The intent of this credit is to reduce heat islands to minimize impact on microclimate and human and wildlife habitat. To meet the requirements of this credit we plan to use light-colored/high-albedo materials for a minimum of 30% of the site\'s non-roof impervious surfaces. We have approximately 62,000 SF of white colored gravel driveways on the site, 80,000 SF of asphalt and 38,000 SF of concrete. We have received documentation from the American Concrete Pavement Association stating that new gray portland cement concrete has a reflectivity between 0.35 and 0.40, which meets the requirements of this credit. Aged gray portland cement has a reflectivity between 0.20 and 0.30. Will we be able to use the documentation from the American Concrete Pavement Association as a sufficient source to show compliance with this credit? Also, will we be able to use the reflectivity ranges for new gray portland cement to fulfill the requirements of this credit? We know that black asphalt will not meet the requirements of this credit. We are unable to obtain documentation from the company supplying the gravel on its reflectivity value. We have tried to borrow or purchase a spectrophotometer to measure the reflectivity of the rocks on our own, but have not found an affordable option. We have also tried to find a federal standard on the reflectivity values of different colors and have been unsuccessful. If the rocks are essentially white, will that be enough of an explanation to factor the rocks into the calculation to comply with the requirements for this credit?
Credit 7.1 requires the use of "light colored/high albedo materials (reflectance of at least 0.3) for 30% of the site\'s non-roof impervious surfaces." Reflectance level of applicable materials must be adequately documented to earn this credit.Include reflectance documentation from the American Concrete Paving Association, making sure to indicate the original source of the research data and the reflectivity category that relates to your concrete mix, coupled with a site plan showing where concrete will be used. Alternatively, testing labs can be found using the ASTM lab directory at www.astm.org. Testing fees should be approximately $200 for ASTM E903.For the concrete portion of the site, it is acceptable to use the reflectivity rate for new concrete on this credit, as this will meet the intent of the credit at the time of construction. Existing old concrete can not be considered in the square footage for high-albedo materials, unless its reflectance can be measured to be 0.3 or greater, and documentation is provided showing this reflectance.For the gravel portion of the site, simply listing the gravel as white is not sufficient to meet this requirement. As stated in the credit description, it is necessary to provide the documentation indicating the reflectance of the gravel as meeting the 0.3 minimum requirement. The project can refer to the Lawrence Berkeley Labs website, http://eande.lbl.gov/coolroof/membrane as a reference source for the reflectivity of white gravel. The use of white gravel should be distinguished from white-coated gravel, which is not suitable for use in parking and driving applications. Applicable Internationally.