Hi All,
We get a lot of concrete mixes that have reduced carbon footprint, however we're not able to use that for LEED because they dont have EPDs. I was wondering if LEED with accept the concrete mix results (GWP + other environmental impacts) from calculators like ZGF calculator or a custom in-house tool? I know Tally creates custom mixes, but the information is outdated since it still uses NRMCA 2019 concrete benchmarks. Other tools like the NRMCA Concrete Calculator doesnt include other environmental impacts.
Let me know your thoughts.
Robert Frost
April 9, 2025 - 4:54 am
nice
Chris Flint Chatto
PrincipalZGF Architects
10 thumbs up
May 8, 2025 - 3:27 pm
Hi -
I co-created the ZGF concrete tool. To be clear, it is really a standalone Tally-based concrete LCA calculator. it allows you to input the specific custom mix you get from a supplier, and compares it the NRMCA regional average mix for that strengthm using the Tally Gabi database to analyze the environemtnal impact of the constituent materials for both. The newest version of our calculator compares to the 2022 NRMCA report of regional average typical mixes.
So, we haven't used the calculator directly for LEED documentation (but originaly developed it to do iterative concrete LCA analysis to support a LEED Tally model). But, I would be surprised if LEED didnt' allow you to use the most recent version of Tally. I would think LEED would accept the most recent version of Tally. That said, even better and more accurate (but less savings), compare your actual mixes to another custom mix, which is composed of the constituents of the NRMCA 2022 regional mix for that strength.