Oskar Hansen, Lech Tomaszewski, Stanislaw Zamecznik: model of the proposed extension to the Zacheta Gallery in Warsaw, 1958.
Hansen called Open Form a philosophy, a position that defined one's attitude toward reality. The concept, which referred to the theory of sculpture and architecture put forward by Katarzyna Kobro and Władysław Strzemiński, could be construed sociologically as a structure of space shaped by various types of human activities. Hansen always stressed the humanistic element in architecture, never the technological angle. He wrote, "Open Form is about variable compositions – the processes of life highlighted by backgrounds."