ID#2643 made on
SSc7.1 - Heat island effect - non-roof
LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Core and Shell, LEED O+M: Existing Buildings
This Credit Interpretation Request is for LEED-EB Sustainable Site Credit 6.1 Heat Island Effect, Non-Roof. The intent of the Credit is to reduce heat islands and minimize impact on microclimate, huma...
This Credit Interpretation Request is for LEED-EB Sustainable Site Credit 6.1 Heat Island Effect, Non-Roof. The intent of the Credit is to reduce heat islands and minimize impact on microclimate, human habitat and wildlife habitat. The Credit can be achieved by providing a reduction in heat island effects caused by dark paved surfaces typically used in construction. There are four options (Options A, B, C & D) available that can be used to achieve the Credit. Although each option is based on a unique method of reducing heat island impacts (tree shading, high-albedo pavements, covered parking, and open grid pavement), none of the options allow for the combined benefits from these various methods of reducing heat island effects. Since these options represent unique methods of providing a reduction in heat island effects, a combination of these methods using more than one option can satisfy the intent of the Credit, and may provide more benefits than can be achieved by satisfying just one of the options. Our proposed method of achieving the credit utilizes high-albedo pavement (Option B), and underground / covered parking spaces (Option C), which are distinct areas that are not redundant. Not included in our approach is the tree shading provided throughout the site, which may further contribute to the reduction of heat island effects. The following calculations for Option B and Option C demonstrate how the combined benefits of high-albedo pavement and covered parking exceed the intent of the Credit. Option B - High-Albedo Pavement There is 179,303 SF of high-albedo concrete pavement on-site having a reflectance of 0.3 or greater. The total amount of non-roof impervious area is 912,560 SF. The percentage of high-albedo pavement is (179,303SF/912,560 SF) = 19.65%. Although this percentage is less than the 30% required to satisfy this Credit if used alone, it contributes significantly to the reduction of heat island effects, and should be counted as a contributing factor to satisfying the Credit. By using the ratio of the benefits achieved to the benefits required, this option satisfies (19.65%/30%) = 65.5% of the requirement. Option C - Underground Parking On the site there are 490 parking spaces underground. The total amount of parking spaces on site is 2075. The percentage of underground parking spaces is (490/2075) = 23.61% Although this percentage is less than the 50% required to satisfy this Credit if used alone, it contributes significantly to the reduction of heat island effects, and should be counted as a contributing factor to satisfying the Credit. By using the ratio of the benefits achieved to the benefits required, this option satisfies (23.61%/50%) = 47.2% of the requirement. Combined Options B & C The high albedo pavements on the site satisfy 65.5% of the requirements for Option B. The underground parking spaces on site satisfy 47.2% of the requirements for Option C. These two elements of the site contribute separately to heat island effects, and in this case these two elements are not redundant or overlapping. Therefore, working together these two options when combined create a reduction in heat island effects greater than reaching 100% satisfaction for just one of the options. The combined benefit that contributes to the reduction of heat island effects is 65.5% + 47.2% = 112.7%. Therefore, the intent of the Credit is satisfied, and the project should qualify for the Credit.
The combined Credit Option approach and calculation methodology outlined above satisfy the intent of LEED-EBv2.0 SSc6.1 and would be an acceptable compliance path for earning this credit as long as there were no redundancies or correlations in project site surface area between the combined SSc6.1 Option submittals. For example, Option B High albedo pavements and Option C underground parking spaces could be combined to meet the combined 100% percent compliance level requirement. However, it would not be acceptable to count Option A shading and Option B high albedo surface area as compliant for both SSc6.1 Options if they covered the same surface area. Similarly, Option D open-grid pavement surface areas consisting of Option B High albedo pavement material would not be able to be counted twice for the same surface area. If these Options covered different surface areas of the site, then it would be acceptable to count these areas as compliant for both Options. Applicable Internationally.
Related Addenda (Corrections & Interpretations)