The competition entry for the new construction of the football stadium for the Karlsruher SC was planned as a complete conversion during ongoing operations. Together with the architects of HPP, Knippers Helbig developed the concept for the concrete bowl and roof construction as well as the roof covering and facades. The "stadium bowl" is designed as an encircling one-tier stand, in which identity-forming, external columns as upstream reinforced concrete wall panels form both part of the frame of the grandstand construction as well as the support of the cantilevered steel roof construction. The main building is integrated in the west grandstand and includes all functionalities for the operation of the stadium. The roof structure of the stadium is planned as a construction of welded hollow box girders, which dissipate into a truss girder. The position of the main girders develops from the radial geometry of the stadium bowl with a regular column axis grid. A speedy and flexible step-by-step construction process was guaranteed, due to the high degree of prefabrication of the aligned structure, without elaborate connection details and junctions (low maintenance costs).