Employ Building Materials and Practices to Reduce Heat Islands

B9Employ Building Materials and Practices to Reduce Heat Islands

1 point possible

Why this matters to the lake?

On a hot, sunny day, roof and pavement surface temperatures can be 50–90°F hotter than the air, while shaded or moist surfaces remain close to air temperatures. These hot surfaces, particularly during the summer, create heat islands, which can have negative impacts on water quality in the lake. Hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as runoff is released into streams, rivers, ponds, and lakes. Increased water temperatures lead to a decrease in diversity in aquatic life and promote algal growth.


  • Preserve water quality by reducing thermal impacts, protecting aquatic habitat and diversity
  • Protect the environment and improve communities through the use of sustainable building materials


  • One point is awarded for meeting any of the following requirements:
    • Provide shade (within 5 years of building) and/or use light-colored materials and/or open grid pavement for at least 30% of the site’s non-roof impervious surfaces.
    • Place a minimum of 50% of parking spaces underground.
    • Use an open grid-pavement  system for a minimum of 50% of the parking area.
    • For roofs, use Energy Star-compliant and high emissivity roofing for a minimum of 75% of the roof area.
    • Install a vegetated roof over at least 50% of the roof area.


Include the following information with application:

  • As part of the Proposed Site Plan, show which requirement is met and provide the appropriate calculations of the percentage of building materials used that reduce heat islands. 

Other Resources