The world's first building made entirely of non-metallic reinforcement was constructed in Dresden, Germany in 2022. It will be 220 m² in size and represents the entire process chain of carbon reinforced concrete construction. In Germany's largest construction research project C³-Carbon Concrete Composite, the topic of carbon reinforced concrete and its implementation have been researched and tested since 2014. All the research results were culminated in a lighthouse project, the C³ technology demonstration house CUBE. Based on these results, the boundary conditions for material, form and construction were derived and the necessary structural, experimental and design verifications were provided as well as the approvals for the construction of the building were granted. This paved the way for further new construction projects. Originally planned as an actual cube, architect of HENN Architects gave the CUBE a bit of a twist. And so, an interplay of two essential elements was created: the double-curved striking TWIST shells and the clearly structured BOX. In order to successfully realize the demonstration house CUBE, science and industry combined their competences in carbon reinforced concrete construction. Above all, the BOX precast complex demonstrates the extraordinary and immediate application potential of this composite material. The BOX, described in this paper, consists of semi-precast wall elements and precast slabs that can be manufactured with component thicknesses of just a few centimeters due to the use of carbon reinforcement. Manufacturing technology was tested in an automated precast plant and assembly was implemented at the construction site.