The office high-rise Andreasturm is situated on a triangular plot of land that has become available between the spread of railway tracks at Oerlikon station. The pentagonal tower, the property of the Swiss Federal Railways, is 80 m high, with 22 above-ground and four below-ground storeys.
Precisely placed cantilevers on the 12th floor divide the building into a middle and a head section, making it look slender or flat from a distance, depending on one’s vantage point.
An expansive base anchors the structure in its surroundings and opens it up on three levels. The main entrance with public facilities and a small, new plaza face the traffic-calmed Andreasstrasse. The premises of anchor tenant Amstein + Walthert are accessed directly from the higher railroad platform while the delivery entrance is on the lower street to the rear.
A well-appointed, double-height lobby welcomes tenants and visitors, who reach the upper stories via the lift lobby. An open staircase leads up to the first floor and the main tenant‘s reception desk. The tenant’s public spaces are arranged around a central core: a “piano nobile” with conference rooms, a gallery and a staff restaurant in the protruding portion of the base.
The skeleton of the high-rise is reinforced concrete with a double-shell element façade. Flat slabs span up to 9.30 meters between the core and the prefabricated concrete supports along the façade. The column-free spaces allow for flexible layouts and workplaces with natural daylight. The double-shell façade consists of an inner layer with slender windows that can be individually opened, and exterior glazing with horizontal parapet bands, into which copper and gold coloured inlays have been laminated, their tone varying to match the angled surfaces of the façade. The appearance of the building changes depending on the weather and lighting: at times, the tower may look like a flat, reflecting surface; at others, one can see the filigree vertical structure of the interior.