Subsequent in our Timber Revolution collection is a profile of Mjøstårnet, an 85.4-metre-high tower in Brumunddal, Norway, that was one of many world’s first true timber skyscrapers.
The 18-storey mixed-use constructing was named world’s tallest timber constructing by the Council on Tall Buildings and City Habitat (CTBUH) when it was accomplished in March 2019, comfortably surpassing the 53-metre Brock Commons Tallwood Home in Vancouver.
Structure studio Voll Arkitekter believes that the milestone demonstrated what the way forward for sustainable structure might seem like.
“Wooden development has gained a brand new renaissance and we’re proud to have the ability to assist picket structure attain new heights,” Voll Arkitekter companion Øystein Elgsaas instructed Dezeen.
“Mjøstårnet just isn’t the blueprint of a tall timber constructing however a contributor to additional sustainable improvement,” Elgsaas added.
“Sustainable-wise, an important side of our constructing was to indicate that it’s doable to construct giant, complicated timber buildings, and in that vogue, encourage others to do the identical.”
Positioned on the shore of Norway’s greatest lake, Mjøsa, which lends its title to the constructing, the 18-storey tower incorporates flats, a resort, workplace area and a restaurant.
It was constructed utilizing two forms of engineered wooden: cross-laminated timber (CLT) and glue-laminated timber – also referred to as glulam. As a result of each sorts of wooden are fashioned of layers of lamellas glued collectively crosswise, they’re considerably stronger than commonplace wooden.
Giant glulam trusses comprised of light-coloured spruce wooden help the construction alongside its facades in addition to forming its inside columns and beams. In the meantime, CLT was used to help the constructing’s three elevators and two staircases.
The structural mass timber was left uncovered inside, making the tower fast to construct. The groundwork for the undertaking started in April 2017 and the primary timber development occurred simply six months later.
The studio was notably eager to make use of timber due to its sustainability credentials. Bushes act as carbon sponges, absorbing atmospheric carbon which is then locked up within the wooden and saved within the constructing.
Wooden can also be much less carbon-intensive to fabricate, transport and assemble than concrete, which means that the manufacturing course of has decrease embodied carbon emissions. The embodied carbon from buildings product of metal and concrete quantities to 11 per cent of worldwide carbon emissions.
“Wooden is a greater possibility than concrete relating to the carbon storage within the materials itself,” mentioned Elgsaas.
“The place you historically want a big quarry to supply the fabric for the concrete manufacturing, it leaves giant scars within the atmosphere that do not ‘heal’ in the identical manner as a big space used for harvesting bushes does,” he continued.
“A sustainably managed forest and harvesting of the bushes would truly profit the world’s organic variety.”
Norwegian regulation requires forest house owners to make sure harvested areas are “regenerated inside three years”.
Brumunddal’s proximity to a serious forestry and wooden processing hub meant that the supplies for Mjøstårnet have been sourced from close by spruce and pine forests.
“The spruce used within the development of the glulam parts, corresponding to trusses, columns and beams, have been sourced regionally within the space of Ringsaker,” Elgsaas recalled.
“The timber is minimize to plain board dimension planks on the native sawmill after which processed at Moelven, the place they make the ultimate glulam merchandise used within the development,” he added. “Moelven is only a fifteen minutes drive from Brumunddal.”
Scandinavia’s entry to giant woodlands provides it an abundance of native wooden sources, fuelling a surge in architects turning to wooden for tasks within the area.
Among the many notable tall timber tasks in Nordic nations is Sweden’s Kajstaden Tall Timber Constructing by CF Møller Architects and Finland’s tallest picket condominium block, Puukuokka, by OOPEAA.
Based on Elgsaas, the timber trade has modified since Mjøstårnet was constructed and public scepticism over the potential of timber for tall buildings has subsided.
“The give attention to the atmosphere and the advantages of utilizing wooden has modified dramatically since we started our undertaking again in 2015,” he mentioned.
“Individuals have found the chance and advantages of utilizing completely different constructing supplies and that there isn’t a longer a predetermined answer to what a bigger and extra complicated constructing may very well be comprised of.”
Though the studio was dedicated to utilizing timber, the fabric didn’t come with out its points. The inherent lightness of timber proved tough for the architects as a result of the highest of the constructing was vulnerable to shifting within the wind.
“Peak accelerations attributable to wind on the highest flooring of Mjøstårnet is on the restrict of what’s acceptable for residential buildings,” mentioned Elgsaas.
“The acceleration within the motion is faster than in a heavier constructing of metal and concrete and if not stored inside the required ranges, it might result in nausea.”
Architects create composite buildings – wood-concrete-hybrid constructions or timber frames with concrete cores to keep away from this drawback. Nonetheless, Voll Arkitekter determined to include concrete inside Mjøstårnet’s flooring to offer it the required sturdiness and weight.
“We elevated the load on the higher flooring: flooring 12 to 18 are 300 millimetre-thick concrete product of a precast component on the backside and an in-situ layer of topping concrete,” Elgsaas defined.
“Changing wooden flooring with concrete flooring on the higher flooring meant that the constructing could be heavier in the direction of the highest and that will decelerate the acceleration within the motion of the constructing when affected by wind forces.”
In 2022, Mjøstårnet was overtaken because the world’s tallest timber constructing by Ascent, an 86.6-metre-tall tower in Wisconsin, which was designed by Korb + Associates Architects.
An all-timber constructing is classed as such by the CTBUH if each the principle vertical or lateral structural parts and the ground are constructed from timber.
Ascent is unlikely to carry the highest spot for lengthy, as a 100-metre-tall housing block in Switzerland timber constructing by Danish studio Schmidt Hammer Lassen is about to turn into the world’s tallest when it completes in 2026.
The images is by Ricardo Foto until said in any other case.
Timber Revolution
This text is a part of Dezeen’s Timber Revolution collection, which explores the potential of mass timber and asks whether or not going again to wooden as our main development materials can lead the world to a extra sustainable future.
