If you live near a forest, why would you build a skyscraper with cement? Especially if you are focused on helping to create a circular economy, and you know that wood can capture and hold the carbon that is warming our world while cement adds carbon to our air.

Skellefteå, a Swedish city situated near the Arctic Circle which is expected to grow from 72,000 to 80,000 inhabitants by 2030, is working to wean the local construction industry off environmentally-harmful materials by encouraging much greater use of wood. The city has relied on its nearby forestland to construct buildings from as early as the 18th century. From a timber bridge stretching across the local river, to a three-storey parking garage in the city centre, everything in Skelleftea feels like it’s made from the trees that surround it. In most cases, it really is, says EuroNews.

The United Nations Environment Programme says construction was responsible for over 38% of global energy-related carbon emissions in 2015 alone, while cement production is the world’s largest single industrial emitter of CO2. Wood, on the other hand, sequesters carbon dioxide, binding it from the atmosphere and storing it for good.

The new Sara Kulturhus Centre, which opened last September, is home to six theatre stages, a library, two art galleries, a conference centre and a 205-room, 20-storey hotel and is the world’s second tallest wooden tower, just 10 metres shorter than the Mjøstårnet building by Voll Arkitekter in Brumunddal, Norway. It is named after Sara Lidman, one of Skellefteåbygden’s many famous authors, who “has inspired us to create a culture house that exudes courage and the will to think new”.

It is a carbon-negative building, says its lead architect Robert Schmitz. “Embodied carbon emissions from materials, transport and construction as well as carbon emissions from operational energy during 50 years are less than the carbon sequestration in wood within the building.” The building is expected to have a lifespan of at least 100 years.

Not only was its construction carbon neutral, it is powered by renewable energy sources – a geothermal heat pump and 1,200 square meters of solar panels on the roof will provide most of the power to the building, while the rest will come from renewable sources.

Through its lifetime, the building will capture nine million kilograms of carbon dioxide – as much as 10,000 forests, says EuroNews.

As a landmark in the city, the building serves as a “showcase for sustainable construction,” the architects say. At a Dezeen talk in Stockholm in 2020, White Arkitekter CEO Alexandra Hagen pledged that every building the studio designs after 2030 will be carbon negative.

“Climate change is the most important challenge for the future for this decade,” she said. “We know that the materials used for products and for buildings are the major cause of carbon emissions. So we have to use our abilities as designers to transform into a circular economy.”

The building’s structure was designed to use engineered timber in order to take advantage of locally grown wood, which was processed at a sawmill around 30 miles from the site.”We chose to work with a timber structure to make the building as sustainable as possible, the forest being an abundant local resource, and to build on the local timber knowledge and tradition from century-old houses to modern-day engineered timber,” White Arkitekter partner Oskar Norelius told Dezeen.

And it is not just skyscrapers that are being built from wood. Swedish construction firm Lindbacks, which specializes in prefabricated wooden buildings, is now working on a new timber apartment project to house the city’s new arrivals. “A good thing with the wooden frame is that you can change it over time, which you can’t do with houses,” says the firm’s head, David Sundstrom.

Carbon-sequestering wood currently accounts for over 20 per cent of all new multi-storey buildings in Sweden, says Tomas Alsmarker, head of innovation at Swedish Wood. The country has seen a huge change over the last five years – once it was forbidden to build wooden homes above two storeys high, but now wood is the material of choice in the country with the largest percentage of forestland in Europe.

“For all buildings up to eight storeys high, the question is not whether it’s possible to do it in wood,” he says. “You should ask why we should not do it in wood.”

Sources:

Sara kulturhus finalist in international competition for wooden architecture. Swedish Wood, Mar. 31, 2022

Sweden’s innovative wooden skyscraper captures as much carbon as 10,000 forests. EuroNews, Mar. 28, 2022

Sara Cultural Centre – One of the World’s Tallest Timber Buildings. Smart City Sweden

White Arkitekter unveils “carbon negative” skyscraper and cultural centre in Sweden. Dezeen, Oct. 8, 2021

More reading:

The World’s Tallest Timber Tower Could Be the Future of Sustainable Construction. YES Magazine, Sep. 27, 2021

Subarctic Sweden Is at the Forefront of a $100 Billion Green Tech Boom. Bloomberg, Feb. 14, 2023