On the day the Commerzbank opened in 1997, the Financial Times adopted it as the symbol of Frankfurt, just as it features Big Ben and the Eiffel Tower as symbols of London and Paris. Natural ventilation of the offices and creating a comfortable internal working environment despite the high wind speeds is achieved by the aluminium façade.

At fifty-three storeys, the Commerzbank is the world’s first ecological office tower and the tallest building in Germany. The outcome of a limited international competition, the project explores the nature of the office environment, developing new ideas for its ecology and working patterns. Central to this concept is a reliance on natural systems of lighting and ventilation. Every office in the tower is day lit and has openable windows, allowing occupants to control their own environment, resulting in energy consumption levels equivalent to half those of conventional office towers. The Commerzbank is clad in carefully detailed anodised aluminium rain screen panels. Foster + Partners made certain that the gain of the rolled aluminium sheets always has the same orientation on each façade. Natural ventilation is achieved on this fifty-three storey office building by a double façade with openable internal aluminium windows. The ability to incorporate complex details into purpose made aluminium extrusions, which frame the outer skin of the façade, facilitates natural ventilation, creating a comfortable internal working environment despite the high wind speeds encountered on a tower of this height.

The plan of the building is triangular, comprising three petals – the office floors – and a stem formed by a full-height central atrium. Four-storey gardens are set at different levels on each side of the tower, forming a spiral of landscaping around the building, and visually establishing a social focus for village-like offices clusters. These gardens play an ecological role, bringing daylight and fresh air into the central atrium, which acts as a natural ventilation chimney for the inward-facing offices. The gardens are also places to relax during refreshment breaks, bringing richness and humanity to the workplace, and from the outside they give the building a sense of transparency and lightness. Depending on their orientation, planting is from one of three regions: North America, Asia or the Mediterranean.