The new building will be constructed behind the preserved historic facade on the site, which is only 17 meters wide but 65 meters deep.
The concept is based on the requirement that the extension of 58 rue Belliard be used by two separate parties. The ground floor and basement are predominantly used by the state representative office. The new front building will be used primarily by the Goethe Institute or, in smaller areas, by third-party tenants of Baden-Württemberg companies.
Inside, the integration of a new garden courtyard has ensured that all public spaces on the ground floor have natural lighting and an outdoor connection. The reorganization of the floor plan allows for a variety of internal connections. All parts of the building are interconnected and can be used together for large events. The green roofs and the regenerative energy supply with drilled piles for geothermal use stand for the sustainability of the new building.