NYC Building Code: Roof Reflectance Requirements

1504.8 Reflectance. Roof coverings on roofs or setbacks with slope equal to or less than three two units vertical in 12 units horizontal (25 17 percent) shall be white in color or EnergyStar rated as highly reflective for at least 75 percent of the area of the roof or setback surface. have:

1. A minimum initial solar reflectance of 0.7 in accordance with ASTM C 1549 or ASTM E 1918, and a minimum thermal emittance of 0.75 as determined in accordance with ASTM C 1371 or ASTM E 408; or

2. A minimum SRI of 78 as determined in accordance with ASTM E 1980.

Exceptions:

1. Terraces on setbacks comprising less than 25 percent of the area of the largest floor plate in the building.

2. Green roofs Any portion of a roof covered by a green roof system, including such a system with agricultural plantings, in compliance with Section 1507.16 shall be permitted to comprise part or all of the 75 percent required area coverage.

3. Roofs Any portion of a roof used as outdoor recreation space by the occupants of the building shall be permitted to be either that is landscaped, covered by wood decking or covered with a walking surface or other protective surface, provided that such walking surface or protective surface has with an albedo of 30 percent or greater a minimum initial solar reflectance of 0.3 as determined in accordance with ASTM C 1549 or ASTM E 1918.

4. Ballasted roofs, provided that the ballast has a minimum initial solar reflectance of 0.2 as determined in accordance with ASTM C 1549 or ASTM E 1918.

5. Any portion of a roof that is under mechanical equipment, flush mounted solar panels lying directly on the roof surface, duckboarding, decking, platform, roof tank, cooling tower or any other rooftop structure or equipment exempted by rule by the commissioner.

6. Any roof or portion of a roof composed of glass, metal, clay or concrete tile or plastic/rubber intended to simulate clay or concrete tile, wood, or slate.

7. Any portion of a roof used by a school or daycare center as a playground for children.

8. Any roof, if the amount of rooftop space not subject to exceptions 1 through 7 is in the aggregate less than 100 square feet (9.3 m²).