A hybrid life cycle assessment method for construction

TLDR

LCAs evaluate environmental impacts of products and processes, and for construction they assess pollution from building material manufacture, but traditional LCA data often omit upstream processes, while input‑output analysis is complete yet error‑prone, so an input‑output LCA model can inform decisions about which processes to exclude. The study proposes a hybrid LCA method for construction that uses national input‑output data to fill gaps left by traditional LCA data. The hybrid method combines traditional LCA data with national input‑output data to cover missing upstream processes. The hybrid approach achieves comparable overall framework completeness regardless of data detail level.

Abstract

Life cycle assessments (LCAs) are used to evaluate the environmental impacts attributable to products and processes. For construction projects, LCAs can be used to assess the pollution associated with the manufacture of building materials for the construction process. Despite the reliability of traditional LCA data, many upstream processes are excluded, which adversely affects overall reliability. Input-output analysis is systemically complete, but is subject to inherent errors when applied to the LCA of specific products. Analysis of an input-output LCA model provides a basis for more informed decision making regarding processes which can be ignored during the collection of traditional LCA data. This paper proposes a hybrid LCA method for construction in which national input-output data fill those 'gaps' not accounted for by traditional LCA data. Regardless of the level of detail at which data are collected, LCAs can now be performed at similar overall levels of framework completeness.