Influences of BIM-LOD and Geographic-Scale Environmental Impact Factors on embodied emissions: The Norwegian context

Life Cycle Assessment (LCA), grounded in Building Information Modelling (BIM), plays a crucial role in minimizing emissions in the Architecture, Engineering, and Construction (AEC) sector. However, the accuracy of LCA outcomes is significantly influenced by BIM’s Level of Development (LOD) and Geographic-Scale Environmental Impact Factor (GS-EIF). Using a Norwegian Timber Building as a case study, this article explores the effects of BIM-LOD and GS-EIF on LCA embodied emissions of the life cycle stage from Cradle to Gate. The findings reveal that lower BIM-LOD levels, such as LOD 200, tend to underestimate environmental impacts compared to higher LOD levels, like LOD 350. For instance, Global Warming Potential (GWP) can increase by 142% when movingfrom LOD 200 to LOD 350. Conversely, transitioning from Global Generic Environmental Impact Data (GLD) to Site Specific Environmental Impact Data (SFD), GWP can fall by up to 95%. This underscores the critical role of using precise environmental impact data to enhance decision-making and improve a building’s environmental performance. The study recommends starting with BIM-LOD 300 and Country-specific Regional EIF data (CRD) during the design development stages to balance accuracy and practicality. Tracking the transition along the BIM-LCA progress further strengthens the robustness of theLCA results. However, it is essential to note that the findings of this study are specific to Norwegian timber buildings and may not apply universally to other building types or materials. Therefore, further research is needed to validate these findings across different building structural types, geographic regions and environmental contexts. • Analysing the influence of BIM-LOD and EIF on the embodied emission. • A case study of a Norwegian timber building. • The Environmental Impact Factor (EIF) has the more significant role in LCA’s results. • Using LOD-300 with the country-specific EIF are recommended for choosing materials.