Assemblies

David - An assembly in LEED terms is "product formulated from multiple materials (e.g., a composite wood panel) or a product made up of subcomponents (e.g., a window system)." So your other product composed of aluminum and glass is also an assembly. Assemblies are a bit tricky to calculate and it is unfortunate your LEED consultant is not willing to provide you with the details on what they are and how to calculate them. Recycled content value for an assembly is determined by weight. In addition to the post- and/or pre-consumer recycled content for each component, you'll need the weight of each component (steel, glass, and aluminum) as well as the overall weight of the entire assembly. You also need the cost that you are charging to the general contractor for the product.

Check out the Sample Assembly Calculation worksheet in the Recycled Content Calculator under the documentation toolkit for this credit. The percentages in the %Material/component represents of total product are based on their weight. Hope this helps!

David—Michelle is right. Calculating assemblies is tricky. However, figuring out whether you have an assembly is easier. To put it simply, ask yourself, “What gets delivered to the site?”

For example, if a glass railing system consists of steel framing, aluminum trim, and tempered glass infill panels, and if the parts ship separately, coming together only when they are installed onsite, the system is not an assembly. You would report the costs and the recycled percentages of each component separately.

By contrast, a prefabricated window unit would be an assembly. You would calculate the assembly’s composition as Michelle describes, using the weights of its various components, and report one cost for the whole shebang.

In either case, the costs that you report should include taxes, shipping, and all other expenses incurred prior to delivery (such as off-site fabrication costs). Leave out costs incurred onsite (such as installation equipment & labor).

Are those terms idiot enough?

For a less simplistic look at assemblies, see the underlying logic outlined in a more recent discussion:
http://www.leeduser.com/comment/redirect/64277.

This may be quite a silly comment but if one shall account for the connectors in an assembly like glass railing systems should one also account for the collective screws/nails/metal pegs/glue for an assembly like plastic laminate casework or wood cabinetry. (I can understand the hardware being counted as a relevant material) It seems overly-meticulous to qualify a wood or p. lam cabinet as an assembly because it is nailed or glued together at delivery. Should one account for the <1% by weight as the nails or screws or am I being inordinately exact? Thank you

Matt—It’s not a silly comment at all. You’re just figuring out that you don’t really have to track down everything to document the MR credits. Think about it…millions of components can go into a single building, but counting them all up is unnecessarily finicky. Fortunately, the MR credits are weighted by cost. By focusing first on the products and assemblies that you spend the most money on, you can weed out tiny bits and pieces.

For example, a project with a steel structure spends a large chunk of its budget on steel assemblies. The makers of heavy steel members can often provide detailed MRc4 data reporting high recycled content, but the lightweight odds and ends are often harder to track down and contribute far less to the credit. I work hard to get the most complete MRc4 data for my major steel assemblies, then I work my way down through the materials budget tracking MR credit contributions for all the big-dollar items.

By the time I get to glass railing systems (as in the example above), I may have secured my MRc4 credits, but just to be safe, I may go ahead and track the recycled content in the system. Again, for this assembly, I start with the heaviest components that have the highest recycled content. All I care about is the assembly’s total cost, it’s total weight, the weights of the heavy hitters, and their respective recycled percentages. I just figure the balance of the “other” components at 0% recycled without figuring the individual weights of each one.

Finally, to your cabinetry example: the hardware’s MRc4 contribution is probably negligible, but if you use certified wood for MRc7, the assembly calculations are the standard documentation that an FSC-certified fabricator should know how to provide.