Forward-looking link to the past. During the refurbishment of the Bundesbahn headquarters at Bismarckplatz in Essen, which has been vacant since 2003, great importance was attached to ecology and energy efficiency. The multifunctional building envelope created there features high-performance solar, thermal and sound insulation glazing that reduces energy consumption to a minimum - supplemented by variable thermal insulation and hollow chamber web technology. Existing building fabric and new façade technology were combined by means of a discreet architectural language, thus reviving the old silhouette of the building by pairing windows modeled on the original construction with the profile slenderness of a mullion-and-transom façade. To this end, above the entrance is a glass-and-steel structure whose glass elements have been imprinted with a motif from the building's historic gable. The completed building will serve Deutsche Bank as a service center.