One in five homes in the UK are not equipped to deal with rising temperatures, according to researchers at Loughborough University.
They found around 20% of homes were already overheating and warned the problem would get worse as climate change continued.
Ben Roberts, an expert in indoor environments and building performance, said: “We’re looking at how we can adapt our homes to stay cooler in hot weather, without relying on air conditioning.
“UK homes are designed to keep heat in during winter – this also helps block heat from coming into the house through roofs and walls during summer too.
“However, it’s a problem when the sun’s heat enters through unshaded windows. Once the heat gets in, it gets trapped.”
Niloo Todeh Kharman, a PhD researcher, said: “Anyone who’s had a sleepless night in a hot bedroom knows how draining it is. Now imagine that every night for a week.
“Sleep deprivation increases your risk of illness, affects your ability to work, and can have longer-term consequences for things like heart health and even dementia.”
Roberts said many people were making homes hotter by opening windows during the day.
He said: “It might feel instinctive to let fresh air in – but if the air outside is hotter than inside, you’re just heating your house up.
“You’re better off keeping windows closed during the day, drawing light-coloured curtains or blinds on the sunny side, and only opening windows when it’s cooler in the evening.”
Roberts said night-time ventilation was one of the most effective ways to cool homes, but many people were worried about noise, air pollution or security.
He added: “It’s something we need to look at more seriously.
“We might need better window designs – things like secure grilles or automated systems – so people can cool their homes safely overnight.”
Industry partners like the British Blind and Shutter Association, Caribbean Blinds, Guthrie Douglas, Hunter Douglas, James Robertshaw, Serge Ferrari and Weinor are providing products for testing.
The aim is to find affordable, low-energy ways to keep homes cool.
Roberts gave his top tips for keeping homes cool: keep windows closed when it’s hotter outside than in, open windows at night when outdoor temperatures drop, use light-coloured curtains or reflective blinds on sunny windows, preferably on the outside, avoid dark-coloured curtains, and think about secure ways to ventilate at night, especially on ground floors.
Roberts said: “Ultimately, this is about future-proofing our homes.
“We need to start designing and managing our houses for a hotter climate. Not just for comfort, but for our health.”
The project is supported by the Chartered Institution of Building Services Engineers.
