A discussion on the BPDO-EPD forum (http://www.leeduser.com/comment/redirect/66396) has started me thinking about how to treat materials that could fall on a Credit tipping point depending on whether or not one classifies them as structure/enclosure.
For example, many projects spend a significant chunk of their budgets on gypsum board (drywall). Some percentage of the board forms part of the exterior wall and ceiling assembly, making it part of the “enclosure.” In many cases, the gypsum is there as fireproofing to make combustible load-bearing elements (such as wood frame) code-compliant. Some have argued that this makes it structural. Still, in most buildings, the lion’s share of the gypsum board is for non-structural work on the interior of the building. To count this portion as non-structure/non-enclosure, are we required to tally the costs and characteristics of the interior gypsum separately from the small percentage used to enclose the structure?
Wood framing raises a similar question. Some is used for exterior walls and interior bearing elements, but some comprises non-bearing interior partitions. The sticks of wood are identical, but it appears that we must track them separately.
Since, for Option 2, structure and enclosure materials may not constitute more than 30% of the value of compliant building products, all this hair-splitting may be necessary to maximize the contributions of non-structure/non-enclosure elements. I am curious how others have handled materials like these.
Paula Melton
Editorial DirectorBuildingGreen, Inc.
LEEDuser Expert
183 thumbs up
September 10, 2016 - 1:33 pm
Interested in how others will approach this, Jon. Seems like one strategy would be to use less structural material overall, which would dovetail nicely with whole-building life-cycle assessment. As I noted on the original version of this discussion, however, USGBC has publicly stated a "litmus test" that if it's in the structural drawings, it's structure. Perhaps an interpretation is needed to define this as well as what counts as enclosure.
Michelle Bombeck
Associate PrincipalO'Brien360
36 thumbs up
July 5, 2018 - 7:11 pm
Hi Paula -
In one of the threads you indicated that you were looking into getting some clarification from GBCI on this question. Were you able to get any clarification from them, aside from the 'litmus test'?
Michelle Bombeck
Associate PrincipalO'Brien360
36 thumbs up
July 5, 2018 - 7:20 pm
Also, I saw the interpretation regarding the revised allowable % of structural materials (https://www.usgbc.org/leedaddenda/100002183) but it's not clear to me what 'significant' amounts of enclosure would be. Thoughts on that?
Martha Norbeck
PresidentC-Wise Design and Consulting
71 thumbs up
September 30, 2018 - 12:09 pm
Are teams achieving this point? Because if this structure and enclosure limit, we're maxing out in the high teens. I get that the goal is to raise the bar, but setting it too high also causes problems with convincing owners to proceed with LEED at all.
Dionisio Franca
DirectorWoonerf Inc.
30 thumbs up
September 30, 2018 - 9:28 pm
Hi Michelle,
I read "significant amounts" as any amount over 30%. Let's say you are working on a building that the costs of the structure and enclosure are 50% of the total costs. In this project, the cap would be 50% instead of 30%.
Hi Martha,
We agree with you that this credit is too hard to achieve. Most BPDO credits are...