From more than a century ago, during the industrial revolution, cities started to change. With the growth of the urban population, the ancient towns were becoming too small and inefficient. They started to sprawl, and some cities fused together to become megacities. Many forests, savannas and lakes were destroyed to make place for buildings and roads. Many species went extinct because of this. But also, with the cities now larger, there is an increasing need for cars and other vehicles, causing traffic, but also pollution. The urban growth is one of the major factors of the global warming, the natural destruction and also the pollution of the food and the water.

Nowadays, cities are still growing at an incredible rate, all around the world. The phenomenon is expected to continue during the next decades. The east coast of the United States and the Western part of Europe are expected to become one megacity. Urban growth is one of the major preoccupations of the current and next generations, and currently architects and urbanists are looking for solutions.

But while we can’t stop populations from growing and we must create new shelters and new spaces, we can stop the sprawl by densification. And that means creating higher buildings, but also, digging deep underground, and creating extensions to the cities under the current ones. This will keep the distances relatively short between the different spaces and reduce the need for cars or transport. But while this solution seems promising, one challenge still remains, how are we going to provide natural light deep underground? In this project, we propose a light tunnel, which will transport the light from the top of the building, and carries it to the basement and finally diffuse it in the rooms underground. Theses light tunnels are very flexible and can be used even in old buildings. They can be assembled in the staircase and in the ceiling and provide a diffused natural light even in the deepest parts of a building.