Green building is the practice of increasing the efficiency with which buildings use resources — energy, water, and materials — while reducing building impacts on human health and the environment during the building's lifecycle, through better siting, design, construction, operation, maintenance, and removal.

^{Green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment by:}

• Efficiently using energy, water, and other resources
• Protecting occupant health and improving employee productivity
• Reducing waste, pollution and environmental degradation

A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally.  Other commonly used terms include sustainable design and green architecture.

The related concepts of sustainable development and sustainability are integral to green building. Effective green building can lead to 1) reduced operating costs by increasing productivity and using less energy and water, 2) improved public and occupant health due to improved indoor air quality, and 3) reduced environmental impacts by, for example, lessening storm water runoff and the heat island effect. Practitioners of green building often seek to achieve not only ecological but aesthetic harmony between a structure and its surrounding natural and built environment, although the appearance and style of sustainable buildings is not necessarily distinguishable from their less sustainable counterparts.

Green Building Practices

Green building brings together a vast array of practices and techniques to reduce and ultimately eliminate the impacts of buildings on the environment and human health. It often emphasizes taking advantage of renewable resources, e.g., using sunlight through passive solar, active solar, and photovoltaic techniques and using plants and trees through green roofs, rain gardens, and for reduction of rainwater run-off. Many other techniques, such as using packed gravel for parking lots instead of concrete or asphalt to enhance replenishment of ground water, are used as well. Effective green buildings are more than just a random collection of environmental friendly technologies, however. They require careful, systemic attention to the full life cycle impacts of the resources embodied in the building and to the resource consumption and pollution emissions over the building's complete life cycle.

On the aesthetic side of green architecture or sustainable design is the philosophy of designing a building that is in harmony with the natural features and resources surrounding the site. There are several key steps in designing sustainable buildings: specify 'green' building materials from local sources, reduce loads, optimize systems, and generate on-site renewable energy.

Green Building Materials

Building materials typically considered to be 'green' include rapidly renewable plant materials like bamboo and straw, lumber from forests certified to be sustainably managed, dimension stone, recycled stone, recycled metal, and other products that are non-toxic, reusable, renewable, and/or recyclable (eg Trass, Linoleum, sheep wool, panels made from paper flakes, baked earth, rammed earth, clay, vermiculite, flax linen, sisal, seagrass, cork, expanded clay grains, coconut, wood fibre plates, calcium sand stone...). Building materials should be extracted and manufactured locally to the building site to minimize the energy embedded in their transportation.

Reduced Energy Use
Main articles: Low-energy house and Zero-energy building

Green buildings often include measures to reduce energy use. To increase the efficiency of the building envelope, (the barrier between conditioned and unconditioned space), they may use high-efficiency windows and insulation in walls, ceilings, and floors. Another strategy, passive solar building design, is often implemented in low-energy homes. Designers orient windows and walls and place awnings, porches, and trees to shade windows and roofs during the summer while maximizing solar gain in the winter. In addition, effective window placement (daylighting) can provide more natural light and lessen the need for electric lighting during the day. Solar water heating further reduces energy loads.

After heating and cooling loads are reduced, high efficiency cooling, heating, and water heating equipment, along with insulated hot water pipes and properly sealed and insulated ducts increase whole house efficiency. Higher efficiency appliances and other electric devices not only lowers direct energy use, but also lowers cooling loads in the summer by producing less waste heat. Similarly, fluorescent lighting, which uses two-thirds to three-fourths less energy than conventional incandescent bulbs, lowers direct electricity use and cooling loads. Other improvements include adding thermal mass to stabilize daily temperature variations, absorption chillers, optimizing houses for natural ventilation, cool roofs in warm climates, heat recovery ventilation and hot water heat recycling.

Finally, onsite generation of renewable energy through solar power, wind power, hydro power, or biomass can significantly reduce the environmental impact of the building. Power generation is generally the most expensive feature to add to a building.

Reduced Waste

Green architecture also seeks to reduce waste of energy, water and materials. During the construction phase, one goal should be to reduce the amount of material going to landfills. Well-designed buildings also help reduce the amount of waste generated by the occupants as well, by providing on-site solutions such as compost bins to reduce matter going to landfills.

To reduce the impact on wells or water treatment plants, several options exist. "Greywater", wastewater from sources such as dishwashing or washing machines, can be used for subsurface irrigation, or if treated, for non-potable purposes, e.g., to flush toilets and wash cars. Rainwater collectors are used for similar purposes.

Centralized wastewater treatment systems can be costly and use a lot of energy. An alternative to this process is converting waste and wastewater into fertilizer, which avoids these costs and shows other benefits. By collecting human waste at the source and running it to a semi-centralized biogas plant with other biological waste, liquid fertilizer can be produced. This concept was demonstrated by a settlement in Lubeck Germany in the late 1990s. Practices like these provide soil with organic nutrients and create carbon sinks that remove carbon dioxide from the atmosphere, offsetting greenhouse gas emission. Producing artificial fertilizer is also more costly in energy than this process.

Low vs. High-Density Residential Areas

An aspect of concern in consideration of green building design is the phenomenon of urban sprawl. Urban sprawl is the outward movement away from the cities in the surrounding hinterlands creating suburbs. Movement into the suburbs creates low density housing, which brings along many environmental impacts due to increased transportation, larger houses using more building materials, and larger amounts of land use.

United States

The United States has established several sustainable design organizations and programs.

The National Association of Home Builders, a trade association representing home builders, remodelers and suppliers to the industry, has created a voluntary residential green building program known as NAHBGreen (www.nahbgreen.org). The program includes an online scoring tool, national certification, industry education, and training for local verifiers. The online scoring tool is free to builders and to homeowners.

The Green Building Initiative is a non-profit network of building industry leaders working to mainstream building approaches that are environmentally progressive, but also practical and affordable for builders to implement. The GBI has developed a web-based rating tool called Green Globes, which is being upgraded in accordance with ANSI procedures.

The United States Environmental Protection Agency's Energy Star program rates commercial buildings for energy efficiency and provides Energy Star qualifications for new homes that meet its standards for energy efficient building design.

In 2005, Washington State became the first state in the United States to enact green building legislation.  According to the law, all major public agency facilities with a floor area exceeding 5,000 square feet (465 m²), including state funded school buildings, are required to meet or exceed LEED standards in construction or renovation. The projected benefits from this law are 20% annual savings in energy and water costs, 38% reduction in waste water production and 22% reduction in construction waste.

Charlottesville, Virginia became one of the first small towns in the United States to enact green building legislation.  This presents a significant shift in construction and architecture as LEED regulations have formerly been focused on commercial construction. If US homeowner interest grows in "green" residential construction, the companies involved in the production and manufacturing of LEED building materials will become likely candidates for tomorrow's round of private equity and IPO investing.

                  BHES is a newly established company with professionals experienced in green remodels, energy, and engineering. 

This Section Is Temporarily Under Construction!  Check Back Soon!
Click Here!