The second International Congress of Modern Architecture (CIAM), initiated by Le Corbusier in 1928, addressed an issue that was topical at the time: “the minimumexistence apartment”. It took place in Frankfurt in 1929. CIAM II thus represents a decisive chapter in modern urban planning: it formulated criteria, standards and working methods which defined architecture until long after the war. Eighty years later, architectural historians and architects met to look at the historical circumstances surrounding CIAM II, also addressing the matter of how social dwelling space is composed today. They examined the innovative media presence of the congress and the basic demands on apartment building that were defined then and have been transformed today. Reflection on the past and taking inventory of the present makes architectural history more concretely comprehensible and modern architecture therefore more consciously appreciable.