The former SBB service building at Langstrasse 175 in Zurich is about to be repurposed. It is to be renovated in line with sustainable building principles and extended with an annex. Despite a minimally invasive concept with consistent reuse of the existing components, the project was not successful in the competition.
The brief called for the development of a project proposal that would upgrade the existing SBB service building from the 1960s, its extension from the 1980s and the urban axis. The building block is to be developed into an important urban axis on Langstrasse. The new utilisation concept focuses on retail and gastronomy on the ground floor and office, educational and healthcare use on the upper floors. An extension on the courtyard side has utilised the utilisation reserve and created additional rental space.
New materials were avoided wherever possible and at the same time existing materials and components were consistently reused. The façade is only to be upgraded where necessary. The elements of the façade cladding that are no longer required due to modifications are used for the extension. New building technology was also actively avoided, so the building mass is passively cooled. A timber construction was combined with hempcrete insulation for the extension.
In order to keep grey emissions as low as possible, the basement was not extended, which at first glance seemed logical for the spatial organisation. This also means that the plane tree can be preserved, which has qualities right next to the railway track – visually, for people to stay in, but also to reduce heat.
The project proposal also suggests a change to the traffic regime in order to resolve the cramped and unattractive situation around the north-eastern corner of the building. By creating a 20-metre meeting zone in Röntgenstrasse, pedestrians and cyclists can be separated.
