Facades high-end office building aligned with surroundings

Gem on Apollolaan

On the corner of one of Amsterdam's most prominent green avenues, the Apollolaan, a high-end office building has risen. The building has a different facade construction on three sides that is completely attuned to its surroundings. And in doing so, the boundaries were explicitly sought out, as evidenced by the deep fins over the entire building height, with no connecting horizontal element. Leave that to the experts at Vorsselmans who were responsible for the complete building structure of this gem that is bursting with technical highlights.

The office building is in a very specific location in Amsterdam, begins Johan Hendrix, project manager at Vorsselmans. "OMA Architects tailored the design to the surroundings. So the design is characterized by three very different facade types. The north facade, facing the park, has a very flat appearance with as little relief as possible, executed in a structurally bonded facade by Schüco. The rear facade connects to a neighborhood with a lot of architecture according to the Amsterdam School. This explains the specific detailing with bishop's caps and brickwork. Finally, the east and west facades facing Apollolaan are characterized by interlocking glass volumes that resemble a jigsaw puzzle. That image is reinforced by the vertical fins."

Complex nodes

The stacking of volumes in combination with the deep fins on the east and west façades did require some engineering attention, according to Johan. "If we just look at the cubes sticking together, that gives us a particularly large number of complex knots that we solved each time in the corners of the facade and are therefore not visible as such. That was quite a challenge," Johan knows. "In addition, provision had to be made in the facade for the vertical strips in the form of deep fins. For this, cruciform support structures were developed and incorporated into the facade, which continue into the fin construction. It was performed as a custom extrusion, a very special process too, because of the finding depth of no less than 435 mm."

Wind load and thermal expansion

Speaking of the fins, they cover the entire building height without the addition of a horizontal connecting element. "And that's even though there is quite a bit of wind load on the facade," Johan adds.    

"If you look purely at the fin construction as an outsider, it seems impossible at first. Together we managed to make it possible. You can imagine that the necessary research and testing was done to make the fins resistant to wind load and thermal expansion. The latter is also a 'little thing' with this kind of extreme dimensions. The fin must be able to expand and contract unhindered. We solved this by creating a sliding connection with a special insert component. That 'junction' was also extensively tested, even in a mock-up. Every detail in the design has been thoroughly considered."

Window frames as miniature curtain wall

The fins on the east and west facade not only provide a great contrast to the smooth north facade, they also provide some shade. "The east and west facades can experience quite a bit of annoyance from incident sunlight, with these fins as passive shading, this is largely prevented," Johan explains. "Finally, the facade at the rear is executed in 'squares' of masonry to match the scale of the residential area. Basically, the Schüco window frames are actually mini-walls to achieve the same look for the user aesthetically from the inside. There again, the crux lies in the nodes, the point where one curtain wall merges into another, with no room for a masonry support or other features. Again, an engineering feat. That combined with high-end glazing with a silkscreen pattern broadly reflects the complexity of this project."

The plinth is executed in a continuous curtain wall. "To scale down the superstructure and bring back the human scale in the plinth, a transition zone was created with a kind of ladder profile executed with aluminum tubular profiles." All in all, Johan looks back on a technically complex but very pleasant project. "The great thing about OMA Architects, who are after all mainly known for their sensational creations, is that they implemented that same high quality down to the detail level on this relatively modest project. So that once again a gem is created. This is also how we as Vorsselmans are in the game. We are capable of pushing the boundaries and making the almost impossible possible. This office building is a striking example of that."