The French are painting their windows with chalk to beat the heat
In response to rising temperatures, people in France are using chalk paint on their windows as a low-cost, effective method to reflect sunlight and reduce indoor heat. The practice, which can lower indoor temperatures by several degrees, has gained popularity as an alternative to air conditioning during heatwaves.
Background
- The article describes a growing trend in France where residents paint their windows with a chalky, reflective coating to reduce indoor temperatures during heatwaves — a low-tech response to a warming climate.
- France has experienced increasingly intense summer heatwaves, culminating in a record 46.0°C (114.8°F) in 2019. Many older buildings lack air conditioning, and retrofitting is expensive or restricted by historic-preservation rules.
- The technique repurposes "blanchiment" (whitewash), traditionally used on farm buildings and greenhouses to reflect sunlight. Modern versions are water-based, removable, and marketed as a cheap alternative to AC or window film.
- The practice has spread via social media and local climate-adaptation campaigns, particularly in cities like Paris, Lyon, and Bordeaux, where heat-island effects and rooftop-heavy architecture intensify temperatures.
- Critics question durability and aesthetics; proponents see it as a scalable, low-carbon adaptation measure that ordinary households can deploy without permits or professional help.