Jaspers Eyers Architects

Quatuor Brussel

Brussels - Belgium - 2021

Where once stood the Baudouin building in Brussels, now shines Quatuor, a modern workplace with striking architecture. The building produces 30% of its own energy, has a rainwater recycling system and meets the Passive House standard. This, together with the 100% recyclable joinery by Reynaers Aluminium, has earned the project the BREEAM “Outstanding” label, a prestigious sustainable building certificate.

To leave the gloomy stateliness of the previous building behind, the architects chose for more playful, organic forms. Gilles Bollens from Jaspers-Eyers Architects explains: “Our idea for Quatuor was to create a building that would redefine the city at a key intersection. To do so, we opted for a soft architectural design, with mainly natural materials and big glass surfaces. All of this results in an exceptional project with an inviting character.”

Customised solutions to answer project challenges

If you consider the sheer size of a project like Quatuor, it is only natural that our Project Team was asked to offer their professional expertise. Quatuor’s building envelope consists of a custom-made element façade system, a unique solution tailored to the specific project requirements. “Reynaers Aluminium has various standard solutions which can be modified to the exact needs of a certain project. Together we came to a solution that tackled the main challenges of this unique façade” says Gilles Bollens.

ConceptWall 50 Façades, ConceptWall 86 Façades, CW 86 Standard Façades and CW 86-EF Façades - Quatuor Brussel located in Brussels, Belgium

The first and biggest challenge were the outer stone boxes and fins. These led to a higher weight and additional wind loads, which had to be structurally transferred through the façade. Even so, the boxes would also obstruct proper glass replacement in case of damage. To resolve this issue, Reynaers Aluminium created a special cassette system which can be disconnected from the inside of the building. This makes replacing glass panes a lot safer and a lot easier.

The curved façades, who maintain the soft architectural look, provide a second challenge. You notice Quatuor’s flowing design is much more complex than any straight building shape. ConceptWall 50 slim profiles create a bright contrast between the open base and closed upper storeys. The floors above include ConceptWall 65-EF and ConceptWall 86-EF solutions, featured in a tasteful white colour. It gives Quatuor its iconic modern look, while also offering optimal insulation.

Which brings us to the third challenge in the design phase: the required Ucw-value of 0.6 W/m²K. Reynaers Aluminium helped Quatuor meet this very severe U-value with high-performance aluminium profiles, intelligently designed gaskets and insulation strips, and best-in-class insulating materials.

Visualising ideas with virtual reality

With a project of Quatuor’s size, there are always some challenges to be expected. Nevertheless, we mitigated risks as much as possible by first creating a virtual mock-up in Avalon.

This immersive Virtual Reality tool allows architects to walk around in their design and immediately get a clear view of the impact of their choices on the appearance of the building. Decisions are tested immediately for practical feasibility, and technical problems become clear even to non-technicians. This results in huge time and budget savings.

In the case of Quatuor, stakeholders could compare colour choices, discuss aesthetic options, and secure the installation of the building cladding right in the Avalon VR room at Reynaers Campus. The original plan to lower the floors, which came with its technical dependencies, was also reviewed in Avalon.

“After construction had finished, we were very happy with the final result we achieved together with all partners.”

Gilles Bollens, Senior Project Architect

Extensive technical preparation

The Reynaers Aluminium Technology Centre, located at our HQ in Belgium, is one of the largest privately owned test centres for windows, doors, and façades in Europe. Here we test large façade systems for big projects from all over the world, such as Quatuor.

Quatuor’s façade has been thoroughly tested to meet all predefined requirements:

- for air tightness, it achieved the required pressure level of 600 Pa;
- for water tightness the limit was 900 Pa;
- the façade was successfully tested on wind resistance at about 1800 Pa;
- and it resists safety wind loads up to 2700 Pa.

Next to the Air-Wind-Water tests, we also checked the façade’s acoustic performance. And at a sound reduction of 43 dB, it perfectly met project specifications. As you can tell, nothing was left to chance with this project.