Some of the old buildings used by Freie Universität are interesting on account of their architecture, their cultural significance and their history. Several of the buildings of the Kaiser Wilhelm Society were designed by Ernst von Ihne, the architect of the State Library on Unter den Linden and the Bode Museum; others by the architect Carl Sattler, from Munich. Others were once office buildings, like the Reichsknappschaft insurance society building by Max Taut and Franz Hoffmann. Many of the buildings of greatest historical interest lie within an area of barely a square kilometer.
In 1948, Freie Universität moved into the former premises of the Kaiser Wilhelm Institute (KWI) of Biology at No. 3, Boltzmannstrasse, built in 1916, which became its first main building. Today, this is used mostly by the Department of Law. Other old buildings joined it, ranging from the former KWI of Chemistry, closely linked to the names of Lise Meitner and Otto Hahn, to those with a disturbing past such as the KWI of Anthropology, Human Heredity Studies and Eugenics. The latter now houses part of the Otto Suhr Institute. Student numbers grew rapidly, making it necessary to expand the teaching facilities, which meant that after a short time, new buildings were being planned.