External shading systems (pictured above) – such as blinds or shutters fitted to the outside of windows – are proving to be one of the most effective tools in keeping indoor temperatures down during hot weather.
Using Loughborough’s matched-pair test house facility, researchers are running side-by-side comparisons of homes with and without external shading.
“We’re looking at how we can adapt our homes to stay cooler in hot weather, without relying on air conditioning,” said Dr Ben Roberts, an expert in indoor environments and building performance.
“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.
“However, it’s a problem when the sun’s heat enters through unshaded windows. Once the heat gets in, it gets trapped.
“So shading the glass from the outside is a very good way to prevent this before the sun’s heat enters.”
The test facility features two identical full-size houses built side-by-side. One is fitted with external shading; the other is not.
The team uses temperature sensors, airflow monitors and “heat boxes” – devices that mimic the warmth of a human body and household appliances – to measure real-world comfort levels in each home.
“We’re not just testing materials – we’re simulating how people actually live,” said PhD researcher Niloo Todeh Kharman. “Overheating in homes doesn’t just cause discomfort – it can pose a real risk to health, particularly for older adults, young children, and people with medical conditions.”
The researchers are supported by several industry partners – including the British Blind and Shutter Association (BBSA), Caribbean Blinds, Guthrie Douglas, Hunter Douglas, James Robertshaw, Serge Ferrari and Weinor – who are providing a range of shading products and materials for testing.
While reflective blinds and light-coloured curtains indoors can help, the team emphasises that external shading systems are more effective because they stop the sun’s heat from ever passing through the glass.
“It’s like parking your car in the shade versus in full sun – the difference is huge,” said Dr Roberts. “And as summers get hotter, we’ll need to rethink how we manage solar heat gain in our homes. That includes designing windows with shading in mind from the start.”
The research comes as data shows that around one in five homes in the UK are already overheating during hot weather – a figure expected to rise as global temperatures climb.
To support households now, Dr Roberts recommends a few simple steps:
Top tips to keep your home cool:
- Use external shading (such as shutters, blinds or awnings) to block sunlight before it enters
- Keep windows closed during the day if it’s hotter outside than inside
- Open windows at night to let in cooler air
- Avoid dark curtains, which absorb and radiate heat – opt for light colours or reflective materials
- Consider secure night-time ventilation, such as grilles or automated systems
“We know that people worry about opening windows at night due to safety, noise, or pollution,” said Dr Roberts. “That’s why external solutions are so important. They let you reduce indoor temperatures passively and securely.”
The Loughborough research is supported by the Chartered Institution of Building Services Engineers (CIBSE) and aims to provide low-cost, low-carbon solutions to make UK homes more resilient to extreme heat.
“Ultimately, this is about future-proofing,” said Dr Roberts. “External shading should be a standard part of how we design, retrofit, and live in our homes. It’s not just about comfort – it’s about health.”
Video (downloads and embed codes): HEATWAVE: One-in-five homes not equipped to handle hot weather
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