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Designing Without Air-Conditioning in the Tropics

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Francis Kéré runs his practice in Berlin, far from the heat of his native country Burkina Faso, with typical temperatures over 100 degrees Fahrenheit. But he remembers. Kéré travels between bohemian Kreuzberg, Berlin where he keeps his sustainable architectural practice, and hot and dusty Burkina Faso, Mali, Yemen and India.

His obsession? The heat. When it’s 104 degrees in the shade, the indoor temperature is unbearable. “You can’t move,” he said. “I won’t ever forget that.”

There’s not much electricity to go around, Kéré says. “So there is no air-conditioning. It’s too expensive for a country like Burkina Faso.”

So when he designed this secondary school for Dano in his native land, he built it with innovative, elegant, distinctive and yet simply constructed split-level roofing and ceiling structures that funnel warm air up and out of the buildings.

While still in architecture school in Berlin, Kéré received a prestigious Aga Khan award for architecture for his first building, a primary school in the village of Gando. This is his second school.

For maximum cooling insulating properties he selects locally cut laterite, an iron-rich clay which hardens on exposure to air, to make the bricks. From design to labor to construction, Kéré adapts to local conditions and turns them to his advantage. He uses non-industrial construction techniques.

The roof truss structure was not hoisted by a crane. It was built on the ground in modules and lifted by hand. Members of the community pounded the school floors flat with mallets and polished it with stones, working to the beat of drums. “You cannot destroy it,” Kéré says. “It is durable.”

Tall window slats that can be adjusted control both light and heat. Three to a room, they pull air into the classroom. Heat rises.

To use that movement of air, a series of narrow “chimney” gaps between the convex wave shapes in the highly insulating concrete and brick ceiling pulls the hot air up and out the roof.

Because there is an air space above the ceiling under the tin roof: much less heat than normally would beats down on the building through the roof – and the shaded space creates a wind tunnel, that pulls the hot air through the classroom.

It’s not that the air is going to get much cooler, Kéré explains, but “When you create this physical aspiration, it takes the heat away constantly.”

Source: GreenSource