The university of Zurich does not only share an acute lack of space due to constantly increasing numbers of students with most other universities, but also only a limited reserve of inner city sites for the badly needed expansion and additions. The required space therefore has to be gained mainly by compressing the spatial capacity of the existing buildings, by creating new space in an existing ambience - a house within a house, so to speak. In view of the diverse aims of the interest groups involved, the revitalization of the university posed a challenge to the architects' ingenuity.