Overview of Building LCA from the Sustainability Rating Tools Perspective

This study analyses the most representative features of Life Cycle Analysis (LCA) applied to the building sector concerning the environmental impacts of materials and products, through the study of the most shared criteria among four international sustainability rating tools: LEED, BREEAM, DGNB and Green Star. Since 2006, LCA has been internationally standardised with ISO14040 and ISO14044, making it a globally used tool for the environmental assessment of materials, products, building services and whole buildings. The European Commission, through the CEN technical committee (CEN/TC 350), developed the EN15804 and EN15978 standards to stimulate transparent communication about the environmental impacts of buildings and to try to reduce obstacles and limitations in construction industry application. This approach has strengthened knowledge and awareness of environmental impacts, driving designers, producers, stakeholders and policy makers towards more responsible choices and behaviours. Nevertheless, when it comes to buildings, different modalities of usage as well as difficulty in data collection, calculations and projection of service life scenarios, have led to different interpretations of the outcomes, increasing the challenge of accomplishing a comprehensive analysis. Due to this level of complexity, the building sector has not yet been able to exploit the potential of LCA as other sectors, showing a need for simplification and harmonisation. This paper aims to identify the most representative characteristics of the LCA approach applied to buildings, through the analysis of the most common/shared features taken into account by four major international Sustainability Rating Systems (LEED, BREEAM, DGNB and Green Star) that are multi-criteria based protocols able to evaluate a number of indicators providing, eventually, an overall score of buildings sustainable performance. The components considered within the analysis include: life cycle phases considered, impact categories and environmental indicators adopted, databases sourcing (involving the integration with EPDs) as well as calculation and benchmarking methods applied, aiming at tracing a way for simplification thus a greater spread and utilization of the LCA approach within buildings environmental performance assessment.