I wanted to share the Embodied Carbon Tool Database Comparison report I published last month, along with the recording of the presentation I gave yesterday on it.
If you’ve ever modelled the same building in two different LCA tools and gotten different results, you’re not alone. It’s a common frustration, and it raises a fundamental question: where do those discrepancies actually come from?
This report looks at the underlying databases and default modelling assumptions across five major tools used in North America: One Click LCA, EC3, Tally, Athena, and BEAM. The analysis includes:
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A1-A3 GWP and other environmental impact categories across a range of material categories
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Default modelling assumptions for transport to site (A4), construction waste (A5), service life and replacements (B4), and end-of-life pathways (C1-C4)
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Biogenic carbon modelling differences across tools
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Database coverage (# of datapoints) per material category across each tool
The work was funded by the National Research Council of Canada, so there is a Canadian focus, but the data analyzed in the study covers data in both Canada and the U.S. I expect the findings will be relevant to many practitioners across North America, and likely useful in other regions as well where there is growing interest in improving consistency and comparability in whole-building LCA results.
While discrepancies exist across tools, the report also points to a path forward: more consistent baseline definitions for A1-A3, and better alignment around default values for later life cycle stages (A4 to C). That kind of alignment could help strengthen confidence in WBLCA results for benchmarking, design decisions, and policy development.
Download Report:
Watch Presentation:
