Glossary: Energy Efficiency /
Green Buildings
Definitions of terms relating to energy-efficient technologies
and elements of green buildings.
Certified forest product: A forest product that is certified as sustainable/suitable for use in a green building is from a managed forest that has passed rigorous guidelines for responsible harvesting (rather than over-harvesting), ecosystem management and conservation, and long-term sustainable resource management. The Scientific Certification Systems’ Forest Conservation Program employs the principles of the Forest Stewardship Council to ensure that certified forests meet standards for sound forest management.
Chain-of-custody certification: A product certified through chain-of-custody has met certification requirements from production through distribution and sales. For a forest product, this means the wood has been extracted from the forest according to guidelines for sustainability, and that the process through which it is distributed to consumers is monitored to ensure that a product is certified as claimed. Learn more about chain-of-custody certification from Scientific Certification Systems.
Clean energy: Clean energy can be generally defined as energy from renewable sources such as biomass, wind, or solar power. The goal of clean energy is to have a low environmental impact, with low or zero emissions, and a minimal impact on the physical surroundings. Hydropower can be defined as clean energy due to zero emissions, but today's hydropower still often has substantial impacts on aquatic ecosystems. Waste-burning and wood-burning plants that capture emissions can be clean energy generators. Fossil fuels do not provide clean energy because of their emissions and environmental impacts. Learn more about clean energy technologies.
Compact fluorescent lamp (lightbulb): Compact fluorescent lamps (CFLs) use an advanced technology that uses much less energy than incandescent or standard fluorescent light bulbs. They come in a range of styles and sizes, and electric utilities often provide instant or mail-in rebates for CFL purchases.
Daylighting (natural lighting): Daylighting is the use of various design techniques to enhance the use of natural light in a building. Daylighting decreases reliance on electric lights and mechanical systems through the use of windows, skylights, light shelves, and other techniques that maximize sunlight while minimizing glare and excess heat.
Energy efficiency: Energy efficiency refers to products or systems designed to use less energy for the same or higher performance than regular products or systems. Energy-efficient buildings are designed to use less energy than traditional buildings; see green buildings for details. Saving energy through efficiency also saves money on utility bills and protects the environment by reducing fossil fuel consumption and emissions. Combining energy efficiency with renewable energy is even better for the environment.
Green building: A green building is a building that has been constructed or renovated to incorporate design techniques, technologies, and materials that minimize its overall environmental impacts. Among these reduced impacts are reduced fossil fuel use for electricity and heat, minimal site disruption, lower water consumption, and fewer pollutants used and released during construction and occupation. The term “high-performance building” is often used when referring specifically to the energy efficiency and productivity benefits of a building, whereas “green building” refers to the broader environmental considerations of a building, including high-performance aspects. Learn more about green buildings.
High-performance building: A high-performance building may be very similar to a green building but specifically aims to be energy efficient and provide productivity and health benefits to its occupants. Learn more about high-performance buildings from the Department of Energy.
High-performance windows and doors: These windows and doors are made of materials that seal out air leaks and reduce heat loss and gain, increasing the efficiency of a building.
Indoor air quality: Indoor air quality can have significant impacts on human health. Poor indoor air quality results from chemical, physical, or biological contaminants in indoor air, such as toxic paint gases, chemicals in carpeting and treated wood, mold, and dust mites. High levels of these contaminants in the air can cause moderate to severe health problems. Green buildings seek to improve indoor air quality by using building materials with low toxicity and proper ventilation systems.
Indoor environmental quality: Indoor environmental quality takes into consideration all impacts of the indoor environment on human health and performance, including indoor air quality, daylighting and views, and visual and thermal comfort. Green buildings seek to optimize indoor environmental quality through design that includes properly designed heating, ventilation, and air conditioning systems, abundant windows and proper use of daylighting, and well-sealed doors and windows.
Passive solar design: Passive solar design is the use of various design techniques in a building to capitalize on heat and light from the sun and reduce the need for mechanical and electric systems. These techniques include daylighting, large south-facing windows, natural shading and ventilation, and building materials that absorb heat from the sun and slowly release it to warm the building. Proper use of passive solar design can reduce heating bills as much as 50%.
Renewable energy: Renewable energy comes from sources that can be replenished on a human time scale, such as biomass (wood), or that are essentially inexhaustible, such as waste and geothermal, wind, and solar energy. Fossil fuels are non-renewable energy sources; there is a finite supply of them. Renewable energy is also often clean energy; it can be generated with few or zero emissions and little to no environmental damage.
Site preservation: Site preservation is the minimal disruption of a building on its surrounding environment. Building reuse and use of existing building sites as opposed to previously unused land are the most impactful forms of site preservation. Buildings should not be located on sites that are environmentally fragile and should not interfere with the land’s natural hydrologic functions. Reducing stormwater runoff and using original trees and vegetation are additional ways to maintain the natural landscape.
Solar photovoltaics (PV): PV converts sunlight directly into electricity. PV is made from semiconductor materials, and does not create any pollution, noise, or other impacts on the environment. Homes and businesses may incorporate solar panels and arrays as a source of clean energy. Learn more about solar photovoltaics.
Tight construction: Tight construction is the elimination of gaps and holes in a building’s exterior (envelope) through air-sealing and proper ventilation. This practice can eliminate unwanted drafts and pollutants and reduce energy bills.
Urban heat islands: Dark-colored surfaces such as roofs and pavement absorb heat from the sun more than light-colored surfaces. In urban areas, a combination of many dark surfaces plus a lack of shade plants, intensifies this effect and creates “urban heat islands.” These urban areas stay warmer than the surrounding suburbs and increase the need for electric cooling systems. One solution is the use of lighter-colored materials in building construction. The use of well-placed vegetation to increase shade or green roof systems can also minimize urban heat island effects and increase building energy efficiency.
Water efficiency: Water efficiency refers to practices, products, or systems that use less water than traditional products or systems without sacrificing performance. Water-efficient products can include graywater use and low-flow water fixtures (such as toilets or faucets). Water-efficient practices can include landscaping with plants that require less water, use of rainwater for irrigation, and stormwater management.
Whole-building design: Whole-building design is the integration of a building’s elements and systems to maximize its energy, environmental, and financial performance. A critical element of this approach is the integration of energy systems to maximize efficiency and reduce the need for electricity, heating, and cooling technologies. The whole-building approach also considers construction materials, indoor environmental quality, acoustics, and other building factors like design and siting to minimize a building’s impacts on its surroundings and improve its performance for occupants.