Sustainable building ........Energy Efficiency

Approximately 50 percent of the energy use in buildings is devoted to producing an artificial
indoor climate through heating, cooling, ventilation, and lighting.4 A typical building’s
energy bill constitutes approximately 25 percent of the building’s total operating
costs. Estimates indicate that climate-sensitive design using available technologies could
cut heating and cooling energy consumption by 60 percent and lighting energy requirements
by at least 50 percent in U.S. buildings.5

Returns on investment for energy-efficiency measures can be
higher than rates of return on conventional and even high yielding
investments. Participants in the Green Lights program
of the U.S. Environmental Protection Agency (EPA)
have enjoyed annual rates of return of over 30 percent for
lighting retrofits. When participants complete all program related
improvements, Green Lights could save over 65 million
kilowatts of electricity, reducing the nation’s electric bill
by $16 billion annually.6
If the United States continues to retrofit its existing building
stock into energy-efficient structures and upgrade building
codes to require high energy efficiency in new buildings, it
will be able to greatly reduce the demand for energy resources.
This reduction, in turn, will lessen air pollution, contributions
to global warming, and dependency on fossil fuels.