Evaluating metals

Hi Heather, We actually have a big lesson learned from a current project, where comparing anodized vs. PVDF painted aluminum extrusions yielded a 1.5% reduction in embodied emissions over the whole building. GWP of anodized was around 38% of PVDF. This is big in my view -- this wasn't changing the metal itself but just the finish. There was a slight upcharge for anodized over PVDF, but I don't know if that would always be the case. Note that this was for extrusions. We also looked at aluminum panel finish but there are very few aluminum panel EPDs available and none distinguish between PVDF vs. anodized finish, unlike aluminum extrusions where we do have 2 EPDs that show a big difference.  This same study compared GRFC, Zinc, Aluminum, and Precast wall panels. We went with GFRC for aesthetic reasons, although zinc and alumnimum were both around half the GWP of GFRC or Precast. Regards, Brad Jacobson EHDD

There are  multiple issues with zinc sheet and zinc coatings (galvanizing) for stormwater runoff issues. We did  extensive research into stormwater remediation on a project to bind the zinc runoff, but would definitely be a big part of the consideration before using again.  Extraction and mining practices for bauxite and zinc are another factor.    Rich , Mithun