Factory building was a challenge for architects at the beginning of the twentieth century. Material, function and construction were all subject to operational constraints, but also presented opportunities for a strictly modernist architectural grammar: Less is more. The Verseidag Färberei- und Herrenfutterstoffe-Gebäude (the Verseidag building for dyeing and gentlemen’s linings) in Krefeld is the sole factory that Ludwig Mies van der Rohe ever built, from 1930–1931. How this former building related to the context of its times and what has happened to it now will be examined at the 14th Krefelder Architekturtage.