British houses were built to conserve heat. It becomes a problem.

For generations homes in Britain have been designed to retain heat, to make cold winters bearable.

Keeping them cool in the mild summers was an afterthought, if it was an afterthought at all.

But in recent years, each new heat wave brings a new reminder that buying a fan or two just won't always cut it. Builders and designers are increasingly interested, with the help of activists and the government, in having new homes built to limit overheating in the summer.

New regulations, called Part O, came into force in England in June, requiring new homes to be built with certain measures to combat overheating. The regulations aim to reduce solar gain – the increase in ambient temperature caused by sunlight – ensuring occupants are safe, although it may still be uncomfortable.

The rules "will help designers, architects and engineers make more informed decisions so that the risk of overheating can be reduced in new properties," said Mark Siddall, Director of Low Energy Architectural Practice. Often, he says, rooms gain a lot of heat through large windows facing in certain directions - the kind of design decision that future homes might consider more fully.

Historically, designers in Britain haven't worried too much about overheating, said Susie Diamond, founder of Inkling LLP.

"We didn't need to be protected from the heat waves, it wasn't a priority,” she said.

But with the climate change that makes heat waves more frequent and summers get hotter, that's no longer the case.Ms Diamond said good design that accounts for overheating - including windows that open open wider and the addition of ceiling fans - can solve many problems without using air conditioning which is rare in Britain and often considered harmful to the environment and unnecessary for all but a few days a year.

Over the past decade, the Climate Change Committee, a group independent which advises the British government, called for stricter building regulations to combat overheating, while with a renovation program for older homes. A June 2021 report called for better shading, reflective surfaces and green roofing, warning that a failure to build new homes without considering overheating could "leave many existing and new homes uninhabitable as temperatures rise. increase".