Manager Structural Systems, Kaveh Andisheh, and Senior Structural Sustainability Engineer, Amir Shah Mohammadi, discuss Mass Timber’s Viability as a Sustainable Building Material
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.
Promoting Material Reusability and Efficiency: HERA’s Circular Design Strategies and Research for Sustainable Construction Practices
In response to the concerns emphasized by Benjamin Kromoser, the Heavy Engineering Research Association New Zealand (HERA) recognizes the importance of reducing the use of raw materials in the construction industry by promoting steel reusability and circular design strategies. HERA is currently engaged in circular design research, which aims to create buildings and infrastructure that are regenerative, adaptable, and resilient. In an effort to promote material reusability, HERA is also currently developing a steel circularity passport that records the origin, quality, and quantity of materials used in a building throughout its lifecycle. This information can be used to promote the reuse of materials, thereby promoting a circular economy. This project will create the first material passport in the Australasian construction sector, serving as a proof of concept to significantly assist the New Zealand construction sector in developing material passport capability for other building components and materials.
Furthermore, HERA, in a project cofounded by BRANZ, will develop a framework and a pilot to assist structural engineers and other practitioners in efficient designing low carbon buildings. The deliverables will include a material and typology-agnostic design guidance framework that can be used by the sector as a template to achieve the lowest embodied carbon throughout the entire lifecycle. The development of this framework and the specific guidance pilot will assist the construction sector in proactively responding to the impending changes being introduced by MBIE via the Building for Climate Change program.