STACK: quirky and sophisticated

With a height of 70 meters, STACK is a proud presence at the head of the Müllerpier in Rotterdam. However, it is not only the height that draws attention. The sculptural shape and unusual masonry dressings of the facade also make STACK stand out. "An expression that suits the special environment," says Jeroen van Iperen, operational director LT Afbouw.

While on the New Maas the ships sailed by, a whole new residential district was rising on the Müllerpier, with STACK as its spectacular finale. Van Iperen knows better than anyone how special this location is. He says, "While working you experience the whole of Rotterdam, from the activities on the water and in the harbors to the view of the Euromast. It is this connection with the city that is also reflected in the facade. Groosman Architects has thought very carefully about the masonry dressings. Such as a block bond with a three-centimeter wide joint in the plinth, while in the third block Sto mineral façade strips and EcoShapes are processed in polymetric bond with joints of twelve millimeters." For the second and fourth blocks, the architect opted for butt jointless. "This was done very deliberately, to make the residential tower look narrower sometimes and wider on other floors."

28 different sizes

Working with different dressings, in a project of this size, requires a lot from the processor. "This is a facade of about 4,500 m2 with 28 different sizes of facade strips," Van Iperen explains. "The fact that we brought it to a successful conclusion is due to a thorough preparation involving both, Sto, Groosman Architects, VORM Bouw, the aesthetics committee and us. Life-size mock-ups were made for all the blocks. Moreover, the architect meticulously drew out the entire pattern for us." That elaboration, the preparation, the delivery of the day's production and a back-up stock on site ensured that the processing process went smoothly. "In the beginning it was sometimes puzzling - because wide joints require meticulous work - but soon our people got the hang of it."

Light construction offers maximum freedom

It is also special that exterior wall insulation was chosen at STACK. "It is a concrete support structure filled in with timber frame construction and exterior wall insulation. A construction method that is both light and flexible and that allows for customization. But this windy location also required deep anchoring of the façade panels and additional 'plug points.'" Another big advantage is the combination of HSB, exterior wall insulation and mineral wall strips. "The gable strips are light, but more importantly in this case: you can vary them," he says. The architect made maximum use of that freedom by designing masonry patterns with a twist. A design that falls and stands on the accuracy of its execution. "But, then there is also an end result that may be seen," says Van Iperen. A facade that makes you want to look at it a second time, and one that honors the rich history of the Kröller-Müller family (yes, of the Kröller-Müller Museum) through its nuances and idiosyncrasy.