals, and what about existing buildings? Below, we examine how extensive the overheating problem is, whether Part O will help, and what can be done about mitigating overheating in buildings that already exist.

…