The central element of the Sony Center is the 4.000 m² roof, covering the market place. It spans 102 m at the main axis and 77 m at the minor axis. The elliptical space in plan is an all-weather gathering place, the social centre of the building complex. The slightly swaying roof construction made of steel, glass and translucent fabric produces interesting lighting effects. The unique form of the roof required the highest technical niveau in installation. The displacement of the centre axis and the swinging form of the perimeter ring bestow upon the roof construction a sense of dynamism. In the centre and at the connections to adjacent buildings the roof is open.