ICÔNE, a new office complex in Belval, Luxembourg, was meant to be the future of work. But the future got here quicker than expected. “We wanted it to be a cauldron of activity,” says Darren Haylock, partner at architect Foster + Partners.
“The idea was that a coworking organisation would look after the atrium, the ground floor and the meeting spaces, and another tenant would then populate the upper floors. But a French bank thought it would be perfect for its needs and ended up taking the whole building.”
It is a sign of how quickly ideas around shared space, wellbeing and informal working have become mainstream that, in just a few short years, ICÔNE evolved from being a fairly radical design proposition to the home of a major financial institution. “Five or ten years ago, developers were very focused on the net gross, or how much floor area they could get,” says Haylock. “But the client here wanted something unique. It’s an industrial location, out of the city centre, and it thought it would potentially be hard to attract tenants. So we thought, let’s be a bit braver.”
Then, of course, the pandemic hit, and ICÔNE became precisely what people wanted. The 18,800m2 building is filled with light and greenery – to the extent that, from certain angles, the exposed grid structure looks like an oversized garden trellis. This matrix of concrete elements is also a very visual demonstration of that fact that floor area is not the primary concern.
Throughout the atrium, beams trace the outline of where one might expect a floorplate to be, while columns rise unrestricted through all four levels of the building. The 24m-wide atrium, animated by planting, terraces and bridges, is the main space; the 16m office wings subordinate to it. “Attracting people back to the workplace, making that environment more inviting, has really come to the fore,” says Haylock. “There’s more focus on wellbeing and making it an exciting place to be.”
The BREEAM Excellent building’s 8.1m grid is expressed throughout, emphasising its supporting role as a stage for human interaction and activity. “The structure is the architecture,” says Haylock. “Where we don’t need material, we haven’t used it. When you see columns spanning four floors, it’s easy to understand, it’s intuitive.” This bare-bones approach is also key to establishing a sense of community, he adds. “The visual connectivity across different departments just helps that communication. Hopefully it becomes second nature.”
The columns were mainly cast in situ, but some were precast on site, as this helped with the buildability of the four-storey elements. To ensure continuity between finishes, the same steel formwork was used for both approaches, and the limestone aggregate was sourced from the same site for all visual concrete. Recessed joints separate the in-situ and precast elements, and also disguise day joints to create a crisp, controlled aesthetic.
The floor slabs have been cast on ply formwork with chevroned details that echo the recessed joints on the columns. These have been created by adding beads of painted ply to the formwork. Half-shell void formers were used in the central area of some slabs to reduce the embodied carbon and weight of the frame.
The slabs are also thermally activated, with chilled or heated water passing through a network of plastic pipes to help moderate the internal temperature. Additional heating is provided by a district energy system.
The facade highlights the legibility of the building too. The grid is reflected in 1.35m-deep, chamfered columns and beams, which are made from glass-reinforced concrete and supported from the in-situ frame. GRC was specified to make the deep elements easier to install, while still continuing the material finish from the atrium, merging interior and exterior.
The projecting elements control solar gain on the south, east and west facades. There was some anxiety that this might restrict natural light inside, but Haylock says the height and transparency of the grid draws daylight deep into the building, adding that it “bounces off” the concrete finishes.
The glazed facades also frame a dramatic view of a relic of Belval’s industrial past: a blackened and disused blast furnace. As the quarter adapts to a new life combining financial technology, higher education and retail, it is a reminder of how far and fast the human environment can change, and how the best buildings are able to embrace that.