This research aims to contribute to quantifying whole building life cycle assessment using various software tools to determine how they can aid the construction industry in reducing carbon emissions, and in particular embodied emissions, through analysis and reporting. The conducted research seeks to examine and compare three whole building life cycle assessment
tools; Athena Impact Estimator, Tally and One-Click LCA to relate the input variability to the outputs of the three programs. The three whole building life-cycle assessments were conducted using a case study building with an identical bill of materials and compared to determine the applicability and strengths of one program over another. The research confirmed that the three programs output significantly different results given the variability in scope, allowable program inputs and generated “black-box” back-end calculations, where the outputted whole building life cycle carbon equivalents of One-Click LCA is less than half than of Tally meaning the programs outputs cannot be simply compared side-by-side.