I’m exploring the Whole-Building Life-Cycle Assessment (WBLCA) methodologies defined by the LEED and Level(s) frameworks, and I’m curious about understanding the specific differences in the scope and calculation method for the following environmental impact indicators:
a) Depletion of Nonrenewable Energy (MJ) according to ISO 14040 & ISO 14044 (CML 2002, November 2012), as required by LEED;
b) Abiotic Depletion Potential (ADP – fossil) for Fossil Resources (MJ) according to EN 15804 & EN 15978, as required by Level(s).
Hi @Alice, @Steven, I’m comparing baseline and design and the ozone depletion is +20% and all other impact categories show reductions. Concrete floors and slabs are the culprit, however, I’ve tried swapping many different types of mixes FA/SL, etc. and cannot understand what is driving the ozone impacts. They seem all over the place. What should I look for in concrete mixes (4000 psi) that will reduce the ozone depletion?? Does it have anything to do with the grid mix? Transportation? Reinforcement?
Hi Kai! Ozone impacts can be tricky and even a single data point can have a negative effect. Ozone emissions are tiny compared to, say, Global Warming Potential, or even Acidification and eutrophication. Sometimes the difference comes down to how one manufacturer models their EPD versus another. While the “big” impacts usually stem from materials, I can’t say for sure in your case without seeing your project. Could you send it over in a Private Message (or contact support) so we can take a look and give you the right recommendation?
A recent LCA for LEEDv4.1 shows a significant increase in Eutrophication when all other indicators are down and I’m trying to pinpoint the contributors.
I want to identify the material contributing most to the Eutrophication, how do I do that?
Is the Category Section Share the amount of kg Ne between the baseline compared to the proposed? Or do I need to compare the baseline and proposed results to determine the relative change?
Is the higher percentage indicate these are the most contributing materials?
6000 psi Ready-mix concrete
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I’m confused why Indicators like GWP have high percentages in the proposed Section Shares in red but there is a reduction in the indicator.
You would indeed first use the comparison feature, if you there see that there’s an increase in specifically EP emissions then you should go into your improved design to pin-point exactly what are the big emitters.
The ‘most contributing materials’ list focuses on GWP only, so you’ll need to dive into the details of your EP emissions instead.
Often this would be in your A1-A3 (unless the material is replaced often, as it would then also be present in B4-B5).
Click on details, while on the results page. In the design that has the increase in emissions (often would be the ‘improved design’).
In your top heading you could also show the numbers, and see the actual calculation, the percentage display however, should already tell you which product contributes the most. Usually its related to the production process, and these emissions can differ also between manufacturers.
For the specific materials you highlighted, I can’t really say without checking your specific project. They might as well be big emitters because of additives or construction processes.
Hope this helps, let me know if you want me to check a specific project.
Thanks Steven. Could you please look at the EP big hitter in the proposed scenario for Converge HQ? Your instructions were clear, but I’m unsure if the red numbers are comparative or reflect the proposed only. For example, the baseline results have different numbers in red. I’m unclear if I need to compare the red numbers in both reports to determine which material are most contributing.
I’ve reviewed a copy of your design to avoid altering your results. Your EP emissions are indeed 21% higher than the baseline. Just a note on the interface: the “Red” numbers in the comparison view are comparative, while the percentages within a single design reflect the breakdown of that specific design only.
In the proposed design, 90.26% of EP emissions originate from the foundation & substructure. The materials you highlighted are the primary contributors:
Steel: Accounts for 28.27% of total EP emissions.
Concrete (6000 psi): These mixes account for 55.51% of total EP, with other psi mixes also adding significant impact.
It would be helpful to verify the mix used for your baseline. Looking at your proposed design, the manufacturer-specific 6000 psi mix you selected has a higher EP emission profile than the 2022 industry average.
Given the scale of the project, tens of thousands of cubic yards, this choice significantly drives the increase in EP emissions. It may be worth exploring alternative 6000 psi mixes for the baseline (if you have used the 2022, there are newer profiles averaged available too) or discussing the rationale for these specific selections with the LEED assessor.
