Calculating MRc4 - Recycable Material Credits

Richard—For Materials and Resources Credits MRc3 through MRc7, the Reference Guide states, “Materials costs include all expenses to deliver the material to the project site. Materials costs should account for all taxes and transportation costs incurred by the contractor but exclude cost for labor and equipment once the material has been delivered to the site.” It also says, “Include only materials permanently installed in the project” in the calculations for Credits MRc3 through MRc6.

. .1. Since steel fabrication occurs before delivery of the material to the site, include the fabrication cost when calculating material cost. (This usually requires treating the fabricated steel as an “assembly” when calculating its credit contribution.)

. . 2. Exclude the cost of placing and finishing cast-in-place concrete, as this occurs after the concrete’s delivery. Also exclude the costs of formwork, shoring, scaffolding, screeds and other equipment and temporary materials used during the installation. Concrete and the steel are usually purchased and delivered separately, so you can usually calculate their costs and credit contributions separately. Cement is a component of concrete, so it would be part of the “assembly” calculation for concrete. (On the other hand, since precast concrete is fabricated elsewhere, the concrete, rebar, and fabrication costs would all be included in the material cost.)

. . 3. For gypsum board systems that are assembled on-site, you would calculate the costs and contributions of the gypsum board separately from the framing, the fasteners, the accessories, and the finishing materials, excluding the costs of installation (labor and equipment).

These rules of thumb apply whether you are calculating recycled content, regional materials, rapidly renewable materials, or material reuse. The calculations for certified wood (MRc7) are similar, but with a few nuanced variations.

Tire Work https://earthship360.com/tire-work/
Structural, Bearing and Retaining Walls made with rammed earth encased in recycled steel-belted rubber tires.
- Very strong, Economical, Local, Sustainable. -
The major structural building component is recycled automobile tires filled with compacted earth to form a rammed earth brick encased in steel belted rubber. This brick and the resulting bearing walls it forms is virtually indestructible.

My feelings about Earthships aside, this post is not appropriate here. Part of what makes LEEDUser so great is the focused discussion about particular LEED issues/questions. This spam does not belong here. Jon, are your monitoring this page, and if so can you please see about removing this? Thank you very much, and sorry to be forum police, just want to keep the integrity.

apologies. I figured this was relevant given the topic of the thread... recycled materials.

Lyle—These last 3 posts came through just as I was leaving town for Greenbuild. I am back, so I can respond.

I agree that the Earthship post seems to promote one particular technology without addressing how that system fits into LEED MR credit calculations, which is, after all, the topic of this forum and of this discussion thread. Even thought the post seems out-of-place, I cannot remove it from this forum. Instead, I will try to bring this thread back on-track with Richard’s original post by discussing how such a system would figure into NC-2009 MR Credits.

In LEED-2009, Materials and Resources Credits MRc3 through MRc7 calculate the costs and contributions of materials normally specified in Divisions 03 through 10 of CSI MasterFormat 2004 and in a few sections in Divisions 31 and 32.

The Earthship post describes rammed earth construction, which MasterFormat 2004 does not address anywhere. Newer versions of MasterFormat (LEEDv4 uses 2012) classify Rammed Earth in Division 13 Special Construction, which lies outside of the Scope of the MR credits.

While at Greenbuild, I had an opportunity to sit down with a LEED Reviewer the GBCI Certification Work Zone. He noted that using old tires in rammed earth walls seemed entirely within the intent of the MR credits, but that, since MasterFormat does not address this construction type in the appropriate Divisions, project teams should request a formal interpretation from USGBC before attempting to include such materials in MR Credit calculations.

The same would go for other alternative technologies addressed outside the prescribed MasterFormat Sections, such as straw-bale construction, tensile structures, and modular prefabrication.

The earlier post describes a system with two major components—old tires and earth—brought together through hand labor.

As noted previously, the onsite labor of assembling the walls and compacting the earth into the tires is excluded from the calculation. Earth gathered onsite has no “cost,” so it does not figure into the MR credits. All that remains are the tires.

It appears that the tires would be purchased, gathered, or donated and incorporated into the construction without any kind of alteration or remanufacture. Such materials do not meet the MRc4 definition of “recycled materials.” Instead, they might qualify as reused or salvaged material under Material Reuse Credit MRc3. For guidance on determining the “cost” of such materials, see http://www.leeduser.com/credit/NC-2009/MRc3.

There! I hope that we are back on-topic. Please note in LEEDv4 evaluates MR credits using a wider range of criteria. This thread only addresses LEED-2009.