PSP Real Estate AG, Zürich, Switzerland
Burckhardt+Partner, Basel, Switzerland
Jörg Brändlin, Enrico Cristini, Heike Egli-Erhart, Antje Käser-Wassmer, Kata Aletta Orbán, Jacqueline Pauli, Flamin Tröster, Andreas Zachmann
Swiss Solar Award, category ”new constructions“
Prixforix, Swiss Façade Award, 3rd prize
The 22-storey Grosspeter Tower stands at the south-east entrance to Basel, with access to the A2/A3 motorway in the immediate vicinity and the Basel SBB railway station nearby. Beside the streets and tracks, this high-rise projects upwards to a height of 78 m and provides 18,000 m² of floor space for a hotel and offices.
Its shape comes from the concept of two interlocking volumes. The ground floor accommodates spacious lobby and reception areas for the offices in the tower and for the hotel in the base section, which were built according to a core-and-shell principle.
Underneath, in the four underground levels below the tower and the hotel, there is a multi-storey car park with a total of 153 parking spaces, as well as the hotel’s delivery zone. Some of the parking spaces are rented out to the tenants of the office space in the tower, while others are public and accessible to the hotel guests.
To enable the interior space to be used as efficiently and unrestrictedly as possible, the support structure is integrated into the facade layer. As a steel Vierendeel truss in the form of a building-sized square tube, it braces the whole building, carries the accumulated loads and also enables extensive projections on the lower floors.
The support system consists of prefabricated modular recurring elements. Each of these is made as a steel-concrete composite structure and meets the respective requirements regarding fire, assembly and static loading. This support system provides maximum flexibility for the rentable areas. The parking facility’s load-bearing structure, made of in-situ concrete, consists of flat slabs, columns and walls. The tower’s loads are transferred via these shear walls and distributed evenly over a large area in the floor slab.
Thin-film solar modules are integrated into the closed facade surfaces, and photovoltaic surfaces are installed on the roof surfaces. A borehole heat exchanger array provides the heat-pump system and cooling unit with geothermal energy.