Heatwave: this simple trick can lower the temperature of your home by 6°C

 

As a heatwave sweeps across parts of France, and several deaths are unfortunately reported, here are some simple tasks to cool down your home.

For the past 48 hours, a veritable "heat dome" has descended upon France. Throughout the country, Météo France has recorded record temperatures, and it's not over yet. This situation is exceptional due to its early arrival at this time of year. Temperatures are barely tolerable for 55% of the French population, due to " poorly insulated , poorly ventilated housing lacking sun protection and outdoor spaces," lamented the Housing Foundation (formerly the Abbé Pierre Foundation) in a study published last summer.

On June 26th, the Housing Foundation presented new figures on " summer energy poverty." This "emergency" situation led the Foundation to collaborate with members of parliament from across the political spectrum (Ensemble pour la République, Ecologists, Socialists, La France Insoumise) on a bill aimed at accelerating the renovation of "heat pump" homes, a term used to describe poorly insulated dwellings rated E, F, and G on the Energy Performance Certificate ( EPC ). The bill will be submitted to the National Assembly on June 25th.

Heatwave: This seemingly good idea to cool your home could one day cost you dearly

LED lighting and ceiling fans

While the Housing Foundation last year likened unheated apartments to "the absolute minimum of public action," Housing Minister Valérie Létard wants to update the Energy Performance Certificate (EPC) to better incorporate the concept of summer comfort. The ministry is expected to formulate proposals in this regard this summer. In the meantime, you may regret having postponed installing air conditioning in your apartment again due to the cost. But you're forgetting that "there are a few simple tips and tricks that have allowed us to achieve a difference of 7 to 10 degrees Celsius between the outside temperature and the temperature inside a home during the summer," emphasizes the home renovation startup Little Worker.

Start with the basics: limit heat emissions , especially the significant amount coming from household appliances. For example, avoid running the washing machine and dishwasher in the blazing sun at 3 p.m.! And opt for LED (light-emitting diode) lighting, which gives off less heat than traditional light bulbs. Think the ceiling fans your in-laws have installed in their living room are outdated? Think again. "Thanks to its blades, the ceiling fan circulates cool air and quickly cools the room, down to -6 degrees Celsius ," assures Little Worker, praising it as an "ecological, quiet, and aesthetically pleasing solution ," whether you like it or not.

Heatwave: This forgotten solution cools your home at a lower cost

Blackout the windows

More broadly, ventilation , "often neglected, allows, thanks to controlled airflow in the home, for the regulation of air humidity and true comfort throughout the year ," assures Little Worker. So make sure your mechanical ventilation system (MVHR) is working! Another simple measure for staying cool if you're about to move in is "eco-design ." This simply means being careful not to place your bedroom in a room facing due south. Never mind the view of the garden! Don't skip the curtains either, even if it's currently more fashionable to show off bare windows: " Blackout curtains trap heat between the curtain and the glass," the startup reminds us. Blackout curtains also apply to the exterior: Hello Watt, also specializing in energy-efficient renovations, "systematically" offers its clients the installation of shutters.

Regarding the windows themselves, "opting for double glazing is beneficial for maintaining indoor temperatures, both in summer and winter ," Little Worker reminds us. Admittedly, this is a more expensive undertaking, perhaps best considered for the summer of 2026. The same goes for wall and roof insulation, which is nevertheless "crucial for keeping your home cool during the summer ," the startup emphasizes.

Insulate with bio-based materials

This guide suggests investing, "where possible, in bio-based insulation , " which is the most effective for ensuring significant thermal lag, meaning the time it takes for heat to pass through a material. The longer it takes for heat to pass through the insulation, the cooler the home stays. For example, wood wool provides eight hours of thermal lag, twice that of expanded polystyrene.