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The myth claims that Northern Norwegian spruce is unsuitable as a building material. Researchers now have the answer
Large areas of Northern Norway were planted with spruce trees in the 1940s and 1950s. These forests are now mature and ready for harvesting. But can the timber be used?
Published
It has been claimed that spruce timber from northern Norwegian has too low density and insufficient strength properties to be used in load-bearing structures.
But is this true? Is spruce timber from Northern Norway unsuitable for use as construction materials?
Together with researchers and master’s students at the Norwegian University of Life Sciences (NMBU), NIBIO’s Eirik Nordhagen has investigated the quality and strength properties of sawn timber from Northern Norwegian spruce.
The aim was to determine whether the material meets the Norwegian standard for use in load-bearing structures.
Most of the harvest is now sent south
In 2025, more than 200,000 cubic metres of spruce were harvested in the counties of Nordland and Troms. Half of this was sawlogs, with a market value close to 8.3 million euros.
In total, there are just over 24 million cubic metres of spruce forest in Nordland, Troms, and Finnmark. More than half of this is classified as ready for harvesting.
“This could become an important resource for the region in the future. However, this depends on northern Norwegian spruce timber being competitive, both in price and quality," says Eirik Nordhagen.
He is a senior engineer at the Norwegian Institute of Bioeconomy Research (NIBIO).
Today, most of the harvested timber is shipped out of the region, either south within Norway or abroad.
Ideally, more of the timber could be processed locally, providing greater income for local forest owners. At the same time, the area has a shortage of larger sawmills.
Temperature and age affect density
“In general, a colder climate in Northern Norway causes the trees to grow less during late summer and autumn than in Southern Norway,” says Professor Geir Vestøl at NMBU.
He refers to studies from the 1980s, where researchers found lower density and lower strength properties in Northern Norwegian spruce compared with spruce from Southern Norway.
“Spruce trees in Northern Norway have, on average, somewhat lower density. But in certain areas, the levels are comparable to those in the south,” Vestøl says.
Density and fibre length are crucial for strength. Earlier research shows that both increase with the age of the tree.
“Narrower annual rings in the outer parts of the tree lead to increased strength and stiffness,” Vestøl explains.
And as the years pass, and the arctic spruce grows older and thicker. The added annual rings might also influence timber quality.
From pilot study to testing real timber
A pilot study in 2022 gave reason for optimism. The results suggested that both density and fibre length increase with the age of the tree. This could make it more suitable for structural use.
The researchers therefore proceeded with a full-scale study of sawn timber produced from northern Norwegian spruce.
To be used in construction, timber must meet strict requirements for strength and stiffness, including parameters such as modulus of elasticity and bending strength.
The modulus of elasticity (E-modulus) is a measure of the stiffness of the wood. Bending strength indicates how much force is required before a plank breaks when it is bent.
A total of 848 planks were tested. The material came from nine different forest areas, ranging from 65 to almost 70 degrees north – from Hattfjelldal in the south to Lyngen in the north – as well as Lutz spruce from the coastal areas Lofoten and Vesterålen.
The timber was sawn locally and dried at Begna Bruk in southern Norway before being tested at NMBU’s wood lab.
Northern sawn timber meets quality requirements
The results show that density, stiffness – and partly the strength – of northern Norwegian planks is significantly higher than what was found in studies from the 1980s.
“The improvement is likely due to the material being sourced from older forests, especially in Troms and Salten,” Vestøl explains.
Although the average values are still somewhat lower than for spruce from southern Norway, Vestøl considers this to be within expected climatic differences.
However, there is no doubt in his mind that spruce sawn timber from northern Norway meets the required standards.
“We have now tested real sawn timber, and we are pleased with the positive results. This is not just theory – northern Norwegian sawn timber is of good quality,” he says.
The study shows that:
- Spruce from Nordland and Troms graded as T1 meets the requirements for C18.
- Timber graded as T2 or better meets the requirements for C24.
- T3 does not meet C30 requirements in all areas.
“In practice, this has little significance, since C24 is the most used class in the construction industry. C30 also requires machine strength grading,” Vestøl adds.
Spruce forests in Nordland – a growing resource
Nordland is Norway’s largest afforestation county. There is a strong focus on making both forest owners and municipalities aware of the value of spruce.
Runa Stenhammer Aanerød is an adviser at the Nordland County Governor. She points out that forests in the north are less studied than those in the south, but that the potential is significant.
“Nordland’s spruce forest is a rapidly growing resource that could provide increased economic contributions to the forestry sector in the future,” she says.
A resource that must be actively managed
NIBIO’s Eirik Nordhagen emphasises the long-term perspective. After World War II, major efforts were made in forest planting as a future resource for agriculture.
“Today, large quantities of spruce timber is available in northern Norway. A resource that can be harvested and further processed,” he says.
He points out that growing conditions are good, and that climate change may further enhance growth.
“The results point in one direction: The quality of timber in the boreal coniferous forest is shaped over time through forest management and active use,” he says.
At a time of increasingly uncertain global supply chains, this becomes even more relevant, he believes.
“Our northern forests are not a passive reserve that can easily be exploited during times of emergency. They must be actively managed if they are to function as a local and resilient source of renewable raw materials,” he says.
"Let the forest mature properly"
Nordhagen also highlights the potential for local processing.
“Much of the timber can be used as sawlogs and further processed locally into building materials. But it's important that the forest is allowed to grow sufficiently before harvesting. That is when it can deliver the greatest value,” he says, adding:
“Let the forest mature properly. Then both the resource and the sawlogs can be processed locally."
Northern Norwegian spruce timber is therefore a renewable resource that could play a major role in the construction industry in the north in the years ahead.
Reference:
Vestøl et al. Gran i Nord - Egenskaper til konstruksjonsvirke av gran og lutzgran fra Nordland og Troms (Spruce in the North – Properties of construction timber from spruce and Lutz spruce from Nordland and Troms), NIBIO research report, 2026. DOI: 10.21350/gx1p-x944
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