A 123m long building extending along the river Sihl on Kasernenstrasse southwest of Zurich central station was built between 1927 and 1930 by brothers Adolf and Heinrich Bräm. Its shell, a reinforced concrete structure with a beamless floor slab and mushroom ceilings of 26cm, spanning up to 9.5m, was designed by Swiss engineer Robert Maillart. In 1930, these post offices were put into operation using extensive conveyor belt systems.
Today, the Sihlpost holds historical importance and is a protected landmark. It is part of the Europaallee development by the Swiss Federal Railways, renovated and converted into rentable commercial premises between 2013 and 2015.
Google is further expanding its Zurich location for its engineering teams, leasing a total area of 60,000m2 in Europaallee. The first phase of this expansion was the Sihlpost, which had an interior fit-out over four floors and a total surface area of 5400m2 for 300 workstations.
In addition to office space, the protected structure featured about 30 meeting rooms, a restaurant, three micro-kitchens, areas for informal discussions, and a lecture room for approximately 100 people. The architectural concept, implemented by Spillmann Echsle, spans the typology of post office buildings and logistics.
The post office style of the reception and restaurant incorporates grey wooden paneling, wooden framed partition walls with rippled glass, and brass features, while the meeting rooms resemble wooden shipping crates that simultaneously separate each level into quiet work zones from the long service corridor. The coordination and integration of partially visible building services with the architectural design are crucial.