The Laboratory for Research on the Structure of Matter (LRSM), University of Pennsylvania, was built in 1965 as part of the Advanced Research Projects Agency's (ARPA) Interdisciplinary Laboratories (IDL) program intended to foster interdisciplinary research and training in materials science. The process that led to the construction of the four-story structure served as the focus of intense debates over the meaning and process of interdisciplinary research in universities. The location of the building, its size, internal design, and functionalities were all subject to heated negotiations among patrons, scientists, and university administrators, to find the proper place of interdisciplinary materials science on the University of Pennsylvania's campus. Building on the recent work on laboratory architecture, this paper argues that the negotiations and controversies over the LRSM building were concrete representations of the broader struggle over the appropriate place of interdisciplinary research and training within a university.