In LEEDv4, Options 2 of MRc2 & MRc3 and Option 3 of MRc4 all include a rule that "Structure and enclosure materials may not constitute more than 30% of the value of compliant building products." How will that be calculated?

For example, in MRc3 Option 2, the Credit threshold is 25% of the total cost of permanently installed building products. It appears that compliant structure/enclosure could only contribute up to 7.5% (30% x 25%) toward Option 2. The remaining 17.5% would have to come from compliant interior/finish/nonstructural components. Is this interpretation correct?

How does the “Regional Multiplier” figure in to the 30% rule? Does the structure/enclosure limit stay at 7.5%, or can we use regional sourcing to double the amount of structure/enclosure value that we can count toward the MRc3 threshold (say, from 7.5% to 15%)? If the latter is correct, only 10% would need to come from compliant interior/finish/nonstructural components.

As suggested above, the order of the calculation makes a big difference when targeting materials for these credits. The new requirements shift the focus away from structure and toward interior finishes, but having not seen the new Reference Guide, it is not yet clear just how much.

Any insights?