The temporary multipurpose hall built for the Federal Garden Show in 1975 in Mannheim by Frei Otto and Carlfried Mutschler is considered the largest wooden grid shell construction in the world. Although it was even placed under monument protection in 1998, an international debate about its demolition or preservation is currently underway. Frei Otto developed the complex roof largely without digital calculation methods, using a delicate hanging model: model-making, drawing, and measurement techniques formed the basis for a creative experimental culture, which involved a continuous calibration of eye and hand, scientific observation, and technical skill – a craft-intellectual self-adjustment, in which design could also trigger a collective discourse about the future of society. Based on predominantly unpublished materials from the.