Despite ongoing struggles in the commercial construction market, the green building industry is booming. This is great news considering buildings are responsible for nearly 40 percent of U.S. energy consumption, according to the
International Energy Agency, which is more than any other sector, including transportation. In addition, buildings are major contributors of greenhouse gas emissions.
The implication is clear: Lowering building energy consumption levels is crucial to improving the nation’s overall environmental performance.
Technology and sustainable materials providers are improving at such a great rate that the pioneers of the green building movement now want to do more than just build sustainably—they want to build net-zero. Net-zero buildings boast zero net energy consumption and zero carbon emissions on an annual basis. Where the aim once was to reduce a building’s energy use by adopting low-impact materials and building techniques, the net-zero approach seeks to develop buildings that generate at least as much energy as they consume.
The net-zero approach takes advantage of natural elements such as sunlight, prevailing breezes, topography and other environmental factors to consume less fossil fuel energy. Net-zero buildings are equipped with a range of self-supporting technologies such as wind turbines, solar panels, energy management systems and other power-producing technologies that utilize an area’s specific environmental conditions for power.
Not long ago, net-zero buildings were a green pipedream. Today, they are becoming a reality. Recent advances in computer technology, for example, enable designers to perform complex and precise environmental analyses, and to more accurately test the environmental impact of potential designs. In fact, new programs offer almost real-time feedback on how well a particular design will perform from an environmental perspective.
From this wealth of data, commercial architects can ensure their designs are optimized for the environment in which they’re built. Each design can be tailored to create the most efficient flow of air and light, and to promote the retention and distribution of energy.
Many of the new and emerging technologies also allow the energy performance of buildings to be monitored and studied long after construction is completed, making them useful for building maintenance as well as design.
Yet, the reality is 99 percent of buildings are existing structures, not new ones. This means renovation and upgrades will be critical to producing widespread net-zero buildings. In 2009, the owners of New York City’s iconic Empire State Building launched a $500 million renovation, with a goal of reducing energy use by more than one-third by 2013. Renovation strategies included window replacements, insulation, electrical upgrades and tenant education to reduce the building’s more than 105,000 metric tons of annual carbon dioxide emissions. Project planners predict the Empire State Building eventually will rank in the top 10 percent of ENERGY STAR office buildings.
Also in 2009, President Obama established a goal for all federal agency buildings to be designed to meet net-zero standards by 2030. The General Services Administration (GSA) has particularly ambitious plans for the renovation of the 92-year-old Wayne Aspinall Federal Building and Courthouse in Grand Junction, Colo. Once renovated, the building will include an energy-saving geothermal heating and cooling system that uses the ground to control temperatures, and a solar panel array that is projected to generate enough energy to balance out the building’s electrical requirements. If successful, the courthouse will become the first net-zero building on the National Register of Historic Places.
Net-zero building is still in its infancy, but offers a viable next step in sustainable building practices.