With the moving of the federal government, the Catholic church also wanted to relocate their diplomatic offices to Berlin. For the new building they chose a real estate in the district of Neukölln with an immediate adjacency to the neo-Romanesque basilica of St. John, the largest Catholic church building in Berlin. The building consists of two staggered rectangular parts which skillfully use the triangular shaped area. The narrower front building hosts accommodation rooms and a chapel, while the broader building at the back attends administrative functions. The core of the composition is the central reception hall. This follows the extension of the church's transept, and with its fully glazed outer wall opens the view onto the northern wall of the transept with its large rosette window.