trends
Carbon-negative construction While these wooden high-rises may begin their life in the same forest as a log cabin , the components used in mass timber projects are much less rustic . In the Ascent , thick glue-laminated timber beams replace steel girders , while the floor is constructed from cross-laminated panels , in which thin sheets of timber are layered perpendicular to one another .
Unlike traditional steel or concrete alternatives — which respectively contribute around 1.89 tons and 0.622 tons of CO 2 emissions for every ton produced , due to the significant amount of heat used in the production process — engineering a ton of gluelaminated timber produces only 0.28 tons of CO 2 . Add in the fact that a cubic yard of wood absorbs around 0.85 tons of CO 2 during its growth , and the production of engineered timber products ends up as a net negative for CO 2 emissions .
“ Our industry is disproportionately high in terms of energy consumption , so we need to do anything we can to reduce our CO 2 emissions ,” explains Jordan Komp , associate principal at Thornton Tomasetti , the structural engineering firm behind the Ascent . “ Engineered timber isn ’ t a new technology , but it ’ s this growing concern for sustainability that is really driving its appeal .”
A cost-competitive building material Beyond the climate imperative to investigate more sustainable materials , the rising costs of steel and concrete are rendering these timber alternatives increasingly cost-competitive .
“ The steel market is crazy right now and , in some cases , materials cost nearly double what they used to a handful of years ago ,” Komp says . “ At this point , mass timber is probably comparable in cost to steel , and a little more expensive than concrete .”
While timber was also impacted by the COVID-19 supply chain crisis , with average costs in the U . K . experiencing a similar price increase to steel , Komp believes that timber is more likely to see an improved supply chain and decreasing costs in the longer term as manufacturers scale up to meet the growing popularity of mass timber construction .
“ Utilizing these forests means generating revenue that can then be put back into managing and maintaining [ them ] in a sustainable manner .”
— Jordan Komp , associate principal , Thornton Tomasetti
An entire floor of beams could be installed in one day .
“ There is a vast amount of underutilized forest land ,” he says . “ Utilizing these forests means generating revenue that can then be put back into managing and maintaining these forests in a sustainable manner that is good for the environment . I 100 % believe it is possible to meet the demand for mass timber from sustainably managed forests .”
It ’ s not only the climate that stands to benefit from mass timber construction methods . Timber can be engineered to provide comparable strength to other construction elements at less than half the weight , meaning foundations don ’ t need to be dug as deep .
“ Your speed of construction and disruption to the environment is also going to be decreased because most
PHOTO ( FAR LEFT ) COURTESY OF WIEHAG TIMBER CONSTRUCTION ; ( LEFT ) BY THOMAS JORDAN ; FACING PAGE PHOTO ( TOP ) BY ÅKE ESON LINDMAN AND WHITE ARKITEKTER ; ( BOTTOM ) COURTESY OF VISIT SKELLEFTEÅ
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