Dynamic life cycle impact assessment (DLCIA) in a sustainable building planning process

Building sector significantly contributes to the anthropogenic environmental impacts. To promote sustainable construction, life cycle assessment (LCA) serves as a useful tool to quantify the environmental impacts of a building and suggest improvement solutions. It is widely acknowledged by various regional and international regulations and is mandated for new buildings in the European Union. While the conventional LCA often fails to capture the dynamics in a building's life cycle, this study enhances the plausibility of building LCA by implementing a dynamic life cycle impact assessment (DLCIA) for a solid masonry building, evaluating improvement solutions across its product and End-of-Life (EoL) phases. Our DLCIA approach, aligned with Intergovernmental Panel on Climate Change Assessment Report (IPCC AR) 6, provides a transparent and clear calculation process of global warming potential (GWP) overtime and a comprehensible comparison with the conventional static calculation. We demonstrate that the dynamic GWP calculations based on the DLCIA approach are consistently 5-7% higher than static counterparts, successfully capturing the continuous decay of GHG emissions in the atmosphere and the environmental impact of each emission event. Applied to improvement solutions, this method guided strategies that achieved a 31.52% reduction in total GWP. Furthermore, integrating a dynamic circular recycling model into the improvement solutions in the EoL phases highlights the potential of combining multiple dynamic factors and critically discusses the concept of circular economy. To promote circular economy in construction, it is essential not only to improve the conversion rate of waste materials into compounds for virgin materials but also to explore cross-material recycling and recycling among multiple building entities. Future dynamic LCA (DLCA) studies should integrate DLCIA with other dynamic factors to enable more comprehensive and systematic assessments.