Sweden is Building the World’s Largest City Made Entirely From Timber
A yellow crane hovers above a building site in Sickla, a former industrial neighbourhood that’s home to one of Stockholm’s biggest real estate projects. But instead of delivering concrete, it’s manoeuvring giant chunks of wood to construction staff working in sub-zero winter temperatures.
This is the beginning of what Swedish property developer Atrium Ljungberg describes as “the largest mass timber project in the world.” On the outskirts of Sweden’s capital, construction of ‘Stockholm Wood City’ began in October, several months ahead of schedule, and is set to provide 2,000 new homes by 2027.
[time-brightcove not-tgx=”true”]The company’s core goal is to improve the sustainability of construction projects. Building with wood instead of concrete and steel in 80% of new buildings would, according to a 2020 study by Aalto University and the Finnish Environment Institute, help offset half of Europe’s construction industry emissions. Atrium Ljungberg is also championing the idea that spending time in buildings made with natural materials can help improve our wellbeing. “We can tell the story about how to build a liveable city, how to add nature into the city and build something sustainable,” says Håkan Hyllengren, business development director for the project. “It’s not just about wood, it’s the whole concept.”
Large-scale wooden building projects are growing in popularity globally. Two years ago, Singapore opened a 468,000 square-foot wooden college campus building. Seattle opened a landmark eight-storey affordable housing block, also in 2023. And in Sydney, a giant timber retail and office space is currently under construction.
But Scandinavia—with both a long tradition of building wooden villas and cabins, and prioritising environmental issues—is perhaps unsurprisingly, ahead of the curve when it comes to ramping up construction of multi-storey mass-timber properties. Norway’s third-highest building, Mjøstårnet, was built out of wood in 2019. Finland’s capital Helsinki already has a small wooden district, completed four years ago, and there are state subsidies designed to promote increased wood use in public buildings. Skellefteå, a small, discreet city in northern Sweden nudged its way into must-visit global tourist rankings after the country’s tallest wooden hotel and cultural center opened there in 2022.
Hyllengren hopes Stockholm Wood City will become “an international showcase” due to its sheer scale. The project is set to become the biggest “mixed-use” wooden neighborhood on the planet—alongside the apartment buildings rapidly taking shape, there’s also a high school opening in the fall, and around 7,000 office spaces will be available within two years.
Like most multi-storey wooden properties, the buildings are largely constructed using an engineered product called CLT (cross-laminated timber). This is made by bonding together layers of wooden panels at right angles, giving it a stiffness and strength that is almost comparable with steel or concrete.
In Scandinavia, it’s easy to produce CLT locally—and sustainably—thanks to the region’s abundance of forests. Around 70% of Sweden is covered in woodland, and in 1903 it became the first nation in the world to require compulsory reforestation. “We don’t have a problem where we will run out of wood,” smiles Hyllengren. “We’ve actually got more forest now than we had 100 years ago, because we replant.”
Hyllengren says carbon emissions can be halved in the building construction process, since wood is lighter and quicker to build with than concrete, limiting the use of heavy machinery and energy. The 2020 research from Aalto University and the Finnish Environment Institute also highlights that wood stores carbon rather than emitting it (since it is made from trees which absorb CO2 from the atmosphere as they grow). Plus, if for any reason a wooden building is no longer needed in the future, it is easier to disassemble than concrete, and the wood can be reused or recycled, further extending its life cycle. Using global data projections based on 50 wooden building projects around the world, the researchers concluded that if 80% of new buildings in Europe had structures, cladding, surfaces, and furnishings made of wood, this could sequester up to 55 million metric tons of carbon dioxide per year by 2040. That’s equivalent to 47% of the European cement industry’s annual CO2 emissions.
Lena Dahl, a senior forest expert for WWF Sweden, says the growing trend for building with wood is supported by environmentalists. “Wood has a lower carbon footprint than concrete or steel, so provided that the wood comes from sustainably managed forests it is a better choice,” she says. However, there are concerns about biodiversity loss linked to forestry. Despite reforestation efforts in Scandinavia, Dahl says extensive logging has led to the decline of some plant and animal species, and argues that Nordic forestry companies need to adapt their management practices to ensure nature remains protected as demand for wood increases.
Another potential challenge for the industry is fire safety. But Hyllengren points out that building regulations in the Nordics are among the strictest in the world, and suggests properly designed and treated engineered wood buildings offer levels of heat protection and durability on a par with conventional building materials. “I think it’s a bigger talking point abroad where you haven’t built with wood before or not as much as we’ve done,” he says. All of the buildings in Stockholm Wood City are required to have inbuilt sprinklers, and CLT tolerates extremely high heat levels. “It’s hard for the wood to actually catch fire,” explains Hyllengren, and if it does, it will char on the outside from around 300°C (626°F), which creates a protective barrier that limits the spread of flames.
Atrium Ljungberg estimates that engineered wood is approximately 10% more expensive to buy than steel or concrete, depending on the project. Hyllengren, however, says that the extra costs can be recouped elsewhere by the company. “You have to look at the whole project,” he explains. Since many wooden building parts arrive preassembled, and you don’t have to mix wood or wait for it to dry, like concrete, this helps save money by saving labor hours, argues the business development director. “By building so much faster than when we build with normal concrete, we can reduce the [project] time,” he adds, pointing out that this also means that tenants can move in and start paying rent earlier.
Inside Atrium Ljungberg’s warm head office, just a few blocks from the emerging Stockholm Wood City, there is a miniature light-up model of what the suburb will eventually look like—and how it plans to reduce inhabitants’ environmental impact. This showcases some of the other cornerstones of the development, which Hyllengren hopes will improve “liveability” and create a “really unique environment.” There will be bike storage facilities, a new subway station and rooftop gardens and solar panels. “Pocket parks” between condo blocks and offices will be populated with wild flowers, designed to improve biodiversity. There will even be neighborhood beehives.
Atrium Ljungberg also hopes the wooden buildings themselves will boost locals’ wellbeing. There is already a small but growing body of academic research linking wooden materials with lower stress levels. “Generally speaking, whenever there have been interviews [of] people visiting wooden buildings, they have said that there’s a kind of fresh feeling and also ‘living in nature’ feeling,” explains Ali Amiri, a sustainable buildings researcher at Aalto University in Finland, and co-author of the 2020 emissions paper. There is currently little research into the greater impact of living or working in wooden properties, although his team is planning a long-term study of young people living in wooden campus accommodation.
Back on the building site at Stockholm Wood City, there are already signs that working with and around wood is having a beneficial impact on the construction team. The material provides a brighter, less grey environment, and not as much heavy, brash machinery is required. “It’s really much better for the workers since it’s more light, there’s less noise—when you work with concrete, there is a lot of noise,” says Sara Coletti, business manager for building firm TL Bygg, which is spearheading the construction side of the project. “It’s a positive environment.”
In Sweden, the proportion of new, multi-storey buildings constructed with wood—or at least with a wooden frame—is currently around 16%, compared to 9% a decade ago. Hyllengren believes that’s likely “to increase a lot in the coming years,” as construction firms increasingly prioritize sustainability and liveability.
At Aalto University, Amiri, the sustainability researcher, is also hopeful that the trend can grow globally—including in the U.S. However his research suggests progress may be slower in countries where there are no local forests, more limited access to affordable engineered wood, specialized construction technologies, and design talent. “Also in countries that are not familiar with wooden construction even in low-rise [homes], it’s going to be harder,” he says.
Hyllengren points out many of the architects, engineers, and construction teams working on Stockholm Wood City have already been involved in similar, smaller projects around the Nordics. He believes the regional buzz around building with wood has led to a “really open” climate that’s enabling its rapid evolution in the region. “Companies are sharing knowledge with each other,” he says, “in a way that I haven’t really seen in the same way in construction with concrete or steel.”