Kevin McCloud: How a mop will keep your Grand Design cool in summer

Kevin McCloud from Grand Designs standing outside a new wooden building
Kevin McCloud is returning for a brand-new series of Grand Designs on Channel 4, on Wednesday 31st August at 9pm (Image credit: Malgosia Czarniecka Lonsdale / Channel 4)

Kevin McCloud has revealed his top tip for keeping your home cool in the summer months — use a mop.

The Grand Designs presenter says rather than paying for home air conditioning, mopping your floors or patio in the morning and leaving the water there to evaporate can have a cooling effect. 

McCloud claims this is the reason you find water on the pavement outside older people's homes in villages in Italy.

"They’re not doing it to keep clean. The water evaporates; to do so it draws energy from its immediate environment. So, sun heats water, water evaporates off, stone becomes cool. Air passing over stone into house becomes cool," he told Radio Times.

Rather than paying circa £3,000 to cool your home or leave yourself to swelter, he says it's about using "basic physics". Water on the floor works in the same way as evaporative cooling in air conditioning units, he explained. 

McCloud's simple solution to large-scale glazing 'causing overheating'

This gives a simple, eco-friendly solution on how to keep a house cool in summer. Of course, using a mop to do that comes without the price tag too.

Sitting under a tree gives the same effect, he added, because the water evaporates off the leaves to give evaporative cooling.

McCloud, who is returning to our screens soon for the 23rd series of Grand Designs on Channel 4, also had something to say about whether homeowners should continue adding glazing to their extensions and self builds after many found their homes overheating this summer.

“Go to Morocco or any hot climate in the world, and there are plenty of buildings with glazing. It’s not the glass that’s the issue. It’s the shading that we need to be providing,” he said.

He suggested rather than pull down all the glazing, people go and buy a Gazebo to shade their glass walls instead as it would sort the problem. Easy.

For those extending, building their own homes or looking to add something a little more permanent, an awning, shutters, an appropriately sized roof overhang or a brise soleil are external shading solutions which can help prevent overheating in homes.

Kevin McCloud stands outside one of the Grand Designs in his next series

The brand-new series of Grand Designs returns to Channel 4, on Wednesday 31st August at 9pm (Image credit: Malgosia Czarniecka Lonsdale / Channel 4)
Amy Willis

Amy spent over a decade in London editing and writing for The Daily Telegraph, MailOnline, and Metro.co.uk before moving to East Anglia where she began renovating a period property in rural Suffolk. During this time she also did some TV work at ITV Anglia and CBS as well as freelancing for Yahoo, AOL, ESPN and The Mirror. When the pandemic hit she switched to full-time building work on her renovation and spent nearly two years focusing solely on that. She's taken a hands-on DIY approach to the project, knocking down walls, restoring oak beams and laying slabs with the help of family members to save costs. She has largely focused on using natural materials, such as limestone, oak and sisal carpet, to put character back into the property that was largely removed during the eighties. The project has extended into the garden too, with the cottage's exterior completely re-landscaped with a digger and a new driveway added. She has dealt with de-listing a property as well as handling land disputes and conveyancing administration.