C. H. Boehringer Sohn had the thoroughly run-down property renovated from the ground up as a representative residence for a member of the company's board. When work had already proceeded to a great extent, the main and side buildings burnt down to the foundations and outer walls on 1 September 1971. The question of guilt was never settled. Under the monument authority's strict conditions, C. H. Boehringer Sohn built the Castle Mill anew. From 1976 to 2000, the main building was used for presentations and seminars. Since 2000 it has housed the office of the business association's and shareholders’ foundations: Boehringer Ingelheim Fonds, foundation for basic medical research; Boehringer Ingelheim Stiftung; and Geschwister Boehringer Ingelheim, foundation for the humanities.