The Preferability Framework - Enabling life cycle sustainability assessment meta studies

Reviewing and comparing results from Life Cycle Sustainability Assessments (LCSA) is both crucial and tricky at the same time. Policy decisions, for example, must be based not on single studies but the collective knowledge embodied in the existing literature. However, many degrees of freedom in designing LCSA studies often lead to anecdotal evidence, preventing meaningful resumes and comparisons of studies. In this paper, we develop a framework to overcome the challenges of limited comparability between LCSA studies applying our Preferability Framework. Using especially descriptive statistics, we analyze the obtained results that are not directly influenced by methodological choices or further assumptions within one case study. Results are thus (more) comparable. To test our approach, we apply the framework to the case of timber as a building material compared to suitable alternatives (e.g., steel or concrete). Comparing 45 studies (obtained from a structured literature review), we gain meaningful results in the environmental and economic dimension compared to other approaches, highlighting the preferability of timber over other materials and reinforcing our framework's suitability. Further, we demonstrated the use of our framework reviewing social Life Cycle Assessment studies. With the easy-to-understand but insightful results of our framework, we advance the field of LCSA and enable scientific-based recommendations for economy, policy, and society.