Global warming potential of multi-storey timber buildings

Constructing high-rise buildings using timber has been suggested as a strategy to reduce the construction sector’s carbon footprint. Various studies have already investigated the differences in the global warming potential (GWP) of a multi-storey building when it is redesigned in timber. This study performs a meta-analysis of the existing literature concerning the potential reductions in greenhouse gas emissions achieved by timber high-rises. For this, 42 comparative life cycle assessments (LCAs) and additional relevant literature were collected through an online search. The parameters used are the GWP and the operational energy consumption per unit of area. This was investigated for the different life phases as well as for the full life cycle. The outcome was unanimous: for all the studies that included all life phases, the timber variant of the multi-storey building caused the least carbon dioxide emissions. The reduction in GWP between the concrete and timber benchmark of the building ranged from 2.69% to 677.61%. Between steel and timber, the GWP reduction varied between 1.20% and 144.11%. This wide range in results is attributed to the diversity of considered parameters in an LCA, each of which can have different assumptions and scenarios applied.