Conceived as the new ‘gate’ of Vienna’s business district on Danube Island, the asymmetrical DC Towers are home to an extensive mixed program of uses, from offices to a restaurant through a hotel and private apartments. The first of the two constructions rises 220 meters (250 with the antenna) and was built with a solution based on the tube, formed by a core of reinforced concrete – containing the vertical circulation cores – and a grid of pillars on the facade. The floor plan’s being rectangular and having a narrow bay organizes the inner space in two distinct zones, in accordance with a polarity of uses reflected in the building’s appearance as well, oriented as it is toward a plaza between the two towers. While the outer face and the sides of the buildings have a flat skin, the inner facade has undulating faceted glass planes subjected to the effects of light through the hours of the day and the seasons of the year.