The Catholic Social Institute of the archiocese of Cologne was founded on 18 October 1947 by Josef Cardinal Frings as a "place of further education for adults based on Catholic social teaching". The house is one of the conference centres of the Archdiocese of Cologne. From 1952 until the beginning of 2017, the KSI was located in Bad Honnef. Since April 2017, the new location is on the Michaelsberg in Siegburg.
The Catholice Social Institute openend its doors in May 2017 in the modernised and expanded building of the former Benedictine Abbey on the Michaelsberg in Siegburg. A new builidng was constructed on a car park below the monastery, which is connected to the previous monastery via two bridges. The new buliding (Forum) houses a restaurant and conference rooms, offices and two parking decks for the Catholic Social Institute. The forum creates a new unit that is based on the old monastery building, but nevertheless sets a new architectural accent.