As the UK faces increasingly frequent heatwaves, experts suggest adopting Mediterranean-style cooling techniques to keep homes comfortable. Dr. Rosa Schiano-Phan, co-author of The Architecture of Natural Cooling, recalls a seminar in the late 1990s where it was predicted that London's climate would resemble Marseille's within 30 years. That prediction now feels accurate, and she advocates for simple, low-energy solutions.
One of the most effective methods is painting roofs white. Studies show that white surfaces reflect sunlight, reducing internal temperatures by 1°C to over 4°C, and can lower surrounding outdoor temperatures by up to 2°C. This helps counter the urban heat island effect, where cities become hotter than rural areas due to heat-absorbing materials.
However, these strategies work best in combination. Shutters, external shades, and keeping windows closed during the hottest hours enhance the cooling effect. Heavyweight walls and floors, which store coolness from night air, also help maintain comfortable indoor temperatures, explaining why Mediterranean homes often stay cool in extreme heat.
Night-time ventilation is crucial, but only if outdoor air cools down. In cities with strong urban heat island effects, reflective roofs and avoiding waste heat from air conditioning become more important. Concerns about white roofs making homes colder in winter are minimal, especially with good insulation, as winter sunlight is weak and often blocked by clouds.
Repainting a house white is not excessively expensive, and many UK homeowners already choose white finishes. For flat or low-pitched roofs, reflective coatings can be applied at low cost. For steeply pitched roofs, replacing dark tiles with reflective clay tiles is more effective, though costs start from about £125 per square metre. As the climate changes, these simple design strategies can help keep homes cooler and cheaper to run.
