“The Lighthouse” in Aarhus, Denmark’s tallest residential building with an unusual roof shape.
The artificially created district near the centre of the Danish port city Aarhus offers spacious new living space. The latest construction project, “The Lighthouse,” contributes significantly to this by adding 400 new apartments to the housing market. As the name promises, the building rises majestically like a lighthouse on the southeastern shore of the harbour area, and it is also Denmark’s tallest residential building.
Small roof, extensive planning effort, and an additional floor.
The building captivates with its unique architecture, especially the organic and geometric shapes of the roof, facades, and balconies. Particularly striking is the parallelogram footprint of the building, rounded on two opposite sides. The realization of this design was a challenge that Robert Thiebes of Kalzip mastered with confidence, using specialized software and on-site data collection. Particularly innovative are the diagonal standing seam profiles of the roof terrace, which allow for efficient rainwater drainage while also serving as a stylistic highlight. During the structural calculations, it was discovered that an additional floor was possible, perfectly suited for creating a sophisticated gastronomy and viewpoint for visitors at 142 meters above ground.
Installing accurate to the centimetre
During the processing on the construction site, the team of the executing company AE Stålmontage a/s started at the highest point of the roof and initially moved on one half of the roof towards the roof terrace. The assembly proceeded as usual: The profiled panels were placed on top of each other at the seam and flanged with a flanging machine.
The installation of the complex, three-dimensionally curved Kalzip XT sheets with a corresponding angle of inclination proved to be particularly tricky. Despite the flexible substructure, which offered a little room for manoeuvre during installation, as well as the clearly laid out construction plans, construction was briefly halted, as Robert Thiebes reports: “In this project, there was only a few centimetres of displacement space between the profiled sheets, which decided whether the next sheet would fit in or wedge in. In order to find the best possible solution to this problem, we travelled to the construction site, were able to quickly locate the error and instructed the employees accordingly.”
Roll-formed and twisted
Innovative techniques were necessary to implement the curved transition from the roof to the facade. Each individual standing seam profile of the building was numbered and prefabricated in advance, then specifically bent and twisted according to its designated location. As always, this required precise millimetre work, leaving no room for errors. The installation of the complex, 3D curved KALZIP XT panels with a certain angle of inclination posed the biggest challenge, as there was only a few centimetres of leeway for installation.
A wind-resistant challenge
The “Lighthouse” presented special challenges during planning and construction, especially due to limited storage space because of the surrounding buildings and proximity to the water. Consequently, all materials were stored in the neighbouring port docks. Transporting the standing seam profiles from Koblenz to Aarhus was a logistical masterpiece. To protect the different angles of inclination of the profile panels, they had to be stacked on pallets with special spacers. A crane transported these pallets to the roof. Due to the height and resulting wind suction, the unused standing seam profiles had to be secured with tension straps.
The finishing touch
With the completion of the roof, the exterior shell of the impressive “Lighthouse” building was finalized. The 480m² XT profiles from Kalzip, not visible to visitors, incorporate a sophisticated recess for a maintenance crane. “Despite the relatively small area, the ‘Lighthouse’ roof stands out for its unique and demanding shape, making it a complex and time-consuming challenge,” says Robert Thiebes.
Considered with care. KALZIP.
Yannick de Beauregard
August-Horch-Str. 20 – 22