Circular and sustainable ambitions
Maximum efforts were initially made to preserve the existing infrastructure: the old archive cellar was transformed into a bicycle shed and made accessible from the street side, the 3 existing rear building volumes were stripped and renovated in their entirety according to BEN principles. Despite their robust structure, the existing main volumes were not compatible with contemporary comfort requirements. They were demolished and replaced by a new volume in wood massif construction. By building with wood massif construction, the carbon footprint of the new building is significantly reduced, a very conscious choice by the client and the design team.
By opening up the rear building volumes and connecting them in a clear way to this new volume, the desired building programme could be fully realised. The building on Koning Albertlaan could be disconnected and 2 open, green gardens were created in the inner area, seamlessly connecting to the cafeteria and meeting rooms.
In addition to the reuse and renovation of the existing volumes, a complete inventory of the existing loose and fixed infrastructure was already made in the demolition phase, together with Labeur vzw, as well as of the joinery and specific (dismountable) building materials, among other things. Items such as insulation, interior joinery and finishing materials could thus be given a second life via an alternative circuit. Some specific elements (including the existing cabinet doors, kitchen appliances, reels and acoustic sliding walls) could be reused in the new building.
A flexible and readable structure
At ground level, the new main volume will have a glass, inward-sloping volume and a wide subway, creating a strong link between the inner area and the street. In this way, access to the building, the inner area and underground bicycle storage are opened up in one move. The glass plinth forms a transparent and light plinth, thus emphasising the austere wooden volume. The entire ground floor is occupied by the cafeteria with informal work and meeting areas on the street façade, and serving functions and meeting rooms in the rear building. The upper floors include classrooms, offices and meeting rooms for ACV-CSC-Metea.
The main building stands on a new concrete basement - where all the technology and necessary storerooms were housed - and is hemmed in on its southern flank by a concrete staircase and lift core. The 3 upper floors, mainly containing offices and meeting rooms, are built entirely of solid wood. By combining slender solid wood floor slabs and beams, the techniques (lighting and climate ceiling) can be incorporated into the grid of the ceiling. The result is a balanced and warm interior with lots of visible structural wood, combined with light infills for the climate ceiling, raised floors and walls. The open structure allows the various office plateaus to be completely dismantled and freely reconfigured from the inside in the future.
A wooden building with a wooden facade
In collaboration with Bureau Bouwtechniek, the project's façade design was optimised and refined. Through dynamic simulations and material research, a balanced balance was achieved between various factors, including daylighting, shading and thermal comfort. The position, size and orientation of the wooden louvres were carefully determined to meet fire reaction class requirements and to achieve optimal modulation of daylight versus cooling demand.
The vertical slats were strategically placed to keep direct sunlight out, while the horizontal slats reflected diffused daylight deep into the offices. By inclining the louvres in different directions, peaks in daylighting could be smoothed during the day. The use of thermally treated FSC spruce for the slats not only provided passive shading, but also gave the building a characterful look and strong rhythm. This sophisticated approach resulted in a façade that is not only functional and energy-efficient, but also aesthetically strong and in dialogue with its surroundings.
