With snow falling this time of year, white roofs are a
common sight in many parts of the nation. But if U.S. Department of Energy
(DOE) Secretary Steven Chu had his way, Florida roofs would be white, too
you’re thinking of putting on a new roof, make it white,” Chu told host Jon
Stewart during an interview earlier this year on The Daily Show. “It costs
no more to make it white than to make it black. If you’re in a warm climate,
a white roof can lower air conditioning [costs] anywhere from 5 percent to
15 or 20 percent. Plus, lower air-conditioning bills mean less electricity
generated, which means less carbon dioxide emitted.”
The concept of using white or reflective roofing to lower
home-cooling costs has deep roots. Residents living in warm Mediterranean
spots like the Greek island of Santorini are known for whitewashing not only
roofs but entire buildings and cities to reflect heat. But in countries with
air conditioning widely available, the benefits of white buildings were
Today, retailers and large
businesses are leading the charge in the white roof revolution. More than 75
percent of the nation’s 4,268 Walmart stores boast white, energy- efficient
The National Rural Electric Cooperative Association, an
Arlington, Va.-based national service organization representing more than
900 consumer-owned, not-for-profit electric cooperatives, uses a white roof
and unique cooling techniques to lower energy bills in an 11-story companion
building at its headquarters complex.
How much of a difference can a roof’s color make? DOE’s
Lawrence Berkeley National Laboratory has studied “cool roof” techniques and
results since the 1980s. According to the lab, replacing conventional roofs
with a cool variety — using solar-reflective materials or just white paint —
can reduce air-conditioning energy use, on average, 20 percent.
Cool roofs aren’t perfect for everyone. According to
ENERGY STAR, buildings with high air-conditioning bills, large roof
surfaces, and lower levels of insulation located in hot, sunny climates
benefit the most from cool roofing. It’s also more cost-effective to wait to
install ENERGY STAR- qualified roofing products until you’re re-roofing or
applying a new coat of paint as part of regular maintenance.
Other options are available to increase your roof’s energy
efficiency as well. Solar-reflective roofing comes in a wide variety of
colors and materials like asphalt shingles, clay and cement tiles, and
metal. Just look for the ENERGY STAR label and certification from the Cool
Roof Rating Council.
To help with cost, all ENERGY STAR-certified metal and
reflective asphalt shingles qualify for an energy-efficiency tax credit
through the American Recovery and Reinvestment Act of 2009. Roofing
efficiency upgrades made to existing homes through 2010 are eligible for a
tax credit of 30 percent of the cost of materials, up to $1,500.
Installation costs are not covered.
To learn about efficient roofing options and available tax
credits, visit www.energystar.gov, keyword, “reflective roofing.”