Climate impacts of timber-frame buildings in a life cycle perspective: Implications of static and dynamic modelling approaches for biogenic carbon accounting

This study explores the climate change effects of building with wood structural frames in a life cycle perspective, with a focus on biogenic carbon. Analyses of a timber-frame building are carried out considering fossil and biogenic carbon flows during the production, construction, use, and end-of-life stages of the building. Both static and dynamic life cycle modelling are used and compared, to understand the implications of different biogenic carbon accounting methods, including a simplified approach and an entire chain approach integrating biogenic carbon flows from forestry, construction, and energy sectors. The findings show significant differences between the modelling approaches. Over a 100-year analysis period, the static modelling with simplified biogenic carbon accounting indicates a building life cycle climate impact of 164 kgCO 2 e/m 2 , and is the same when excluding and including biogenic carbon flows. The dynamic modelling with simplified biogenic carbon accounting indicates a life cycle climate impact at year 100 of 199 and 91 kgCO 2 e/m 2 when excluding and including biogenic carbon flows, respectively. The corresponding life cycle climate impact for dynamic modelling with entire chain accounting of biogenic carbon flows is 51 kgCO 2 e/m 2 . The production stage dominates the building's life cycle climate impact, with insulation contributing the most. Overall, the dynamic modelling of biogenic carbon flows across the entire chain results in a significantly lower life cycle climate impact for the building. This study underscores the importance of robust accounting for GHG emissions, including biogenic carbon, to optimize the climate impacts of wood-based buildings. • Climate impact of building with timber frames is analysed in lifecycle perspective. • Static and dynamic approaches are used for modelling the lifecycle climate impacts. • Implications of different biogenic carbon accounting approaches are explored. • Static vs dynamic modelling shows notable differences in calculated climate impacts. • Entire chain biogenic carbon accounting results in lower lifecycle climate impact.