Anthropogenic climate change has been a central focus of the building sector in recent
decades, for good reason. The majority of the carbon emissions that contribute to climate change can be attributed to the built environment, with roughly 40% coming from the construction of vertical buildings. Many different sustainable strategies, techniques, and materials have emerged in the world of design and construction to reduce carbon emissions. Mass timber is one of the new low-carbon design solutions to reduce the carbon impact of our buildings. But what is mass timber? And why should this be used instead of convention-building materials?
A mass timber building is a building whose primary load-bearing structure is made from
solid or engineered wood. A building that utilized wood as just an accent does not qualify as a mass timber building. There are an ever-evolving number of mass timber products that can be utilized throughout the building. Mass timber can be used as a supplement to the traditional steel or concrete structural solution or replace them entirely. This is because mass timber is engineered to meet the same high strength ratings as steel and concrete but is significantly lighter in weight and less carbon-intensive. Mass timber systems also offer greater flexibility compared to steel and concrete.
Mass timber is a great low-carbon, sustainable alternative to carbon-intensive concrete
and steel. Concrete, the most widely used construction material in the world, is responsible for around 10% of global carbon emissions. The component that contributes the most to concrete’s carbon footprint is cement. Cement production emits carbon from the burning of fossil fuels in the manufacturing process and from the chemical reactions during processing. Steel, like concrete, is a carbon-intensive material. Unlike concrete, recycling is a common feature of the life cycle of steel, resulting in a lower carbon impact compared to concrete but still carbon intensive compared to mass timber.
One of the most common concerns around utilizing mass timber comes from the
extraction of the raw material. Even though wood comes from a renewable resource (trees), there is a strong concern that increased extraction rates will deplete this natural resource. From experts in the forestry industry and mass timber construction, this is a nonissue. The wood used for mass timber products is sourced from sustainably managed forests so the timber supply can be used for generations, unlike fossil fuels. Because of code restrictions and the unfamiliarity of mass timber among structural engineers, contractors, and developers, mass timber is not a commonly used structural material. With the increased need for climate action and more education around mass timber construction, more projects will take advantage of this sustainable building system in the near future.