An operational methodology for applying dynamic Life Cycle Assessment to buildings

While the Life Cycle Assessment (LCA) method is a powerful tool for environmental performance evaluation, the current LCA methodology faces some limitations in evaluating environmental performances of systems with a long time scales, such as buildings. Building systems have particularly long lifetimes as compared to other products or services. They are composed of elements that evolve over time and are characterized by time-dependent parameters. A literature review was performed in the aim of identifying the time-dependent characteristics of a building system at different levels: building technology level (e.g. technical performance degradations and technological innovations), end-user level (e.g. occupant behaviour) and external system level (e.g. infrastructures, energy mix, regulations). A new LCA framework including the time dimension, applied to a building system, is proposed. It involves operational and reproducible tools (computational software and databases) to perform effective temporal evaluations and incorporates dynamic Life Cycle Inventory (LCI, including the temporal evolution of a building system and of the related environment interventions, i.e. emissions and resource consumption) and dynamic Life Cycle Impact Assessment (LCIA, climate change and toxicity). To integrate the specificities of buildings in dynamic LCI modelling, different existing assets (at national and international level) in the field of LCA are analysed. This work proposes an original methodology for performing a dynamic LCA of buildings using new tools still under development.