The fourth phase building completes the new federal administration site.

The administrative building of the fourth phase serves as the keystone of the new site for the federal administration. This eight-story structure is positioned on the side of the site facing Zollikofen train station, adjacent to a small square. Although smaller in volume than the other three buildings, the fourth structure asserts itself within the ensemble through its striking façade made of mineral material. Like the other administrative buildings, the spaces are arranged around an inner courtyard. This courtyard forms a glazed atrium within the double-height ground floor, flooding the entrance area with natural light. Six of the seven upper floors house a variety of office and meeting spaces, as well as interaction zones. The top floor features conference rooms and a restaurant with panoramic views over the site and the adjacent railway infrastructure.