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
-glazing
-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?)