A Retrospective Look at 50 Years of the Outdoor Testing Field in Holzkirchen

FOUR YEARS AFTER the end of World War II, the Federal Republic of Germany emerged from the amalgamation of the three western occupation zones. One year later – in April 1950 – the first housing law was enacted. This development stipulated the building research. Prof. Dr.-Ing. Hermann Reiher, the founder of the Fraunhofer Institute for Building Physics – at that time it was called Institute for Technical Physics Stuttgart – used this opportunity for research as incentive to propose setting up an outdoor testing field to the Federal Ministry of Transport, Building and Housing. Under realistic climatic conditions, test buildings, with walls consisting of different materials, were to be tested for their hygrothermal performance during simulation of long-term effects of housing. The ministry financed the setting up of six test buildings. The masonry of one of those houses consisted of 11⁄2 brick walls, a standard at that time. Another 20 test buildings were set up on behalf of building materials associations and building materials producers. In the summer of 1951 the construction of these test houses began on a vacant site in the foothills of the Alps close to Holzkirchen. Already in 1952 the first experiments were carried out. (Figure 1). The main goal of these experiments was to settle the question whether it is necessary to reckon with moisture related characteristics of building materials – besides thermal insulation of building components – also. It was