As punishing heatwaves become a fixture of European summers, architects are making the case that the answer is not simply more air conditioning, but smarter buildings. A residential project in Montpellier, in southern France, has become a showcase for design that keeps interiors cool through the structure itself rather than through energy-hungry machines.
The Montpellier example
The development, named Secret Gardens and designed by the studio Vincent Callebaut Architectures, was built on the site of a former military school and includes well over a hundred apartments, France 24 reported. Its designers say indoor temperatures stayed comfortable through recent heatwaves, largely without air conditioning. The building leans on old ideas as much as new ones: latticed screens, echoing the mashrabiya of traditional Middle Eastern architecture, that let air through while blocking the sun; curved facades that shade the walls; and deep, recessed balconies that create cool outdoor space.
How passive cooling works
These techniques fall under what engineers call passive cooling, keeping heat out and letting it escape without mechanical help. The toolkit includes cross-ventilation that draws breezes through a home, green roofs and planted walls that shade and cool by evaporation, heavy or specially designed materials that absorb heat during the day and release it at night, and careful orientation and shading to limit direct sun, the European Commission's BUILD UP platform notes. Combined thoughtfully, researchers say, such measures can cut the need for mechanical cooling substantially.
Why it matters
The stakes are large. Cooling already accounts for a significant and fast-growing share of the world's electricity use, and demand is climbing as the planet warms and more people buy air conditioners, researchers at the University of New South Wales have argued, warning that the world cannot simply air-condition its way out of a hotter future. Air conditioning also has a cruel feedback: it pushes heat outdoors and strains power grids exactly when demand peaks, and it fails during the blackouts that heatwaves can cause. Passive design keeps working when the power does not, and can help people in places where air conditioning is unaffordable.
Not a silver bullet
None of this means air conditioning disappears; on the most extreme days, and for the vulnerable, mechanical cooling still saves lives, and the most efficient systems, run on clean power, have a role. The argument from projects like the one in Montpellier is that buildings should be designed to need far less of it. As heatwaves shift from exception to expectation, its advocates say, cooler-by-design housing is less a novelty than a necessity, and one that existing techniques already make possible.
