Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.1

Inquiry

Facts collected to date: 1. The Cool Roof Rating Council (CRRC) is the referenced document for this point in the LEED Reference Guide v2.0. 2. The CRRC does not identify the testing system used per each roofing system listed 3. I have been in discussion with one roofing company about a product listed in the CRRC with a 0.9 emmissivity. i have received a cut sheet on the product stating the emmissivity rating as 0.9. 4. Further investgation revealed that the test used was the ASTM C1371 not the ASTM E408. The roofing company states that the E408 is a more expensive test and with the same results, so most will use the C1371. 5. The CRRC states that the two tests "can produce results that differ from each other by 0.05." 6. This same discussion has been repeated with many of the roofing manufacturers, with the same results. Questions: 1. How critical is the use of the ASTM E408 rating test for emmisivity versus the ASTM C1371 test to obtain LEED approval of the roofing system used? 2. Is it enough to submit a cut sheet highlightng the 0.9 emmissivity for LEED compliance of this point?