Embodied Carbon Tool Database Comparison Report

Author/Contributor: Priopta

Alberta Context: This resource compares embodied carbon tools used across North America. Although embodied carbon tools are not specific to Alberta, the tools themselves are not region-specific.

Summary: 

This report, funded by the NRC, addresses the need for confidence in Whole Building Life Cycle Assessment (WBLCA) results as embodied carbon requirements increase across Canadian initiatives.

The Embodied Carbon Tool Database Comparison analyzes five leading tools (One Click LCA, Athena, Tally, EC3, and BEAM) and details how databases and default assumptions lead to differences in results, even when quantities are identical. Variations are traced to identifiable drivers, including differences in product-stage impacts (A1–A3) (e.g., EPD-based vs. generic LCI), downstream assumptions like transport (A4), construction waste (A5), service life (B4), and end-of-life (C1–C4), and inconsistencies in biogenic carbon and non-GWP impacts. The analysis also compares the depth of data coverage across tools.

Intended as a neutral and technical comparison, the report documents alignment and divergence among these independently developed tools to provide an evidence base for coordinated improvement. The findings can inform future efforts to define consistent national baselines and default modelling assumptions for Canadian projects, standardizing modelling from A4 through C. This will reduce variability, strengthen comparability for benchmarking, and support credible policy implementation in Canada and potentially other regions.

The report is for WBLCA practitioners, policymakers, standards bodies, tool providers, benchmarking teams, manufacturers, and EPD stakeholders seeking a clearer view of tool output alignment and divergence for better comparability, benchmarking, and target-setting.