In Dessau, the Bauhaus experienced an extremely productive phase in 1925 –1932. In this period a number of buildings were constructed in the city, which are summarised under the name Bauhaus Buildings. The materiality of these buildings, from which important impulses for the development of architecture in the 20th century emanated, is just as important for a comprehensive understanding of the buildings as it is for their long-term preservation. The Bauhaus Dessau Foundation has had a building research archive since 1998, in which building materials and components of the Bauhaus buildings are preserved. Using selected materials such as concrete, Torfoleum or stonewood screed as examples, aspects of researching and preserving these buildings are discussed using the Bauhaus building, the Masters’ Houses and the Dessau-Törten housing estate as examples.