A systematic review of consequential life cycle assessment in whole building life cycle assessment

Achieving global carbon neutrality by 2050 requires substantial decarbonization of the built environment, with LCA playing a critical role in evaluating buildings' environmental impacts. Among the primary LCA methodologies, CLCA offers unique decision-support capabilities but faces limited adoption in the building sector, restricting its effectiveness. This study investigates the methodological challenges contributing to the low adoption of CLCA, focusing on issues such as goal and scope definition, consequential life cycle inventory (CLCI) modelling, and uncertainty analysis. A systematic review of 20 building-related CLCA studies was conducted using an adapted CLCA framework based on the step-wise process by Weidema et al (2009). Studies with strong alignment to the framework provided robust insights into decision contexts, market dynamics, co-products, and uncertainty analysis, enhancing transparency and replicability. Conversely, studies with significant gaps struggled with poorly defined decision contexts, insufficient data, and the omission of uncertainty analyses, reducing their reliability and applicability. This review underscores the growing potential of CLCA in sustainability assessments within the built environment. However, technological constraints, data limitations, and methodological complexities hinder its broader adoption and comparability. A tailored CLCA framework for the construction sector is proposed to address these gaps, incorporating decision trees, standardized templates, and uncertainty analysis guidelines to improve transparency, robustness, and decision-making support in achieving a low-carbon built environment.