The C³ project (Carbon Concrete Composite) is currently one of the largest research projects in the German construction industry. A significant number of results of this project are brought together in the C³ technology demonstration house “CUBE” which is assumed to be constructed of steel and both glass and carbon reinforced concrete members. This paper introduces the design and development of the house's roof shell. For that, the software solutions Rhinoceros 3D + Grasshopper 3D were used as the main algorithmic environment. Methods and specially developed tools that were used to model and compare multiple structural solutions of the load-bearing shell as the main part of the roof are presented. The paper additionally describes an overview of the important aspects that are of particular interest within the CUBE project which are part of the key works, such as the design workflows and manufacturing strategies of the appropriate shape of the formwork, as well as of the insulation and biaxially oriented carbon reinforcing grids.