The Sphere is a sculpture designed by Mario Bellini for the lobby of the Deutsche Bank head office in Frankfurt, Germany. A spherical network with a diameter of sixteen meters spans between the twintowers. This paper describes the ollaborative design process of architects, engineers and contractor. The various geometrical implications from design synthesis to fabrication and the exchange of information between the different parties are discussed. The concept of a spherical network was transformed into a series of sixty intersecting rings that act together as one sculptural and structural object. The ring configuration is derived from an evolutionary design process that includes geometrical and structural fitness criteria. Evolutionary design, structural analysis and fabrication demanded different geometrical representations that addressed the various constraints emerging during design and construction.