Mass timber’s popularity because the go-to low-carbon building materials is a problematic oversimplification that’s resulting in greenwashing, says carbon skilled Amy Leedham on this Timber Revolution interview.
“We’re seeing somewhat little bit of oversimplification and glorification of mass timber,” stated Leedham, who’s carbon lead at engineering consultancy Atelier Ten.
“The primary factor that you just see within the media, and one of many causes it is changing into such a preferred constructing materials, is that it may possibly have a considerably decrease embodied carbon than metal or concrete,” she instructed Dezeen. “I say ‘can’ as a result of it is not at all times the case.”
Mass timber is a time period for engineered-wood merchandise – sturdy structural elements that usually include layers of wooden bonded collectively.
It’s rising in reputation within the building business as a consequence of wooden’s means to sequester carbon, which implies timber typically has a decrease embodied carbon when in comparison with supplies similar to concrete and metal.
Nevertheless, in response to Leedham, this has precipitated mass timber to turn into synonymous with carbon neutrality, resulting in the fallacy that every one “mass-timber buildings are carbon impartial” because of the saved carbon offsetting the emissions expended by them.
“Essential components that should be thought of”
“Mass timber building can positively be an necessary pathway towards carbon neutrality, however there are different crucial components that should be thought of,” she instructed Dezeen.
“If it is not completed properly, mass timber buildings can have very excessive carbon emissions, whereas concrete buildings can have fairly low carbon emissions,” she stated.
“We have labored on concrete initiatives with sure concrete suppliers the place they’re actually specializing in decreasing emissions related to the concrete mixes and people can have fairly low carbon emissions. There isn’t any black and white, it is all hues of gray.”
Carbon neutrality is achieved when no further carbon dioxide is added to the ambiance within the creation and operation of an entity, similar to a constructing. This will both contain eliminating emissions within the first place, negating emissions by offsetting, or a mix of each.
Assuming that utilizing mass timber achieves this by its sequestered carbon alone can overlook a number of components, such because the carbon footprint of different supplies used to assemble wood buildings, together with the inside finishes.
“Mass timber buildings have a number of different materials in them, particularly in locations the place the code is difficult, particularly for taller mass timber,” Leedham stated.
Moreover, the carbon footprint of mass timber will also be impacted by how and from the place the wooden was sourced and transported, and what occurs to it on the finish of its helpful life.
If the wooden utilized in a constructing’s building results in a landfill, it’s more likely to be incinerated or left to decompose, with its sequestered carbon launched again into the ambiance – cancelling out the carbon advantages.
“We are able to solely management as much as the purpose that the constructing is constructed”
“Forestry practices are tremendous necessary to the general carbon impression of mass timber, in addition to end-of-life remedy,” defined Leedham.
“As designers and engineers, we will solely management as much as the purpose that the constructing is constructed. We are able to design in sure elements in order that it may be handled properly on the finish of its life in 100 years, however we do not know what is going on to occur.”
The overlooking of those “crucial components” lately prompted Leedham to put in writing a collection of myth-busting essays on engineered wooden, co-authored and revealed with US studio Lever Structure.
The essays shine a light-weight on the principle misconceptions about mass timber which are circulating within the business, in an effort to show the reality behind them and promote the accountable use of the fabric in structure.
“Mass timber is tremendous necessary to the way forward for low-carbon building,” she stated.
“However it’s additionally actually necessary that it is completed proper. If it is completed incorrectly, then it is simply one other type of greenwashing.”
Alongside the misunderstandings about mass timber and carbon neutrality, the essays additionally debunk beliefs that “all wooden is nice wooden”, that it’s at all times extra sustainable than concrete, and that mass-timber buildings truly take in carbon.
Co-author Jonathan Heppner, who’s a principal at Lever Structure, stated the authors have heard these myths in discussions about their very own initiatives, but additionally at business occasions.
“These myths emerge very steadily”
“Variations on these myths emerge very steadily the place architectural and engineering professionals meet to debate building and procurement with undertaking homeowners, builders, producers and commerce representatives,” Heppner instructed Dezeen.
“These myths floor at symposiums, commerce reveals, conferences, lectures, or in convention rooms the place choices across the incorporation and development of mass-timber techniques are being mentioned,” he continued.
Each he and Leedham hope their publication will contribute to “extra nuanced narratives from the mass timber business” and advocate “wholesome innovation” on this area.
Within the essays, the authors define how the business can fight these myths – similar to by encouraging architects to make conscientious sourcing choices, which might, in flip, incentivise the timber business to handle forests sustainably, and by bettering understanding of carbon neutrality and the way it may be achieved.
Leedham instructed Dezeen that these options might additionally all be supported by the roll-out of worldwide carbon taxes for building initiatives, which might require funds for the greenhouse gasoline emissions emitted by constructing elements.
Not solely would this result in the extra accountable use of mass timber, she stated, however it might additionally encourage extra sustainable practices with regards to utilizing supplies similar to concrete and metal.
“Carbon taxes would positively velocity up the adoption of any kind of extra sustainable building observe,” stated Leedham.
“In the event you needed to pay for all of the carbon emissions earlier than you bought your constructing allow, I believe that may encourage the usage of mass timber, it might encourage sustainable forestry practices, and it might truly encourage each the concrete and metal business to cut back their emissions.”
Mass timber won’t “dominate the business”
This final level is especially necessary as she believes that concrete and metal will stay very important supplies in the way forward for structure.
“The truth is that we want every part. Mass timber is considered one of a package of elements,” stated Leedham.
“I do not suppose mass timber goes to ever dominate the business, simply due to the sheer quantity of building that is occurring, and I do not suppose it desires to.”
“We completely want metal and concrete industries to additionally deal with decreasing their emissions as a result of we’ll want all three major structural supplies,” she added.
This echoes the views of building materials skilled Benjamin Kromoser, who instructed Dezeen in an interview that mass timber won’t turn into a mainstream constructing materials as a result of it makes use of an excessive amount of wooden
“Wooden is a restricted useful resource,” he stated. “It at all times must be a stability between what we take from the forest to make use of for constructing building and the way a lot grows once more.”
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 major building materials can lead the world to a extra sustainable future.
