The whole Verksbyen area in Norway presents the future of sustainable living – and Metsä Wood’s Kerto® LVL (laminated veneer lumber) is part of the story. Prefabricated elements incorporating LVL are used in the construction of a block of ecological apartment buildings.

Fredrikstad’s new green neighbourhood, Verksbyen, will become home for 5,000 people within the next 10 years. It aims to be Norway’s most innovative housing project. In the long run, the developer, Arca Nova Bolig, has ambitious plans to change the housing market in the same way as Tesla has transformed the car industry. It is a lot said, but they strongly believe in growing demand for sustainable building, which is the backbone of Arca Nova’s Future Living concept.

“We have managed to reduce CO₂ emissions in a variety of ways. The houses are built with timber elements according to the passive house standard, and electricity is produced with solar energy and heating with solar thermal energy. Smart house technology with voice control adds an extra touch to all of this. As a result, the inhabitants will not only live sustainably, but enjoy reduced living costs too,” says Ruben D. Hansen, CEO of Arca Nova Bolig, part of the Arca Nova Group.

Metsä Wood is an important partner in the project as the constructor Arca Nova Bolig uses Kerto LVL products. The constructor also had help from Metsä Wood for developing its own construction concept to build tall timber apartment buildings. Arca Nova Bolig is building a total of five five-storey apartment buildings incorporating Kerto LVL Q-panels and S-beams in the wall and floor elements. The buildings are situated in the Capjon Park area in Verksbyen, close to a beautiful lake called Sorgenfridammen.

Fast, light and green construction

It is easy to understand why Arca Nova Bolig and Metsä Wood make such great partners. Hansen highlights the lightness and load bearing capacity of the Kerto LVL products. Building with sustainably sourced wood is also an environmentally friendly and sustainable way to build now and in the future.

“Constructing with prefabricated elements using Kerto® LVL products, we reduce both building time and CO₂ emissions quite substantially compared to the traditional way of building with steel and concrete. Also, the dimensional accuracy of Kerto LVL is a benefit, as the materials do not shrink during construction,” says Hansen.

Thanks to the prefabricated elements, Arca Nova Entreprenør is building at a fast pace in Capjon Park: one floor a week. That is just five weeks for a building.

The wall elements for the first building were produced by Punkaharjun Puutaito in Finland, and the floor elements have been produced by a Finnish company, VVR Wood. For the next buildings, Arca Nova Entreprenør will carry out part of the element production at its own factory in Estonia.

Frame with prefabricated LVL elements

In the first three floors, the load bearing structure consists of wall elements, which are made with 67 mm thick Kerto LVL Q-panels. In addition, Kerto LVL S-beams have been glued and screwed on the outside of the elements to stiffen and stabilize the construction. The S-beams are also used for installing an insulation layer. In the two top floors, there is a traditional timber frame construction reinforced with CLT plates to take up the loads.

“We have a stiff, yet elegant and slim structure, which transfers the heavy wind, snow and seismic loads to the foundation made of concrete,” points out Hansen.

The intermediate floor consists of elements, which form a stiff plate to transfer the loads to the end walls and the walls in between the apartments. Each element consists of Kerto LVL Q-panels on the top and Kerto® LVL S-beams as ribs and bottom flange. The unique structure allows floors of up to 9 metres in open span.

Strong connections and highly fire-resistant materials

Various steel plates and parts, bolts, screws and glued-in rods are used together with the floor and wall elements to create a stiff, stable and massive construction.

The wall elements of these multi-storey buildings are connected with bolts to steel plates on the bottom, and the beams are assembled in between the elements with strong steel angles. The frame is connected to the floor elements with adjacent steel parts and massive bolts.

The multi-storey apartment buildings are built according to strict fire-safety regulations. The building has a sprinkler system installed.

The exterior walls are constructed as R90 walls, and the intermediate floor elements are constructed as REI60 floors. Part of the fire concept is the massive use of Kerto LVL, which has 60 minutes fire resistance, which is combined with gypsum boards to provide fire protection layer in the floors.

Long-term cooperation

Hansen talks about Metsä Wood in a positive way. Arca Nova wanted to develop its own construction concept to build tall timber apartment buildings and was impressed with Metsä Wood's Kerto-Ripa design system.

"They have supported our learning with their help and knowledge. It was great to visit Metsä Wood's mill and see showcase buildings in Finland. Our cooperation has been vital for our success to create a new design system for the Norwegian housing market," says Hansen.