Recognizing that the 4.5 million existing buildings in the United States can achieve a 20% to 30% reduction in energy use, the U.S. Environmental Protection Agency (EPA), the U.S. Department of Energy (DOE) and the U.S. Green Building Council (USGBC) recently announced a partnership between ENERGY STAR and Leadership in Energy and Environmental Design, (LEED) to help ease the nation’s energy crunch.

The USGBC is introducing LEED for existing buildings. LEED is the USGBC’s sustainable building rating system for certifying green design and construction in new buildings, which has already been adopted by a large number of private and public concerns for new construction projects. During the past year, the USGBC has been developing green building standards for existing-building upgrades and operations.

According to the Leonardo Academy (Madison, WI) which used data from the DOE Energy Information Agency, annual electrical demand in all existing buildings could be potentially reduced by nearly 45 gW and save some $21 billion a year in energy costs if all commercial buildings were made more efficient. That amounts to eliminating the need to build eighty-five 500-MW power plants. It also translates into reducing CO2 emissions by more than 275 million tons annually. That does not include efficiencies that can be realized in homes and other residential buildings.

LEED for existing buildings incorporates many specifications set by the ENERGY STAR program sponsored by the EPA and the DOE. ENERGY STAR recognizes buildings that are in the top 25% of the market for energy performance. “When it comes to measuring performance of energy use in buildings, ENERGY STAR sets the bar,” said Steven Winter, chairman of the USGBC’s board of directors and president of Steven Winter Associates, Inc. “LEED draws upon national and regional standards for site development, water use, energy use, materials and indoor environmental quality.

Based on EPA and DOE success in helping buildings improve their energy performance, it only made sense to build the widely used Energy Star specifications into our rating system. Not only do building owners and occupants benefit from reduced energy bills, but they get all the advantages of a superior office environment and public recognition for their leadership.”

“About 71% of non-residential, existing buildings are 20 years or older,” said Jean Lupinacci, director of commercial and industrial branch of ENERGY STAR. “We know there is a wealth of energy savings and thereby reduced emissions that can be realized from existing buildings. Partners in the EPA’s ENERGY STAR program average 30% to 40% return on investment to retrofit older buildings with high-efficiency lighting, for example. LEED for existing buildings is an important tool for helping to upgrade and operate buildings at their highest levels of environmental performance. At the EPA, we’re pleased to participate in the development of this version of the USGBC’s rating system because both LEED and ENERGY STAR are voluntary programs that are transforming the building industry.”