Rethinking mass timber -is it a sustainable building solution?

In an interview with the online magazine Dezeen, Benjamin Kromoser, the leader of the Institute of Green Civil Engineering at the University of Natural Resources and Life Sciences in Vienna, expressed his opinion that mass timber may not become a mainstream building product due to its high wood consumption. Kromoser argues that while using wood can reduce the embodied carbon footprint of buildings, the building industry’s main challenge is to use fewer raw materials overall, rather than simply switching from concrete and steel to biomaterials like wood.

He claims that using wood does not automatically make a building sustainable because the industry needs to focus on minimizing the environmental impact of buildings throughout their entire lifecycle. He predicts that the use of mass timber will increase in the next few years, particularly in countries like Sweden and Norway, where a significant number of cross-laminated timber production facilities have been built. However, he believes that the maximum potential of mass timber will not be reached for at least ten years, and it will not become a dominant building material.

Kromoser argues that using mass timber is not the most efficient way to increase the proportion of construction that uses wood. Instead, he believes that material-efficient methods like timber framing should take precedence over relying on engineered wood. To produce one cubic meter of cross-laminated timber or glulam, around 2.5 cubic meters of wood are required, roughly 25% more than for timber-frame construction. Thus, in an effort to achieve material reusability, Kromoser suggests that the main application of mass timber should be for creating cantilevers or bearing heavy loads or for living spaces in attic rooms because of its thermal massing properties.