Europaallee urban quarter Zurich central railway station

The building erected on construction site B, which was designed by Zurich-based architectural office Stücheli, stands at the entrance to the new Europaallee quarter along with the listed Sihlpost building. Constructed on a narrow trapezoidal parcel of land between the railway tracks and Europaplatz, the new building is made up of a two-story base and a seven-story timber-frame construction.

Even the construction pit proved a genuine challenge for PORR. Due to the density of the overall project, it was not possible to plan and implement the construction pits separately for the individual sites and lots. Consequently, the construction pits for site B, site D and the “Europaallee stairway” and “Bike park” lots had to be planned and implemented together. The fact that some parts of the new building were to be constructed above and beneath the railway station’s platforms proved a complication. Another challenge lay in the need to reroute a media duct responsible for the station’s utility supply and waste disposal systems. The station’s district heating supply also had to be maintained throughout the construction period.

The construction pit was secured using a combination of (soldier-pile) retaining walls and sheet-pile walls before being back-anchored with numerous rows of anchors. The accumulated water was captured in pump shafts, subjected to an automatic quality inspection and then pumped into the Sihl River.

Made from black Swedish granite, the banding that surrounds the upper floors emphasises the building’s numerous storeys. Between the bands are supports clad in electro-polished stainless steel and windows with eucalyptus wood frames. The windows are shaded by external blinds with micro-louvre blades.

The entire façade is a curtain wall system. It transfers its loads into the front ends of the ceilings on each floor. The banding areas have been realised as a ventilated façade construction. The façade has been cladded in perforated stone slabs made from black Swedish granite.

The entire façades of both towers, like the building on site B, are curtain wall systems that transfer their loads into the front ends of the ceilings on each floor. However, these façades feature a much higher proportion of glass than the building on site B. The non-glazed areas of the façade have been reduced to the structurally necessary cladding for the framework construction and the ceiling layouts.

This Activ-Air-Plus façade comprises double-leaf, closed aluminium-profile window elements with freely adjustable curtains in the space between the panes. The remaining areas of the façade were covered with prefabricated curtain-wall frames made from both smoothed and acidified white concrete. The concrete frames, which have maximum dimensions of 2.5m x 4.5m, had to be “slid over” the substructure and fixed to the skeleton structure with stainless-steel anchors once the window elements had been installed. All white-concrete surfaces have been rendered hydrophobic and oleophobic, thereby protecting them against moisture and oil.

The materials used in the façade have also been used in the building’s interior. Glass brick elements have been integrated, particularly in wet rooms. In addition, the stone used in the façade has been used again as a floor covering. The architects also integrated clay elements in this project, which has been used as ceiling plaster, with a rather more durable fine lime plaster applied to the walls. The clay acts as a buffer to regulate air humidity in the apartments and ensures a pleasant indoor climate.

In contrast to sites B and D, on site F PORR also completed the internal construction and installed interior fittings. This work involved apartments that had been planned in detail by the architects. In fact, they even designed some elements of the interior fittings themselves, and commissioned small-series production after consulting with the building owners. The commissioned elements include a suspended metal kitchen element that serves as a wall cupboard, a suspended mirror cabinet in the wet rooms, and a base cabinet to fit under the washbasins. Glass-brick lamps, specially developed for this project, have been installed in the entrance areas to the residential towers and in the lobbies outside the lifts on each floor.