Treemont: new six-storey wooden office building in the European district

The building permit has not yet been received, but that seems to be just a formality. Over the course of next year, a wooden office building will be built on Montoyerstraat in the European district in Brussels, without any corpses out of the closet. The building, called Treemont, will have six floors with generous ceiling heights and replaces a concrete office building on the same site. Architects on duty are ARCChi2000 (architectural design) and Sweco (structural design), who designed the project on behalf of Nextensa. Both firms previously worked together on the design of Monteco, the tallest wooden office building in our capital on the same street. With a height of 25 meters, Treemont is not far behind.

The existing concrete office building is disappearing because it has a particularly poor EPB score, no longer meets the acoustic requirements for offices and, with a rather low ceiling height, can no longer offer the comfort that you can expect in office buildings today. The underground parking garage will be retained. On top of this will be a new wooden office building of 25 meters high with six floors with a greater ceiling height and more comfortable workplaces. Beneens will realize the project.

The parties involved are confident that the building permit will be issued quickly and the demolition of the existing building can begin by the end of the year. The name of the project, Treemont, refers to the trees in the backyard – which the building will also have – which will be visible from the entrance, and to the street in which the building will be located.

This is what Treemont will look like – Image © Sweco

Wood, wood and more wood

However, the tree in Treemont could also simply refer to the large amount of wood that disappears into the building. It will have a structure of beams and columns of laminated timber, approximately 110 m³ in total, and CLT floors, which required approximately 560 m³ of CLT plates. Only in some places are steel beams used to make the large ceiling heights practically possible. All wood used has a PEFC label. The facades are finished with wooden cassettes.

Bassim El Jazouli, project leader on behalf of Sweco, explains the choice of wood. “Wood is a sustainable building material with much lower carbon emissions, because it captures CO2 even when it stops growing. In addition, it has good insulation properties and a weight-to-strength ratio that is better than that of concrete. Because the material is so light, the existing concrete foundation can be reused without having to reinforce it. The wood we use is flammable, but, unlike steel, has a high fire resistance because it has been carbonized ensures that the mechanical properties in the cross-section of the wood are retained much longer in the event of a fire. In addition, various studies show that a wooden building when the wood remains visible, which will be the case in Treemont, is experienced by users as warmer and more comfortable. Finally, you can also build faster with wood than with concrete. The beams and all other structural elements can be prefabricated in dry conditions, resulting in a much shorter construction phase.”

A 3D image of the building.

BREEAM Excellent certification

A wooden building with a height like that of Treemont, 25 meters, is rather the exception. This makes the office building a reference project for Sweco, says Bassim El Jazouli. “Just as the Monteco office building (see this article, ed.) in the same street, with eight floors slightly higher, is also a reference project for us, he says. “But also thanks to the planned BREEAM Excellent certification, the building will be considered a business card may be considered.”

Sweco does not yet know whether Treemont can be completely dismantled. Bassim El Jazouli: “But all beams will probably be clamped between or attached to the columns with steel dowels and will therefore be easy to dismantle from the columns. The CLT plates will then be screwed back to the beams.”

The inside of the building will be very similar to that of the nearby Monteco, pictured here.

“Timber construction is the future”

The project leader also indicates that Sweco wants to use wood much more often in its projects in the future. “Monteco and soon also Treemont are success stories that show that you can actually design projects of any scale in wood. We should not always choose the easiest way and go for steel and concrete. Wood construction is essential if we want to move towards a carbon-neutral construction sector and built environment to evolve,” he concludes.