Complex construction projects need time. Particularly when they involve a famous city location like Zürich′s Sechseläutenplatz. The planning and construction of the ″Opernhaus, Parkhaus Opéra und Sechseläutenplatz,″ project took 14 years and was finally completed and the square officially inaugurated in spring 2014. The first step, critical to the redevelopment of the square, was moving the parking lots from their above ground location in front of the opera house to the new underground parking garage, ″Parkhaus Opéra.″ Using design discipline, clarity, and a touch of color, Zürich architects Zach + Zünd – together with landscape architects VetschPartner and civil engineering firm Heyer Kaufmann – have given the square a suitable new structure. The large, open space with its striped Valser Quartzite stone surface is now a meeting point, a communal space, and an intensively public used area. In addition to the expanse of square, there are five tree islands with 35 tulip trees and 21 red oaks that provide passersby with shade and protection.
An impressive city square has emerged above the parking garage, and not only because of its view of Lake Zürich; the necessary access points to the square and opera house have been turned into small experience zones. The planners designed this space with lots of creativity, many years experience and using the high-performance architectural software, Allplan. They relied on Allplan as a dependable drawing tool from initial design through to project completion. Not an easy undertaking bearing in mind the complexity of the project. But using the building structure in Allplan with its drawing files and layers means that even huge amounts of data can be safely handled, plans clearly presented, and individual stories checked at any time.
Error-free planning across all phases enabled the planners to implement functional requirements as needed. It was rather external circumstances that were the cause of complications during construction of the parking garage: Reliable specialist knowledge was called for because of the high groundwater level owing to the proximity of the lake. To prevent upwelling, the diaphragm walls bordering the two-story parking space were concreted, the foundation bored piles inserted, and the concrete cover of the parking garage formed. Only then did excavation begin.The structural works ended with the concreting of the floor slab and the suspended ceiling. The opera house on its 1,833 oak piles was at particular risk because of the difficult subsurface, and therefore was kept under constant observation.
Spectacular finds of Neolithic pile dwellings also halted construction for nine months. Some 20,000 finds were recovered, some of which can be viewed in the ″Archaeological Window″ – housed in an information and exhibition space, also designed by Zach + Zünd – in the lakeside staircase area.
″With Allplan Architecture, we can not only plan complex construction projects in great detail, but also check them with great accuracy.″
Stephan Rist, Zach + Zünd Architects
A pavilion above ground invites passersby to visit the excavation findings. Its city-side counterpart has a café inside and is adjacent to an emergency exit for the opera house disguised as a vitrine. This is the only other indication at ground level of the parking garage. Both pavilions are covered in filigree lasered metal panels with a grill effect. The decoration was developed by textile designer Janine Graf and is not a random choice either. It is based on the stylised basic design of Lake Zürich. Visually, the grills unify the different functions of the pavilions: staircases, elevators, café, storage space, and toilets. They also serve as fall protection – and guarantee smoke extraction as specified by the local fire and rescue authorities in the event of a fire. This meant that the architects were able to dispense with the usual safety doors and gates. Daylight can penetrate unhindered to the lower parking level. In the sunlight, the grill ornamentation creates an atmospheric light and shade effect all the way down. This skillful solution allows the underground parking garage to become part of the city space while creating a friendly and pleasant atmosphere. If you do not want to leave through the pavilions, you can also exit the parking garage through an underground space that connects with the opera house. This space, with its extensive projection and a background of copper-colored curtains along the wall, forms an impressive prelude to the opera. The current opera and ballet productions are shown here in large format in original sound and picture. The glass elevator takes you up to the new foyer. You couldn′t wish for a more stylish start to a visit to the opera.
Zach + Zünd architects was established in 1988 by Gundula Zach and Michel Zünd and has operated as a GmbH registered company since 2006. Zach + Zünd has 14 employees. The company′s range of services includes a wide variety of construction tasks across all phases. Zach + Zünd specialises in town planning and consultancy, public buildings, and residential and commercial buildings.