LCA models in building industry practice - how do practitioners’ assumptions affect LCA results?

This study exemplifies uncertainties in Life Cycle Assessments (LCA) by investigating the results of nine building LCAs made by nine LCA practitioners. The study compares material quantities and Global Warming Potential (GWP) results of the nine LCAs before and after a review process. From the building LCAs before review, we identify several errors that significantly influence material quantities and GWP results. After correcting the errors, we still see notable differences in the material quantities and LCA results from the nine LCAs. The study proves a need for conducting thorough reviews to eliminate the most prominent errors in building LCAs and a need for uncertainty assessment as a standard practice.