Scalloped sections of green timber clad the facade of Lumber 4, Southern Norway’s first and, to date, largest timber hybrid building designed and constructed to “demonstrate the capabilities of timber construction.”
Designed by Oslotre, one of Norway’s top timber architecture and engineering specialists, the building uses a glulam, cross-laminated timber and concrete building system that is now economically competitive with conventional steel and concrete buildings.
As reported by World Architecture, Lumber 4 was constructed in a near-record time, aligned with the EU’s new taxonomy and tapped into prefabrication to deliver a building that cut embodied carbon by 53% relative to conventional construction.
Connecting to the lift and stair core, the building’s recessed ground floor curves follow the adjacent road, while the upper floors project outwards and are supported by large wooden beams.
According to the studio, “The floors use a composite structure of CLT and concrete, creating a slim and efficient floor system that spans long distances while also addressing fire and acoustic requirements.”
“Diagonals on the ground floor facilitate vehicular access around the building, while the existing communication core from the adjacent building phases contributes to lateral stability and access to the office floors.”
In addition to the flooring system, glulam was used extensively in all the columns and beams, whilst CLT and concrete were used in tandem to build the decks. Inside the building, an internal staircase made from CLT connects the third and fourth storeys inside the six-storey building.
On the exterior, glazed openings and curved timber panels create a checkerboard pattern across the office storeys, while the curved ground floor features full-height glazing framed with green-clad timbers.
The studio said, “The eaves above the curved elements are straight, creating a curved shadow on the panel.” Before adding that, “over time, the paint under the shadow will weather, leading to a changing facade with lighter and darker curved sections.”
Internally, the building’s wooden structure has been left visible, with white-pigmented spruce panels and exposed wood-wool acoustic panels cladding the walls and ceilings. Ducting was also left exposed throughout and painted pale beige to better match the wooden surfaces.
- To learn more about Norwegian timber construction, click Wood Central’s Special Feature on Norway and Sweden, filed by the WoodSolutions and TDA delegation before last year’s World Conference on Timber Engineering in Oslo, Norway.