Enclosure scope : what to include? what EPDs are out there?

I am starting to conduct more LCAs that include enclosure materials and would like to know 1)what people include/don’t include in their material take-off, 2) what EPDs they use for benchmarking in OneClick or EC3

Correct me, but I don’t think LEED v4.1 has any guidance on what is to be included as part of enclosure. The mid-cycle CALGreen code update will include enclosure and says “shall be limited to glazing assemblies, insulation and exterior finishes”.

I am a structural engineer and will do the structural take-offs and then we ask the architects to quantify the enclosure materials since they are more familiar with all the bits and bobs that go into an assembly. I take all the information and conduct the LCA; either combine both structure and enclosure in one analysis or separate it out). In my experience we generally have collected the quantity of the following (either by volume or weight):

-mullions/metal extrusions
-insulation (both wall and roof)
-vapor/air/water barrier/membrane
-metal studs
-precast concrete panels
-metal panel
-gyp (interior and exterior rated)
-roofing material

1) Is that too detailed/not detailed enough? What do you include or not include?
2) Are there industry average EPDs to use as benchmarks? We use OneClick to conduct LCAs, do you have go-to EPDs you use as industry averages? I use EC3 as a reference but they don’t have vapor/air/water barrier (or do they?)

I like the diagrams from the Kaleidoscope tool which help visualise what is typically included. It is worth mentioning that if there is a wall cavity structure I will include the insulation, which the Kaleidoscope tool doesn’t specifically state. Kaleidoscope: Embodied Carbon Design Tool - Payette

When I select “typical” data I either try to use generic industry average EPDs, or an EPD of a commonly chosen product. So for air barriers I go for Tyvek Commercial Wrap because it is so ubiquitous. The EPD in One Click is: Air and water barrier system, mechanically fastened, 0.0451 lbs/ft2, 0.22 kg/m2, Tyvek (DuPont)

Hope that helps,

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