Removing massive concrete panels was one of the most difficult steps of the project. Due to the tower’s complex geometry, curved both vertically and horizontally, all panels had different shapes and weighed up to five tons each. Tests were undertaken to better understand how it could be done, considering the sensitive positioning of the panels, some of which were situated above the sports centre while others sat above the stadium roof. The results of the tests were used to guide and support the contractor.
Replacing the concrete panels with a glass curtain wall while retaining the same curved form would have been very costly and, in the long run, would imply a significant risk in terms of potential problems with weather tightness of the facade. Consequently, the decision was made to eliminate the horizontal curve of the tower to simplify the new facade, while respecting the original architecture.
Our structural engineers designed slab extensions for each floor, which turned out to be quite a task due to the building’s complex angles and the different dimensions and form of each slab. A 3D BIM model was used to make calculations and design a secondary steel structure to support the curtain wall as well as for the construction of slab extensions. Once the design was completed, our team closely monitored the construction process.
Project deadlines were also quite stringent: our work on the project started in the spring of 2015 and finished in November 2017. The result, however, is impressive. The new facade complements and enhances the existing iconic architecture while letting loads of natural light inside the new office space. On the outside, depending on the time of the day and weather, the new facade either reflects the sky or exposes the tower’s complex structural elements.
The tower revitalization project will bring more than 1,000 employees to the area on a daily basis, potentially enhancing the vibrancy and the local economy of the neighbourhood.