The new headquarters, with five underground and seven above-ground floors, will provide working space for around 4,500 employees. That is a good 70% more than today, on an almost identical gross surface area of 103,500 m2. The building will include high quality equipment and the latest technologies, including solar panels on the roof and seasonal thermal energy storage (STES), optimizing environmental performance and enhancing staff comfort. Drawing on its previous experience, BESIX is contributing its expertise to achieve BREEAM 'Excellent' and 'Passive House' sustainability certification for the building.