The collection of the baudenkmal bundesschule bernau association is probably the largest collection on the former ADGB Trade Union School. It includes objects and documents on the over 90-year history of the Bauhaus ensemble and its extension buildings from 1927 to the present day. It mainly includes photographs documenting the construction and use of today's UNESCO World Heritage Site as well as copies of most of the building plans from the years 1928 to 2007. The originals have for the most part already been handed over by the association to the Federal Archives (Bundesarchiv) in Berlin, where they are kept under the name SAPMO (Foundation Archives of Political Parties and Mass Organisations of the GDR in the Federal Archives). In addition, the collection also includes exhibits on the building's construction history over the decades, especially furnishings of the Trade Union School and the associated teachers' residences, from the period between 1930 and 1933 and from the socialist-influenced period between 1947 and 1989, as well as publications, dissertations and writings on the building and history of use for the Trade Union School, some of which are rare and some of which are unpublished.

The collection was established in 1990 after the founding of the baudenkmal bundesschule bernau e. V. by the founding fathers and former Trade Union College employees from the history department. The aim was to comprehensively document the history of the building ensemble – from the planning and furnishing of the Trade Union School by the Bauhaus to its current use. The first exhibits came from the holdings of the Trade Union College. In addition, there were purchases, donations of estates and collections of former Trade Union School employees or course participants, as well as finds recovered during the extensive renovation work on the Trade Union School and the teachers' residences.