Structure and enclosure

Noriko—The definitions are in the LEEDv4 Glossary (http://www.usgbc.org/resources/leed-v4-glossary-terms-translations):

Structure: Elements carrying either vertical or horizontal loads (e.g., walls, roofs, and floors) that are considered structurally sound and nonhazardous.

Enclosure: The exterior plus semi-exterior portions of the building. Exterior consists of the elements of a building that separate conditioned spaces from the outside (i.e., the wall assembly). Semi-exterior consists of the elements of a building that separate conditioned space from unconditioned space or that encloses semi-heated space through which thermal energy may be transferred to or from the exterior or conditioned or unconditioned spaces (e.g., attic, crawl space, basement).

Thanks, Jon!

I'm not sure Jon fully answered Noriko's question. In my humble opinion, fireproofing paint (mastic?) on the steel, would be considered part of structure, because it's there to make the steel structure compliant with the building code construction type; and the waterproofing would be part of enclosure because it's a component of the assembly designed to keep the elements out. Again, just my opinion, but that's the argument I would use.

Thanks, David! I'm trying to get an answer from USGBC.

Apparently there hasn't been an official interpretation yet, but Sara Cederberg replied:

My litmus test has been, if it’s on the structural drawings, its structure.  So no, I wouldn’t include fireproofing as structure.

I would agree with David that I did not fully answer Noriko’s question. I hoped that, by linking her to the glossary, I could help her reach her own conclusion based on the specifics of her particular project. I would also agree, based on the definitions, that waterproofing is part of the envelope, and that fireproofing could go either way. (I have even debated the question with a structural engineer who argued that fireproofing was completely outside his scope.)

In the end, questions like this only matter for products that fall on a Credit tipping point. If this were the case on one of my projects, I would err conservatively or ask USGBC for a credit interpretation.

Paula/Noriko/David/Sara: This discussion has started me thinking about how to treat materials that one could classify as structure/enclosure, or not, and that could fall on a Credit tipping point.

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. Using David’s rationale, 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.

Since the questions above are applicable to all BPDO Credits, I have posted them to the “Sourcing of Raw Materials” forum. Let’s continue this discussion there: http://www.leeduser.com/comment/redirect/66653.

I have a similar question, for the structure and enclosure, in this case the window frames and door frames do not count, correct?