To minimize effects on microclimates and human and wildlife habitats by reducing heat islands.
Option 1. Nonroof (1 point)
Use any combination of the following strategies for 50% of the nonroof site paving (including roads, sidewalks, courtyards, parking lots, parking structures, and driveways).
- Use the existing plant material or install plants that provide shade over the paving areas on the site within 10 years of plant material installation.
- Install and plant planters, either at grade or raised. Plant material cannot include artificial turf.
- Provide shade with structures covered by energy generation systems, such as solar thermal collectors , photovoltaics, and wind turbines, that produce energy used to offset some nonrenewable resource use.
- Provide shade with architectural devices or structures that have a three-year aged solar reflectance (SR) value of at least 0.28. If three-year aged value information is not available, use materials with an initial SR of at least 0.33 at installation,
- Provide shade with vegetated structures.
- Use paving materials with a three-year aged solar reflectance (SR) value of at least 0.28. If three-year aged value information is not available, use materials with an initial SR of at least 0.33 at installation.
- Use an open-grid pavement system (at least 50% unbound).
Option 2. High-reflectance and vegetated roofs (1 point)
Use roofing materials that have an SRI equal to or greater than the values in Table 1.Meet the three-year aged SRI value (if three-year aged value information is not available, use materials that meet the initial SRI value) for a minimum of 75% of the roof area of all new buildings within the project, or install a vegetated (“green”) roof for at least 75% of the roof area of all new buildings within the project. Combinations of SRI-compliant and vegetated roofs can be used, provided they satisfy the equation in Option 3.
Table 1. Minimum solar reflectance index value, by roof slope
|Slope||Initial SRI||OR||3-year aged SRI|
|Low-sloped roof||≤ 2:12||82||64|
|Steep-sloped roof||> 2:12||39||32|
Option 3. Mixed nonroof and roof measures (1 point)
Use any of the strategies listed under Options 1 and 2 that in combination meet the following criterion:
|Area of Nonroof Measures||Area of High-Reflectance Roof||Area of Vegetated Roof||Total Site Paving Area||Total Roof Area|
Alternatively, an SRI and SR weighted average approach may be used to calculate compliance.
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