An airport cooled by natural ventilation: Réunion's Roland Garros terminal

At the arrivals terminal of Roland Garros airport on Réunion, floor-to-ceiling windows frame the green mountains of this French island in the Indian Ocean. The island lies in the tropics, just off Madagascar, so travellers might expect the chill of air conditioning. Instead, the terminal is cooled by a light tropical breeze, produced by natural ventilation built into its design.

The bet against air conditioning

The project began in 2016, part of the airport operator's effort to cut carbon dioxide emissions. Marc Delanoë, then head of its environment and energy team, was determined that the new arrivals terminal would do without air conditioning. "I took on the responsibility to prove to my management that not using air conditioning was feasible," said Delanoë, now the airport's sustainable development director. "It was a risky bet, but our studies kept proving us right."

How the design works

The terminal opened in 2024. Its roof curves upwards from both long sides of the rectangular building in gentle waves, but the halves end abruptly instead of meeting in the middle, forming a "canyon". The resulting low-pressure area funnels wind through vents on each side, adjusted according to the weather, while 7.5-metre ceiling fans help circulate the air.

In the humid 30C heat of Réunion's wet summers, from around November to April, the breeze reduces the perceived temperature by four to five degrees, close to the level usually set for air conditioning. In the dry winter, less air flows in as coastal daytime temperatures fall to 25C, and the building is closed up during cyclones.

Cost and savings

The terminal cost €75m, of which €15m went on a new baggage sorting system and €60m on the building. Since it opened two years ago, the airport has saved €150,000 a year in energy bills. AIA Life Designers says that is about 60% less than an air-conditioned building, with carbon emissions lower by a factor of eight.

Delphine Robert, who works in the terminal once a week for the local tourism board, calls it comfortable: "It's very airy. A lot of light, the ventilation is optimal."

Why it won't work everywhere

The approach is harder to copy in large, polluted cities in mainland Europe, said Delanoë, because pollutants would concentrate inside. Continental Europe would also have to use less air conditioning for natural ventilation to deliver comfort. "If you cut air conditioning from your life, 30 degrees in the office won't feel hot. In La Réunion, people are used to 30 degrees," he said.