Heat Island Effect: Roof

LEED 2.2 Requirements:

OPTION 1
Use roofing materials having a Solar Reflectance Index (SRI)* equal to or greater than the values in the table below for a minimum of 75% of the roof surface.

OPTION 2
Install a vegetated roof for at least 50% of the roof area.

OPTION 3
Install high albedo and vegetated roof surfaces that, in combination, meet the following criteria:

• (Area of SRI Roof / 0.75) + (Area of vegetated roof / 0.5) >= Total Roof Area
• For a Low-Sloped Roof with Slope = 2:12, the SRI = 78
• For a Steep-Sloped Roof with Slope > 2:12, the SRI = 29

*The Solar Reflectance Index (SRI) is a measure of the constructed surface's ability to reflect solar heat, as shown by a small temperature rise.  It is defined so that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100. To calculate the SRI for a given material, obtain the reflectance value and emittance value for the material. SRI is calculated according to ASTM E 1980. Reflectance is measured according to ASTM E 903, ASTM E 1918, or ASTM C 1549. Emittance is measured according to ASTM E 408 or ASTM C 1371.

Submittals (DESIGN):

Provide copies of the project's roof drawings to highlight the location of location and quantity of specific roofing materials and/or vegetated roofing systems, as applicable.  In addition, please provide the following based on the appropriate compliance path:

Option 1 - Roofing Materials with SRI equal to or greater than required

• Provide total area (sf) of installed low-sloped roofing materials having a minimum SRI of 78.
• Provide total area (sf) of installed steep-sloped roofing materials having a minimum SRI of 29.
• Indicate the SRI Value for each installed roofing material by completing the fields in the Roofing Materials Table in the Template.

Option 2 - Vegetated Roof

• Total area (sf) of installed vegetated roofing system.

Option 3 - Combo of Roofing Materials with SRI and Vegetated Roof

• Total area (sf) of installed vegetated roofing system.
• Provide total area (sf) of installed low-sloped roofing materials having a minimum SRI of 78.
• Provide total area (sf) of installed steep-sloped roofing materials having a minimum SRI of 29.
• Indicate the SRI Value for each installed roofing material by completing the fields in the Roofing Materials Table in the Template.
• AND (For Projects With Special Circumstances - Any Compliance Path) - Provide an optional narrative to describe any additional comments or notes regarding special circumstances or considerations regarding the project's credit approach.