Contrary to what you might think, it was not megalomania that made the city silo possible, but rather sustainability and logistical demands. First, the basics: Swissmill Tower was built as an extension to the historic city mill. Traditionally, this mill used rail transport for distribution. The new silo tower continues this tradition, covering 30% of the national grain demand. Four times a day, a fully loaded grain train leaves the silo in direction of nearby Hardbrücke Station. This explains the location, which may seem unusual at first. As for the concrete: grain silos of this size must be completely sealed to prevent dirt and vermin from entering. This requires a joint-free construction. Only concrete can do this job. The uncompromising industrial aesthetic was specified by the client, Coop. In the lower section, vertical strips reference the colours and dimensions of the old city mill. The south side of the tower serves as a vertical solar plant. At the time of completion, its eight panels comprised the tallest solar facade in Europe.