Wood construction is currently experiencing a renaissance in Norway. Thanks to modern technology and advanced engineering, timber is becoming a fully-fledged alternative to steel and concrete, and the buildings being built are distinguished by their high standard and architectural quality. The Lumber 4 building in Kristiansand is good evidence of the development of this trend.
The total area of the building is 3106 square metres. It has six floors and functions mainly as an office building and, to a lesser extent, as a retail and service venue. The project was developed by Oslotre AS studio.
The structure of Lumber 4 is based on glulam elements formed by columns and beams. The ceilings were made as a combination of CLT and concrete, resulting in a slender system with long spans that also meets fire and acoustic requirements. Diagonal supports were introduced on the ground floor to facilitate the movement of cars around the building. The stability of the entire structure is also supported by a traffic core from the neighbouring phase of the development.
Between the third and fourth floors there is an atrium with a wooden staircase, which brings light and a sense of uninterrupted space into the interior. The use of wood in the room improves its thermal comfort, keeping it cosy in winter and cool in summer.
The façade is made of prefabricated curved pine elements coated with green paint. Straight eaves run above them, casting undulating shadows on the panels. Over time, the paint surface will age differently in sheltered and sunny areas, creating a facade that varies in appearance. The insulation was created from wood fibres and the exterior cladding from fire-protected pine.
The interiors of Lumber 4 are finished in a way that emphasises the character of the wood. The load-bearing structure remains visible, the walls are clad in spruce panels with white pigment, and wood wool acoustic panels have been used in the technical and meeting rooms. The open-plan installations have been painted a light beige, and large floor-to-ceiling windows let in natural light and open up views of the surroundings.
The entire project was completed in just 12 months and Lumber 4 has proven that modern timber buildings can compete with traditional steel and concrete structures – both in terms of completion time and technical standard. Already at the time of completion, 90 per cent of the space had been leased.
Architectural design, interior design and construction: Oslotre AS
Photographs: Kyrre Sundal, Christoffer Imislund/Oslotre
Read also: Interesting facts | Ecology | Norway | Wood | Office building | whiteMAD on Instagram
