A town with wooden Structures: Skellefteå

It looks unbelievable, a town where most of the structures are erected out of wood. This has made Skellefteå a town totally eco friendly, taking care of  challenges of global warming. 

As you come in to land at Skellefteå airport in the far north of Sweden on the Baltic Sea Coast, you are greeted by a wooden air traffic control tower poking up from an endless forest of pine and spruce. After boarding a biogas bus into town, you glide past wooden apartment blocks and wooden schools, cross a wooden road bridge and pass a wooden multistorey car park, before finally reaching the centre, now home to one of the tallest new wooden buildings in the world, so aptly called Plyscraper !

If you are wondering what a climate-conscious future looks like, small subarctic Skellefteå ( literally means in Swedish “she left you”) has some of the answers. In a clearing on its outskirts, Europe’s largest battery factory is currently under construction. The next generation of electric vehicle batteries will not only be produced here, but recycled too. Electric helicopters will soon be able to shuttle visitors to the gargantuan Northvolt gigafactory, while longer-distance electric aeroplanes are being tested nearby.

The Skellefteå township runs on 100% renewable energy from hydropower and wind, and recycles 120,000 tonnes of electronic waste a year, with excess heat from the process fed back into the city-wide heating system. And now, nosing 20 storeys above the low-rise skyline, Skellefteå has a fitting monument to its carbon-cutting credentials. The Sara Cultural Centre and its towering Wood Hotel stand as beacons of what it is possible to do with timber – and store about 9,000 tonnes of carbon from the atmosphere in the process.

The town has now a twenty story building floors high made out of the wood. Three teams of structural engineers, and the region’s prefabrication expertise made it possible to create this timber tower now stands as a blueprint for a new generation of “plyscrapers” The technology behind it is surprisingly simple. The two main materials are glued laminated timber (glulam) and cross-laminated timber (CLT). The former is made from layers of lumber bonded together, with the grain running in the same direction, giving it a higher load-bearing capacity than both steel and concrete, relative to its weight. It is ideal for columns and beams, and forms the structural bones of the cultural centre, which is home to two theatres, a museum, an art gallery and a library.

CLT, meanwhile, is like super-sized plywood, with each layer stuck at right-angles to the next. This makes it strong in all directions, so it is perfect for walls and floor slabs. The lift cores at either end of the 20-storey tower are made from CLT, with prefabricated hotel room pods stacked between them, incorporating glulam columns in their corners for strength. Finally, the double-skin glass facade keeps the rooms insulated in winter and cool in summer, as the warmed air rises between the panes of glass.

The “self-finish” nature of structural mass timber, which can simply be left exposed, means that the tower was incredibly quick to build, doing away with the usual wet trades of plastering and decorating. A whole year was saved by using wood, compared with steel and concrete, with a storey completed every two days. The number of truck deliveries was also reduced by about 90%, with practically zero waste on site. Like bits of a giant balsa-wood model, the pieces came from factories ready to be bolted together, some in panels 27 metres long, while the trees were harvested from within a 60km radius of the site – and have all since been replenished. Just like the region’s forest-foraged restaurant menus, this is meaningful local sourcing rather than a green veneer.

The climate isn’t the only beneficiary. Building in wood seems to have a positive effect on construction workers. While a normal building site is a noisy, toxic place of fumes and dust, a timber one is a picture of serenity. The people building this would never go back to steel and concrete, which is analysing improvements to its workforce’s mental health following the project. There’s one downside, though, at least from the hotel perspective: The raw wooden walls absorb stains like red wine much faster than a painted wall.