Iconic and complex facade structures for City Campus

Landmark on Oosterdok Island

A 3D articulated construction, sloping and faceted facades, huge glass surfaces, minimalist sliding doors and high wind and water tightness requirements, typify the iconic City Campus at the head of Oosterdokseiland in Amsterdam. City Campus unites a large-scale multifunctional office building of 95,000 m2 for Booking.com with 41 high-end apartments by Ode Appartments in the adjacent residential building. The impressive (facade) architecture forced Scheldebouw and Solarlux to create extremely complex and project-specific solutions.

City Campus is a design by UNStudio. Creating a work environment that is socially, physically and mentally healthy for Booking.com employees was a key design goal from the beginning, according to the architect. Throughout the building, the architecture encourages employees to move. Special attention was paid to creating as much natural light as possible throughout the office building. In turn, the design of the residential building refers to the old harbor buildings in Amsterdam. The positioning on the lot was optimized for the best views of the river and the city. The view is further enhanced by the use of room-high sliding doors up to 6 meters wide. With a total of 41 residences, the building houses six different apartment types, from studios to two-story apartments ranging from 67 m2 to 300 m2. 

Atrium roofs

The impressive facade of the office building and apartments comes from Scheldebouw, part of the Permasteelisa Group. "We engineered, produced and assembled a total of about 15,000 m2 of façade structures, consisting of element façades, various types of post-and-beam façades, structural glass façades and the structure for the three atrium roofs," says Scheldebouw project manager Joost Schins. "To start with the latter, two of the three atrium roofs are attached to the contractor's primary steel structure via a set-up structure we developed. They are more or less two identical glass roofs in terms of construction. The third atrium roof was built on a secondary steel structure provided by our subcontractor and steel supplier CSM, on which we built the auxiliary structure for both the glass roof and the connection to the façade."

Style and control facades

For the facade of the office building, Scheldebouw developed six subsystems, three post and control facades based on Reynaers profiles for the lower part and three types of element facades above. "The style and control facade on the ground and second floor levels is made of aluminum with structural glazing for maximum transparency," explains Joost. "The stile and control facade on the south side of the building was by far the most complex in its elaboration. On the one hand because this facade is anchored directly to the primary steel structure and on the other hand because of the desire to keep the dimensions of the aluminum profiles as minimal as possible, even in depth. For this, we developed and pressed a specific aluminum system, which was tested in a mock-up to assess whether it functions as conceived. We are dealing here with quite a difference in tolerances; in primary steel you often talk about centimeters, while in facade construction we only engineer to a few millimeters. We have to be able to accommodate that difference. And that worked out well." Finally, the third type of post-and-beam façade was also pressed within Scheldebouw's supply chain, particularly to accommodate the large spans.

Element facades

For the element façade, Scheldebouw also developed a project-specific profile set, which serves as the basis for three different types of elements. "About 50% of the element façade consists of relatively standard flat elements," says Joost. "Some 30% of the elements have a diagonal column in the glass surface, a kind of donkey ear. That variation creates a playful effect in the facade appearance. Finally, the last 20% consists of special 3D-formed elements, and these are located particularly on the east side, where the facade folds inward, as it were. The elements are also mounted at an incline on the primary steel. That too presented the same challenges in tolerances, bending, etc. But Scheldebouw also knows how to deal with that. We think along with the architect at a high level and then translate this into a feasible and efficient facade system. Clients can entrust the entire building envelope to us, whereby we also take care of the entire coordination, project management, supply chain and assembly. We take care of the total picture and that makes us very strong."

Minimalist sliding doors

For the facade of the residential building, Ode Appartments contacted Solarlux at an early stage. "Initially, the idea was to equip the glass facades of the apartments with a folding wall, but because of the intended maximum transparency, we proposed an alternative with our minimalist cero III sliding doors equipped with triple glazing. These not only offer impressive transparency, but also meet the high wind and watertightness requirements set," says Andre Jansen of Solarlux. "Because we were switching systems, it was our job to work with Sorba to engineer the proper detailing and construction coordination. At Solarlux, we think that's the best thing in the world: fleshing out the facade sealing from scratch based on the set principles. We invested heavily in the details, in making a mock-up at our factory in Melle, Germany, and in testing the facades. And all that in the preliminary phase, even before we had the order."

Transparent French balcony

Solarlux's cero III system is a highly insulated, room-high sliding window with styles only 34 mm in view. In accordance with the Building Code, the facades must have a fall-through protection, a French balcony, because the sashes can be opened. "However, a standard French balcony detracts from the intended maximum transparency," André acknowledges. "We therefore went back to the drawing board and developed a special profiling with our R&D department in Germany in which a fully transparent fall-through protection is integrated into the cero façade. The whole thing was extensively tested using, among other things, a pearl bag pendulum test on the mock-up in our factory, under the watchful eye of an external agency, of course. We also tested the facades for wind and water tightness, including all structural connections with the structural frames and sheet metal. As if that wasn't enough, tests were also eventually performed on site."

Years of experience with our products, including in high-rise projects where sometimes the most extreme wind and watertightness requirements are demanded, enable us to tackle these kinds of complex challenges, André says. "It is also very nice that we have an R&D team from the factory behind us. Technically, the spans and deflections of the concrete structure are such that we have built in the possibility of adjusting the facades in the future. Without compromising wind and water tightness." In total, Solarlux installed 190 cero III facades consisting of approximately 350 sashes. "We were able to bring the project to fruition in excellent cooperation with Sorba. As one of the most prestigious buildings in the Netherlands, another great reference for us."