The design approach used for the Mjösa Tower is firmly rooted in the Norwegian tradition of using wood in architecture to stand the test of time.
“We want to inspire others to build the same way,” says Øystein Elgsaas, architect and partner at Voll Arkitekter, the agency that designed the Mjösa Tower.
To design a tall building using wood was a positive challenge for Elgsaas. The load-bearing structure is similar to conventional buildings, but the dimensions of the elements are much larger than usual: The wooden columns were 60 × 60 centimetres on average, and the largest ones used in the corners were almost 60 × 150 centimetres.
The narrow, yet wide shape of the Mjösa Tower is ideal for hotel rooms.
“We had to find a narrow plan layout, which both provides room for different kinds of spaces and ensures the columns are not too dominant in the interior, but we achieved it,” says Elgsaas. The building won the prize for best mixed architecture at the 2018 New York Design Awards.
Both the “skeleton” and “skin” (i.e. the structure and facade of the Mjösa Tower are made of wood. The structure consists of glulam columns, beams and diagonal members, which are well-suited to high-rise buildings as the large cross-sections can meet fire safety requirements. The first ten floors, with offices and hotel facilities, are made of prefabricated wooden elements – and that is where Kerto LVL Q-panels from Metsä Wood provide stiffness. Kerto LVL is combined with glulam.
The decks on the upper floors, with apartments, are made of concrete. This is due to the fact that the amount of swaying increases the higher you get in a building built of wood or concrete. The weight of the concrete makes the swaying slower and not as noticeable. The shafts for the elevators and staircases were made of CLT.
Kerto LVL Q-panels were easy to process as a component of the prefabricated wooden elements at Moelven Limtre’s factory. Some of the Q-panels were pre-cut and sanded beforehand at one our collaborator’s factories.
“Kerto LVL is a lightweight and very straight material; thus, it guaranteed production without any delays. The quality of the product is very good,” says Rune Abrahamsen, CEO at Moelven Limtre. Cross-laminated Kerto LVL also has a great strength-to-weight ratio.
Lightness was a benefit in the assembly phase as well. As all elements were prefabricated and light to handle, the structure grew by almost one floor every week.
