When it was time to replace the brown clay tile roof of the Palolo Chinese Home in Honolulu, HI, Lester Obayashi of Obayashi Design Group wanted a product that was lightweight, looked good and contributed to the points needed for LEED certification. One credit solely addresses the type of roofing chosen: Sustainable Sites Credit – Heat Island Reduction, Roofing (credit numbers vary across LEED Rating Systems). In order to qualify for this credit, the product selected has to have a Solar Reflectance Index (SRI) greater than or equal to 29 for a roof slope greater than 2:12; SRI is calculated using reflectivity and emissivity values.
Obayashi chose DECRA Tile in Mist Grey to meet LEED requirements. DECRA products are made of stone coated steel, and were tested using ASTM E 908 and ASTM E 408 - acceptable standards for reflectance and emittance. In addition to contributing points to LEED certification, the product is lightweight, visually appealing, and in keeping with the original style of the roof.
Additionally, products made of steel will contribute to points under Materials & Resources – Recycled Content. According to the Steel Recycling Institute, steel is the most recycled product in the world. On average, a steel product will contain 25 to 30 percent recycled content.
A particular challenge was getting neighborhood approval for the lighter color - the original roof was a brown clay tile. However, in the end, the neighborhood allowed the Mist Grey color in light of the LEED certification goal.
In 2007 the Paolo Chinese Home was awarded certification under LEED-CI.
Mist Grey DECRA product comes in two profiles, Shake and Tile. When considered for use on a LEED certified project, the use of Mist Grey can contribute to the points available in the Sustainable Sites Credit (points awarded vary across the different rating systems).