How an Architectural Gem from 1900 Became “Building of the Year 2020”: Alter Wall 2-32 at the Heart of Hamburg, Germany

The listed building complex Alter Wall 2-32 built in 1910 is located at the heart of Hamburg between the landmark City Hall and the canal Alsterfleet tunneled by the railway. During the extensive revitalisation and structural expansion the historic building substance had to be preserved and reused for load bearing as extensively as possible. The listed historic facades were secured by a spatial steel structure, which was reintegrated for load transfer after the erection of the new supporting structure. Behind the historic facades five new basement floors were built under the protection of a deep trough pit withstanding high water pressures and avoiding any but slightest deformation during the excavation process. About 10.000 m2 of retail space and around 18.000 m2 of office space were created. For these efforts the planning team won the “Building of the Year Award” in 2020.