Heat island effect - nonroof

Intent

To reduce heat islands¹ to minimize impacts on microclimates and human and wildlife habitats.

Requirements

Option 1

Use any combination of the following strategies for 50% of the site hardscape (including roads, sidewalks, courtyards and parking lots):

• Provide shade from the existing tree canopy or within 5 years of landscape installation. Landscaping (trees)
  must be in place at the time of occupancy.
• Provide shade from structures covered by solar panels that produce energy used to offset some nonrenewable resource use.
• Provide shade from architectural devices or structures that have a solar reflectance index² (SRI) of at least 29.
• Use hardscape materials with an SRI of at least 29.
• Use an open-grid pavement system (at least 50% pervious).

OR

Option 2

Place a minimum of 50% of parking spaces under cover³. Any roof used to shade or cover parking must have an SRI of at least 29, be a vegetated green roof or be covered by solar panels that produce energy used to offset some nonrenewable resource use.

Summary of referenced standards

Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer [ASTM C1549 - 09]

This test method covers a technique for determining the solar reflectance of flat opaque materials in a laboratory or in the field using a commercial portable solar reflectometer.

Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers [ASTM C1371 - 04a(2010)e1]

This test method covers a technique for determination of the emittance of typical materials using a portable differential thermopile emissometer.