Rating System

LEED BD+C: New Construction, LEED O+M: Existing Buildings, LEED BD+C: Core and Shell, LEED BD+C: Schools

Rating System Version

v3 - LEED 2009, v3 - LEED 2008, v2 - Schools 2007, v2 - LEED 2.2, v2 - LEED 2.0

Inquiry

Previous CIRs have allowed the use of a weighted average approach for the reflectance and for the emissivity of a roof material. A baseline reflectance is calculated by applying the minimum reflectance of the roof (0.65) and multiplying it by the percentage of roof it covers (75%). This calculation results in a baseline reflectance of 0.4875. Similarly, baseline emissivity can be calculated as 0.90 x 75% = 0.675. Can this weighted average approach be used for both of these values simultaneously? In other words, if a roof material covers 100% of the roof area, and its reflectance is 0.4875 or greater, and its emissivity is 0.675 or greater, does it meet the credit requirements? Will the weighted average approach also be allowed as it pertains to a roof\'s SRI under v2.2?