Brits urged to close windows during heatwave

With temperatures soaring beyond 30C this week, millions of Brits have been bearing with stifling rooms and restless nights. In a country where homes are built to trap heat rather than release it, many are reaching for fans or flinging windows wide open in the hope of relief. But experts warn that opening your windows at the wrong time could be making the problem worse.

Alan Reid, a double-glazed doors and windows expert at Art Windows and Doors, says the golden rule in a heatwave is simple: keep your windows shut when it is hotter outside than in. “Opening your windows is not cooling your home, it is just letting more heat come flooding in,” he said.

Instead, Reid recommends waiting until the evening and early morning when the air outside is noticeably cooler before opening windows.

This allows trapped heat to escape without introducing more warmth. For those worried about leaving windows open overnight because of security, noise or insects, Reid suggests using a night vent setting.

“Most modern windows have a built-in vent lock or night catch which lets you crack the window slightly for airflow without leaving it fully open,” he said.

“Used at the right time when the outdoor air is cooler, it can help release heat from your home and make it more comfortable.”

To keep your home cooler this week, experts advise closing all windows and blinds during the hottest hours of the day, particularly on south-facing sides.

Once the sun begins to set and the air cools, typically after 8pm, open windows wide or use the night vent setting to allow a gentle, sustained flow of fresh air. Repeat the process in the early morning before temperatures rise again.

Creating cross-ventilation by opening windows on opposite sides of your home can help draw in fresh air and push out hot, stale air.

Light-coloured curtains or blinds kept closed during peak sunlight will reflect rather than absorb heat.

Avoiding ovens and other heat-generating appliances during the day, placing a bowl of ice in front of a fan, and switching to breathable cotton or linen bedding can also make a noticeable difference in comfort.

As Britain faces yet another bout of extreme summer heat, following these simple ventilation strategies could be the key to cooler nights and calmer days without racking up your energy bill.