Rhythmus im Raum [Rhythm in Space] by Max Bill (*1908, Winterthur, CH, † 1994, Berlin, DE) was specially designed for the courtyard where it stands. This sculpture is an extensive work that both relates to and sharply contrasts with the precise structure of the building's facade as designed by Kurt Ackermann. The piece's ornamental structure is composed of modules developed by Bill based on the average size of a person when seated. The dimensions of the modules, which each feature a horizontal part making an ideal seat, are calculated by multiplying the average by a factor of five. The sculpture is built of light grey Bavarian granite so that its colour and texture complement the smooth white facade of the surrounding office building. Free-standing sculpture is just one of the forms of expression used by Bill, who also worked as a designer and theorist. As an advocate of the theory of constructivism, Bill's endeavours, be they in the area of industrial design or fine art, were always created in line with the notions of concrete art: all of his works were developed using the most rigorous principles of mathematics, as exemplified by Rhythmus im Raum.