British engineer Tom Greenhill has proposed a low-cost, low-energy solution for keeping UK homes cool in a heatwave: painting the outside of windows with yoghurt.
Painted on with a roller, yoghurt dries quickly and creates a fritted glass-like effect that Greenhill says should reflect light and heat in much the same way as other energy-efficient window coating products.
Greenhill admits that this may seem like a "totally eccentric idea". But based on his own experiments, he is yet to see a downside to the strategy.
Tom Greenhill has proposed using yoghurt as an emergency window coating in heatwaves
He says the yoghurt is easy to apply, doesn't smell, doesn't attract insects, doesn't degrade unless there's heavy rain and can be washed off simply with a cloth and water once the heatwave is over. Greenhill is a chartered engineer and environmentalist, specialised in energy efficiency in new builds, who recently launched a Heatwave Toolkit cataloguing low-cost DIY cooling solutions.
His view is that, while there are some great products and architectural interventions on the market that can retrofit buildings to ward off heat, most are currently inaccessible to many people.
The yoghurt forms a thin coating that looks similar to fritted glass
"I've put green roofs and all these landscaping elements in, specified external shading, deep window reveals, moving external shades," Greenhill told Dezeen. "These are all fantastically useful, but most people don't...