Not long ago Bill and Becka Doering, of Santa Barbara, California, decided they needed a bigger house to accommodate their two young children. After a fruitless search of Santa Barbara's pricey real estate market, the Doerings took Becka's father up on an offer to trade his 102-square-meter (1,100-square-foot) tract house for their 84-square-meter place across town. That helped, but the tract house had just two bedrooms and one bath, so the Doerings remodeled, resulting in a 150-square-meter four-bedroom, two-bath house.
But this wasn't simply about elbow room. The Doerings also wanted their new home to be energy efficient and healthy. So they seized the opportunity to transform the building by hiring a like-minded architect and contractor to help them implement many green building principles. The remodel made improvements in site sustainability, energy and water efficiency, materials and resources, indoor air quality, and more. (See sidebar, page 17.)
Ironically, despite certain high-tech materials and the sophisticated design principles involved, the Doerings' remodel was in some ways a nod to the past. Humans used to build more sustainably and in context with place. The mud city of Djenne, Mali; the sod houses of the American prairie; African rondavals (round huts with grass roofs); the stilted, openwalled thatch shelters of Asia; igloos in the far north--all are examples of how people use natural, local materials and sited their buildings for optimum natural ventilation and climate control. Bill Doering said that following such ancient wisdom and embracing simplicity were key in his family's remodel: "Sometimes we overthink and try to overbuild when some of the most simple principles are what should be guiding us in green building." For example, Doering initially designed a single heating system for hot water and space heating, but it turned out to be prohibitively expensive. "And then we realized that this didn't really make sense," he said. "Why would we spend $30, 000 on a heating system, when our whole intent was to turn it on as little as possible?" In the end, they put a solar water heater on the roof and bought an inexpensive, energy-efficient furnace..
Green building is booming, especially in Europe and along the U.S. coasts. What started as a fringe movement in the 1990s is rapidly moving into the mainstream. In 2005, approximately 2 percent of new homes built in the United States were built "green," meaning in adherence to strong energy efficiency standards and practices, according to the 2006 Green Building SmartMarket Report by McGraw-Hill Construction (MHC). (The commercial sector reached 2 percent in 2004.) MHC projects both the residential and commercial sectors to increase to 10 percent of their markets by 2010. But these figures don't reflect the many undocumented piecemeal improvements made by a wide variety of building owners. In fact, 90 percent of home builders and 85 percent of commercial architects, engineers, and contractors reported some participation in green building activities, according to the MHC report.
This momentum is striking, and is driven partly by widening awareness of the environmental impact of the built environment and the health implications of chemically saturated indoor spaces. In the United States, 40 percent of all energy used goes to heat, light, and cool residential, commercial, and industrial buildings. An additional 8 percent is caught up in the embodied energy of construction and product manufacturing, according to Ed Mazria, an architect who founded the nonprofit group Architecture 2030 to encourage industry and government to reduce building-related emissions. Close to 50 percent of U. S. [CO.sub.2] emissions come from buildings (43 percent for operations and 6 to 8 percent for materials and construction), says Mazria. The energy footprints of buildings in developed countries worldwide are likely comparable, he believes.
Climate-change concerns appear to be an important motivator to build green for both building owners and professionals; because the building sector consumes so much energy, reducing its usage could have a significant impact. In particular, Mazria focuses on reducing or eliminating coal usage, since coal is arguably the dirtiest fossil fuel. He says that a dramatic reduction in building energy consumption would reduce demand so much that the United States could actually shut down coal plants. Based on data from a recent McKin-sey Global Institute report (The Case for Investing in Energy Productivity), Mazria concludes that, "in conservative terms, US$21.6 billion invested in efficiency would result in a 1 quadrillion BTU reduction [in energy consumption]." In the United States, "you would be able to close down 22.3 coal plants for every $21.6 billion invested. You would also reduce natural gas by 204 billion cubic feet a year and cut down on oil by 10.7 billion barrels a year. You'd cut C[O.sub.2] emissions by 86.7 million metric tons, you'd save consumers $8.46 billion a year, and you'd create about 216,000 jobs."
Green building is also getting a boost from efforts around the world to set standards for buildings and educate the public, industry, and policymakers. These programs aim to reduce greenhouse gas emissions and water usage and to improve practices regarding hazardous substances, pollution, and safety. Some third-party ratings systems include LEED (Leadership in Energy and Environmental Design), developed by the U. S. Green Building Council (USGBC); BREEAM (Building Research Establishment's Environmental Assessment Method) in the United Kingdom; Japan's CASBEE (Comprehensive Assessment System for Building Environmental Efficiency); LEED Canada; and Green Star in Australia. There is also a World Green Building Council (WGBC), headquartered in Toronto, Ontario, that is comparing the national ratings systems to compile best practices. The WGBC's 12 member countries represent about 50 percent of the global construction industry.
Smaller organizations in various countries are also contributing. For example, Mazria's Architecture 2030 has issued the 2030 Challenge to encourage governments and industry to reduce the fossil fuel energy consumption of all types of buildings by 50 percent from 2003 levels by 2030 for similar building types in their areas. The challenge sets increasingly tighter standards so that by 2030 all new buildings will be "carbon neutral" (see discussion...