Ponte dei Congressi
Zurich in the 1950s: Under the slogan “Freie Limmat,” activists proposed a referendum which would later have severe impacts on the urban development of the city centre. The goal of the program behind this catchphrase can be quite literally described as the freeing of the Limmat River of any buildings crossing or standing in close proximity to it. No attention was paid to the individual structures affected, nor to the urban qualities they produced. Instead, the buildings were supposed to make way for infrastructural projects dedicated to the prosperous uprising of the automobile. On the 25th of February, 1951, the motion was accepted with a majority of 57 percent.
Over the course of the following decades, after most of the buildings had already been demolished and the streets widened, the intervention was assailed. Aside from the loss of historical artefacts such as the “Fleischhalle” (in English, “the meat hall”—a stunning 19th-century butcher’s market). the new open spaces were too undefined for any use other than being occupied by cars.
The Papierwerdareal—once an island on the Limmat—represents this conflict of interest and the indecisive, retrospective attitude towards the “Freie Limmat” movement. Several architectural competitions have been held to try and determine how to proceed with the site. Currently, a provisional building erected in the 1960s still covers the plot and exemplifies the dispute. Over the following years, much has been discussed and written about the destructive impact of freeing the Limmat; nevertheless, the city seems paralyzed and unable tackle this unique urban problem.
Placed right in the river, my proposed project is seen as a rejection of the “Freie Limmat” movement. As a new urban interface, the proposed building replaces the existing bridge between the main station on its west and the central square on its east. Spanning from one river bank to the other, the building enforces the connection between the two major pedestrian streets, Niederdorf and Bahnhofstrasse. An integral element of the project is the loggia—an array of porticoes on two stories—enclosing the building on all sides and defining a public threshold. Its generous dimensions (9 meters high and 6 meters wide) creates a covered urban space which serves not only as a “passarelle,” but also a place to linger in proximity to the river. On the ground floor, the building incorporates the existing tramways and create an arcade punching right through its total length. Cafés, shops and galleries open up on two sides, facing towards the loggia and the arcade and creating a porous public structure. Additionally, the existing parking lot is transformed into an exhibition space below river level, with the entrance marked by a sculptural staircase.
A congress center, which is used only 40 days per year does not contribute sufficiently to the urbanity needed in such an important, central location. Therefore, the design is deliberately not derived from its programmatic necessities, but rather from its urban potential (maintaining the adaptability of different forms of use). Six stair cores provide access to all stories of the building, leading from the entrance halls on the ground floor to the public foyer on the first floor, and then up to the great hall on the second floor. In between the ground and first floors, a Mezzanine level provides additional rooms for the congress centre. In the foyers, public and private programs overlap and connect the building with the city. The generic structure permits manifold uses, allowing several events to happen simultaneously.
The monumental image of the building is constructed through the joining and adding of repeating modules. Placed on a foundation of concrete pillars and a concrete plate, timber panels is joined in a rigid grid to form the whole. The bridge for vehicle transportation is decoupled from the rest of the building to avoid vibrations.
The seemingly ephemeral and temporal quality of timber construction and its haptic qualities—a reference to historic covered bridges—adds a human scale to the building. Cross-laminated timber panels with layers of different types of wood, depending on function, creates a resistant and durable material. The structurally-relevant plates are then covered in protective paint and joined to create different modules. The directness of the construction is perceptible throughout the building. The beam in the great hall works as an underspanned girder with panels for bracing and compression forces. The lower tensile element is directly attached to the exterior wall and prevents the beam from buckling.
Zurich, a city with an exceptional quality of life that is directly connected to its abundance of clean and fresh water, still has great potential to further incorporate the river into the city. The decision to demolish structures in or by the Limmat only reduced the potential of the river to contribute to a vibrant urban society. With this project, I want to propose an alternative—a way to make the Limmat an integral part of the city rather than simply a background for postcards and photographs.
Location: Zürich, Switzerland
University: Die Eidgenössische Technische Hochschule Zürich
Semester: Master Project
Teaching: Adam Caruso - Florian Summa - Claudio Schneider