Why White Roofs Are Green

In the roofing industry, the key word today is “reflectivity.” When the roof reflects the rays of the sun, the result is energy savings and sustainability.

White is the most reflective color. There are a number of white materials that can be used on the surface of the roof to protect the roof membrane, lengthen the life cycle of the roof and provide the most reflection. Reflecting the UV rays of the sun not only protects a roof from excessive temperatures but from damage caused by the ultraviolet radiation. It also helps shed water, reduces interior temperatures and reduces cooling costs. A white roof helps reduce summer temperature spikes. White roofs are used under both solar systems and under rooftop gardening systems for high performance in eliminating leaks.

The U.S. Green Building Council gives buildings seeking a LEED certificate (Leader in Energy & Environmental Design) credits for reducing the urban heat island when using a White roof. LEED is a voluntary national standard for developing high performance, sustainable buildings. It’s a rating system that promotes energy and material efficiency and sustainability in construction.

To be considered “sustainable” a roofing system must include the five “E’s” of high-performance:

• Economics – save money over the life of the product
• Endurance (Long-lasting & Recyclable)
• Energy Savings – lowers the building’s energy consumption
• Engineering
• Environmental Materials

White is Green because

It saves Money (the green stuff)
It Saves Energy – (reduces energy bills)
It’s Environmentally Friendly (Green) because it’s recyclable, provides long-term performance and preserves building components.

For an interesting discussion of how White roofs on buildings can lower the Global temperature http://www.treehugger.com/files/2005/12/white_roofs_to.php