Recycled rainwater, solar chimneys, rooftop gardens, geothermal cooling systems, solar panels, natural ventilation: These are just some of the tricks in an arsenal of design techniques builders are using to create structures that tread lightly on the earth.
The American Institute of Architects has highlighted 10 buildings it considers the best of the breed. The group is trying to demonstrate the possibility of creating sustainable, environmentally friendly architecture that dramatically reduces energy use and thus minimizes "carbon footprint" — the amount of carbon dioxide gas, which contributes to global warming, that the buildings generate.
The buildings include a federal courthouse, a middle school, science labs and a Connecticut water purification facility. But they share a common theme, says the American Institute of Architects’ Henry Siegel.
"They use smart design, rather than expensive technology, to achieve their green goals. This is really becoming mainstream," says Siegel, vice chair of the organization's environmental committee. "All architecture firms are interested in this. People are seeing this is not a technology issue but a design issue, and to do a lot of these things correctly at the design process doesn’t cost anything."
Why bother? Because, good design can save both the environment and money. The U.S. Department of Energy says that conventional buildings in the U.S eat up 71 percent of the country’s electricity output and are responsible for 38 percent of the U.S.' carbon dioxide emissions, equal to the combined total emissions of Japan, France and the U.K.
And as these buildings demonstrate, it’s often not brand new technology that's needed, but rather an attention to details of the design that can make the biggest difference. For instance, orienting the building’s windows and open spaces to make better use of natural daylight lessens the need for electric lights. Some buildings use natural ventilation, including "cooling towers" to capture and redirect natural breezes into the space. Many make use of "solar chimneys," an ancient building technique that creates sun-heated shafts of air which rise up and out of the building, sucking cooler air in from below and creating a natural ventilation.
Smart use of roof overhangs provide sun shade for windows that helps lessen heat inside the building and reduces the need for electricity-guzzling air conditioning, while still allowing in natural light. Green gardens on the rooftops provide insulation, further reducing the need for temperature controls inside. Many of the building capture rainwater or deep sea water for use in thermal cooling systems.
The savings can be substantial. A study prepared for the Massachusetts Technology council found that buildings credited with "LEED" status (Leadership in Energy and Environmental Design) — a designation given by the U.S. Green Building Council based on how well a green building reduces its energy use and environmental impact — use on average 25 percent to 30 percent less energy than conventional buildings and cost, on average, only 2 percent more to build.
Most of the buildings on this list reduce energy consumption by far more, in some cases 80 percent. And they do this, Siegel notes, without sacrificing an aesthetic appeal; they are, in short, pretty cool looking buildings.
© 2012 Forbes.com