Embodied Carbon & MEP

Hi all, thank you all for the comments on my MEP post on Basecamp. As we are transitioning to this new platform, I am sharing it again.

Anyone with an expertise in embodied carbon at MEP (Mechanical, Electrical, Plumbing) product and system level?
We are building expertise and research on this subject at Integral Group but would like to engage with other experts around the world for more positive impact.

With our first research projects, we have found that MEP can have a huge impact. See below, a study we did looking at all embodied carbon emissions from an office retrofit in SF including all MEP elements - published in CIBSE journal. The study shows for instance that MEP are responsible for 50% of all embodied carbon emissions in worst case scenario, with 18% associated with refrigerants leakage only!

If you have some useful resources, know experts, please reach out. We believe Engineers need to look at embodied carbon as well - no longer just operational. Maybe we could start a focus group on this topic.

Link to the study: https://www.cibsejournal.com/general/getting-to-grips-with-whole-life-carbon/

Louise Hamot



Hi Jordan, I am responding to your questions from Basecamp here concerning the study:

  • were recycling benefits counted for the materials being removed and recycled during retrofit?
    No, Module D is not included indeed
  • In figure 4, is the “building embodied carbon” include all existing and new materials, or just the additional building materials used in retrofit?
    Just the additional materials for the retrofit
  • In figure 4, how many times were the PVs replaced over 30 years?
    It was assumed to be replaced once (20 year lifetime) and efficiency depreciation has been accounted as well
  • I think your y-axis units in Figure 2 is mislabeled. Or…I hope it’s mislabled - because that’s a lot of CO2!
    The units are unfortunately right - it is kgCO2e
  • How big is this building?
    the area is about 2,000 m2

Thank you for your positive feedback, feel free to ask more questions.

Thanks @louise.hamot! I’ll ping Barbara Rodriguez to get her active in this group discussion. She just completed her PhD on this topic building from her work with the Carbon Leadership Forum-with documentation posted online on our site.


Louise and others interested in EC,

We have also been looking into the embodied carbon of MEP following our study with the Carbon Leadership Forum (thank you @ksimonen, @myth29, and Barbara Rodriguez!), which highlighted HVAC and Lighting as two of our hot spots.

I would love to connect with others in the network also working towards embodied carbon solutions for lighting and HVAC.


Your thought about considering embodied energy for MEP resonates, Louise. As a contractor, I have been alarmed when my estimating software tells me the weight of the materials we install, then extrapolated that measure to the embodied carbon it represents. To date I have had no conversation with any engineer that this needs to be a topic of discussion, I think because operational energy has been our primary target for reduction for so long. Respect to the building pros discussing it architecturally and structurally, MEP can catch up. There is a shortage of easy metrication for MEP materials to inform such decisions, would you agree that would be a first step?

Hi John, thank you for your response. Our firm which includes building services engineers, are trying indeed to get to a whole life carbon approach rather than just operational as we used to. We are working to come up with rules of thumb and easy metrication and we are trying to bring along Institutions (working with CIBSE) - but it is long process and data is scarce. Would be interested to know more about weight and emissions concerning A5 and end of life concerning MEP - maybe we could start a discussion?

Thanks so much for clarifying!

John, this is interesting. In the MEP studies we had difficulty getting actual material quantities for MEP systems. Where are you getting the weight data?

I’m working with MEP design/build firms to gather this data, too, and from there, calculate the embodied carbon of material quantities.
Gathering material weight and quantity hasn’t been that difficult for these firms, either through a Revit model or from their material take-offs for purchase and pricing. Is this your experience, too?
I’ll attach my first study in this thread soon!

Kate, Kelsey -

Our estimating software gives us the total weight for the commodity items that we use in MEP. It is interesting to note that in urban areas, weight does not play a critical role in cost and availability of material, except for sheet metal. Having talked with contractors that build in remote northern communities, I learned that weight was a critical factor in their material choices because of shipping costs, not a thought I have ever had to contemplate in Toronto, Ontario. But after talking with them, I remember realizing we buy food by the pound, but not MEP products, without having a great explanation for why when you consider that both are value added products distributed widely. And participating in IPD contracts where embodied carbon mattered has made me appreciate that the MEP community needs to catch up to the architectural community, not only focussing on energy consumption, although of course that remains critical too.

Happy to amalgamate data from my contracts and contribute to a database that anyone might want to build to conduct quantitative analyze that could help us inform better choices. Recently did enough study myself to realize that although I dislike PVC, good quality PVC pipe and fittings are a better life cycle cost than cast iron soil pipe, my personal preference. That’s the kind of data I’d love to have for all our systemic choices.

Hi John, would love to have information about quantities. We are doing analyses from our Revit models but it doesn’t mean it will match what is actually going to be installed exactly on site. FYI - we are currently doing research on the overall subject to come up with resilient rules of thumb for early design decision making.

Cool! I’m tagging @BxRD Barbara Rodriguez. Would be great to see how your data could integrate in the database she developed for her dissertation.

Louise, we’re also looking for the installed material quantities, so we can factor in waste, and look to possible material savings in prefabrication processes of systems.
Have you been gathering any of this data and seeing how much waste is a factor?
I would think most contractors are already minimizing this, to improve their margins…