Eco-friendly buildings: how next-generation buildings can better withstand heatwaves

Faced with increasingly frequent heat waves, sustainable architecture is no longer just an environmental issue; it is also becoming a public health response. Designed to naturally limit temperature increases, eco-friendly buildings are becoming more common in new construction and are now inspiring renovation projects. High-performance insulation, natural ventilation, green spaces, and bio-based materials all contribute to maintaining better thermal comfort while reducing energy consumption.

The issue has become central in France. According to the Scientific and Technical Center for Building (CSTB), nearly 50% of French buildings, or approximately 10 million buildings, are not adapted to current heat waves. A large proportion of these dwellings are located in urban areas, where urban heat islands further amplify summer temperatures.

A design conceived to keep fresh

Unlike traditional buildings, green buildings primarily rely on passive solutions. Their objective is simple: to prevent heat from entering rather than combating it with air conditioning. This is achieved through enhanced insulation, sun-protected facades, adjustable sunshades, exterior shutters, high-performance glazing, and natural ventilation to remove the heat accumulated during the day.

Materials also play a crucial role. Wood, raw earth, hemp, and stone all possess high thermal inertia. They absorb some of the heat during the day before gradually releasing it as temperatures drop at night, thus limiting heat spikes inside homes.

The RE2020 environmental regulations, applied to new construction in France, now require that summer comfort be taken into account from the initial design stage. Architects must incorporate criteria designed to limit the risk of overheating, without relying solely on air conditioning.

Green roofs, green facades and smart ventilation

Green buildings are also incorporating numerous innovations. Green roofs can reduce the temperature of sun-exposed surfaces, while planted facades limit direct sunlight and improve residents' comfort. Some residences also collect rainwater to automatically irrigate these green spaces during the summer.

In addition, intelligent ventilation systems can automatically open certain parts of the building at night to take advantage of cooler air. Sensors continuously measure the indoor and outdoor temperatures to optimize air exchange without any intervention from the occupants.

Buildings certified according to the international "Passive House" standard go even further. Thanks to an extremely high-performance building envelope and controlled airtightness, they require very little energy for both heating and cooling, while offering a high level of thermal comfort throughout the year.

A response to rising temperatures

The heatwaves of 2026 brought building adaptation back to the forefront of public debate. Experts believe that passive solutions can lower indoor temperatures by several degrees and delay, or even eliminate, the need for air conditioning in many homes. They remain a priority for energy renovation policies, even though some situations now require supplementary active cooling.

Beyond improving residents' comfort, these buildings also help limit electricity consumption during heat waves. This has become a strategic issue as heat waves become more frequent across Europe. According to experts, adapting the building stock is now one of the main challenges of the coming decades in addressing climate change.