Green Building

Green buildings are structures that are designed to have a reduced environmental impact compared with standard construction methods and materials. When the concept was introduced in the 1970s because of concerns over rising energy use and environmental pollution, green building was largely carried out by people constructing their own homes. Since 2000, however, the growing concern over global warming, water resources, and sustainability has led to a movement that is influencing development in the public and private sectors across the world, from houses to skyscrapers. The standards that have been developed to certify green buildings are part of the general 21st-century shift away from government regulation and toward voluntary, performance-based standards. Because of the focus on economic and environmental but not social issues, green buildings do not generally fit the traditional definition of sustainability; instead, they are sometimes called high-performance buildings.

According to the nonprofit U.S. Green Building Council (USGBC), buildings within the United States produce nearly 40% of global carbon dioxide emissions and 30% of waste output, while consuming 7% of the world's electricity, 40% of its raw materials, and 14% of the potable water. In most cases, there is relatively little that building inhabitants can do to reduce these figures once the structure is in place. The responsibility for producing more environmentally friendly buildings is therefore placed on the shoulders of those who design and construct them. At the same time, there is tremendous potential for reducing resource consumption and waste production by better building designs and construction practices.

There are three general approaches to greening buildings. The first is to rely on existing vernacular building practices and materials, such as adobe structures in desert climates to take advantage of large temperature fluctuations or raised floors in hot and humid climates to allow for airflow. The second approach is high-tech, relying on new materials and processes to reduce resource use and minimize waste. The third is biomimicry, imitating natural processes and using natural materials. Each has different implications in terms of capital requirements, marketability, and effectiveness. The technological approach dominates the industry at the present time, as seen by the term high-performance buildings.

There is no single definition of what makes a building green. The Leadership in Energy and Environmental Design (LEED) standards of the USGBC considers six dimensions: (1) sustainable sites, (2) water efficiency, (3) energy and atmosphere, (4) materials and resources, (5) indoor environmental quality, and (6) design innovation. The idea is to go beyond simply using less water or energy, by considering how multiple components of a building's design work together in a mini-ecosystem that consists of the site and its relationship to the surrounding networks of transportation, wildlife habitat, and urban space; the indoor environment, including emissions from paint and carpet; and the sources and sinks for the materials that go into the building and the wastes that come out. The complexity of a green building means that architects, engineers, and construction managers have to work closely together to achieve the goals of the project.

Modern building using energy-efficient measures, including solar panels and reflective glass

Source: David Hills/iStockphoto.

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