It isn’t every day you get an update from USGBC that corrects something they did that just didn’t make sense. While that could apply to any number of LEED v4 credits, this one applies to MRc3, Sourcing of Raw Materials, Option 2. This is the credit that is most similar to LEED 2009, where you need 25% of materials by cost to be recycled, FSC certified, salvaged, etc. The kicker that was put into place was that structure and enclosure (you know, things like structural steel, metal decking, concrete, etc – all the things w/recycled content and high cost) could only account for 30% of the total.
30% – (of the 25% require for the point), could come from structure or enclosure OR – 7.5% of the total materials cost – from components that quite often make up a huge percentage of a project’s budget. That made it tough for a normal project. How about a core and shell project? Those projects are literally nothing but structure and enclosure! Chalk up another credit to the “available but not achievable” list on your scorecard.
But, with the July 1 2017 addendum, there’s been a glimmer of hope. USGBC has revised the language to account for this (somewhat), but allowing for an additional calculations.
“Structure and enclosure materials may not constitute more than 30% of the value of compliant building products. Projects with significant amounts of structural and enclosure materials may exceed the 30% limit by calculating an alternative structure and enclosure limit.
For projects with significant amounts of structure and enclosure materials, the following calculation can be made to determine an alternative limit for the percentage of value that structure and enclosure materials can contribute to credit achievement. Note: this option is only available for projects that use the actual materials cost method (not the default cost method) to determine total project material costs.
Alternative Structure and Enclosure limit = (value $ of total building materials that are structural or enclosure) [divided by] (total actual materials value $)
Use the results to replace the 30% contribution factor limit in determining compliance with the credit.
So – hypothetically speaking, if you had $1,000,000 of structure and enclosure, and a total materials cost of $2,000,000, you would be allowed $1,000,000 / $2,000,000 = 50% contribution limit factor.
It isn’t great – you’re forced to use actual material cost for everything, but it does give a glimmer of hope to core and shell projects trying to earn this credit.