Steel–Timber Hybrid Buildings: A Comparative Life Cycle Assessment Study of Global Warning Potential Impacts
Dario Trabucco, Giovanni Perrucci
Abstract
Mass timber buildings are gaining momentum, as they are seen as an environmental alternative to conventional concrete and steel structures, and they are also being used for mid- and high-rise buildings. This study conducted a comparative LCA analysis of 20- and 40-story building structures made with different combinations of steel and mass timber. The results show that, even disregarding the environmental benefits of the sequestered biogenic carbon by using a 0/0 approach, timber-based structures result in a roughly 25% lower Global Warming Potential (GWP) impact than steel- or hybrid-based equivalent solutions. The results show that the contribution of steel does not bring any GWP advantage (an average increase of 20% is reported); however, steel–timber hybrid structures may still be the only viable solution to attain greater heights. This study also evidences that materials with lower GWP in their production phase can present a viable solution even when long transportation is required, highlighting the importance of the production phase to reach environmental targets.