The German city of Hannover initiated, in 1990, an ambitious redesign project of the tramway road system. Well in advance of the World Expo, which was to be held in the city in 2001, nine prestigious architects and designers from around the world were invited to freely select a stop in the city and design its canopy. The project was named Busstop and included participants such as Ettore Sottsass, Frank Gehry, Iosa Ghini, Alessandro Mendini, and Jasper Morrison.

The location we chose was a wide tree-lined boulevard where the Tiergarten stop was located, a stop that, due to its usage, needed to be of considerable size. The existing canopy had caused several linden trees to be cut down, and my initial intention was to create a project that would allow their replanting. Together with the civil engineer Jesús Jiménez, we envisioned a rectangular roof supported by two central pillars that served also as downspouts. The roof curved in a series of ruled surfaces –probably inspired by the schools of the Sagrada Familia by Gaudí– that allowed to direct water toward these central pillars, while keeping the entire outer perimeter completely horizontal. These sorts of conoids were made of wood on the underside and copper on the upper side. The absence of perimeter pillars facilitated access to the trams. The central glazed skylight allowed enjoying the views of the sky and the tops of the linden trees.

The result was very satisfying, both for the German city and for us. However, we were very aware that the device we had designed had infinite possibilities: having a horizontal perimeter directing the water inwards, it was a module capable of being uninterruptedly attached to others, both longitudinally and transversely