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GREEN BUILDING GLOSSARYOzarks Green Building Coalition has compiled this glossary of Green Building terms.
ARU's: – Air Rotation Units also use outside air to condition a building. However, the units only bring in outside air during occupied times. When the building is not occupied, the ARU rotates the higher warm air with the lower cool air in the space, keeping the building satisfied without taking into account the necessary air quality requirements based on occupancy.
Absorption Chiller: A water chilling process in which cooling is accomplished by the evaporation of a fluid (usually water), which is then absorbed by a different solution (usually lithium bromide), then evaporated under heat and pressure. The fluid is then condensed with the heat of condensation rejected through a cooling tower.
Acceptable indoor air quality: Air in an occupied space toward which a substantial majority of occupants express no dissatisfaction and in which there are not likely to be known contaminants at concentrations leading to exposures that pose a significant health risk (ASHRAE 62-1989 revision)
Active solar heating: Heat from the sun is absorbed by collectors and transferred by pumps or fans to a storage unit for later use or to the house interior directly. Controls regulating the operation are needed.
Active solar water heater: Heat from the sun is absorbed by collectors and transferred by pumps to a storage unit. The heated fluid in the storage unit conveys its heat to the domestic hot water of the house through a heat exchanger. Controls regulating the operation are needed.
Adaptability: Design strategy that allows for multiple future uses in a space as needs evolve and change. Adaptable design is considered a sustainable building strategy as it reduces the need to resort to major renovations or tearing down a structure to meet future needs.
Agricultural by-products: Products developed in agriculture that were not a primary goal of the agricultural activity. The most commonly used as a building product is straw, which is used in wall panels or as bales in a technique called straw bale construction with the bales used as building blocks. The straw bale construction method was common in the plains states at the turn of the century and is currently being revived in Europe and the U.S.
Agricultural Waste: Materials left over from agricultural processes (e.g., wheat stalks, shell hulls, etc.). Some of these materials are finding new applications as building materials and finishes. Examples include structural sheathing and particleboard alternatives made from wheat, rye and other grain stalks, and panels made from sunflower seed hulls.
Air Changes Per Hour (ACH): The movement of a volume of air in a given period of time; if a house has one air change per hour, it means that the air in the house will be replaced in a one-hour period.
Air Change Effectiveness: A measurement of the performance of a ventilation system, by measuring the age of air in a volume. Often accomplished by using a tracer gas decay technique.
Air Cleaning: Indoor-air quality-control strategy to remove various airborne particulates and/or gases from the air. Most common methods are particulate filtration, electrostatic precipitation, and gas sorption.
Air Exchange Rate: The rate at which outside air replaces indoor air in a given space.
Airborne Particulates: Total suspended particulate matter found in the atmosphere as solid particles or liquid droplets. Chemical composition of particulates varies widely, depending on location and time of year. Sources of airborne particulates include dust, emissions from industrial processes, combustion products from the burning of wood and coal, combustion products associated with motor vehicle or non-road engine exhausts, and reactions to gases in the atmosphere.
Air Handling Unit: Equipment that includes a fan or blower, heating and/or cooling coils, regulator controls, condensate drain pans, and air filters.
Air Plenum: Any space used to convey air in a building, furnace, or structure. The space above a suspended ceiling is often used as an air plenum.
Air Pollutant: Any substance in air that could, in high enough concentration, harm man, other animals, vegetation, or material. Pollutants may include almost any natural or artificial composition of airborne matter capable of being airborne. They may be in the form of solid particles, liquid droplets, gases, or in combination thereof. Generally, they fall into two main groups: (1) those emitted directly from identifiable sources, and (2) those produced in the air by interaction between two or more primary pollutants, or by reaction with normal atmospheric constituents, with or without photoactivation. Exclusive of pollen, fog, and dust, which are of natural origin, about 100 contaminants have been identified. Air pollutants are often grouped in categories for ease in classification; some of he categories are: solids, sulfur compounds, volatile organic chemicals, particulate matter, nitrogen compounds, oxygen compounds, halogen compounds, radioactive compound, and odors.
Air Quality Construction Management Plan: A systematic plan for addressing construction practices that can impact air quality during construction and continuing on to occupation.
Alternative Energy: Energy from a source other than the conventional fossil-fuel sources of oil, natural gas and coal (i.e., wind, running water, the sun). Also referred to as "alternative fuel."
Alternative Fuels: Substitutes for traditional liquid, oil-derived motor vehicle fuels like gasoline and diesel. Includes mixtures of alcohol-based fuels with gasoline, methanol, ethanol, compressed natural gas, and others.
Ancient Forest Friendly: A philosophy of not contributing to the destruction of ancient and endangered forests in the production of paper materials, manufactured with a high percentage of post- consumer waste and no virgin fiber from old-growth, ancient or endangered forests:
Annual Consumption: Annual consumption refers to the amount of electricity used by a consumer in one year and is typically measured in kilowatt-hours (kWh). This information is available on your electricity bill or by contacting your energy provider.
Asbestos: A mineral fiber that can pollute air or water and cause cancer or asbestosis when inhaled. EPA has banned or severely restricted its use in manufacturing and construction.
ASHRAE: American Society of Heating, Refrigeration and Air Conditioning Engineers.
Bake-out: Process by which a building is heated in an attempt to accelerate VOC emissions from furniture and materials.
Benefit/Cost Analysis: An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection.
Best Management Practice (BMP): Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from non-point sources.
Bioaccumulants: Substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted.
Biochemical Oxygen Demand (BOD): A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution.
Bioconcentration: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium.
Biodegradable: Capable of decomposing under natural conditions. Waste material composed primarily of constituent parts that occur naturally, are able to be decomposed by bacteria or fungi, and are absorbed into the ecosystem. Wood, for example, is biodegradable, while plastics are not.
Biological Contamination: Contamination of a building environment caused by bacteria, molds and their spores, pollen, viruses, and other biological materials. It is often linked to poorly designed and maintained HVAC systems. People exposed to biologically contaminated environments may display allergic-type responses or physical symptoms such as coughing, muscle aches and respiratory congestion.
Biomass: All of the living material in a given area; often refers to vegetation.
Bioremediation: The cleanup of a contaminated site using biological methods, i.e., bacteria, fungi, plants, etc. Organisms are used to either break down contaminants in soil or water, or accumulate the contaminants in their tissue for disposal. Many bioremediation techniques are substantially less costly than traditional remediation methods using heat, chemical or mechanical means.
Bioswale: A technology that uses plants and soil and/or compost to retain and cleanse runoff from a site, roadway, or other source.
Blackwater: Water that contains animal, human, or food waste.
Blower Door Test: Professional energy auditors use blower door tests to help determine a home's airtightness, which is associated with problems of air leakage, moisture condensation, uncomfortable drafts and the home’s air quality. A blower door is a powerful fan that mounts into the frame of an exterior door and pulls air out of the house, lowering the air pressure inside. Outside air then flows in through all unsealed cracks and openings. Read more about blower door test.
Brownfields: Abandoned, idled, or under-used industrial and commercial facilities where expansion or redevelopment is complicated by real or perceived environmental contamination. The “brownfield” designation is a specific designation made by the Environmental Protection Agency. Many “green” guideline standards provide points for building in “brownfield” areas.
Building Cooling Load: The hourly amount of heat that must be removed from a building to maintain indoor comfort (measured in British thermal units [Btu]).
Building Envelope: The outer shell of a home or building, including the roof, walls, doors, windows and foundation, that separates conditioned (heated or cooled) indoor areas from external environment. Common measures of the effectiveness of building envelopes include protection from the external environment, indoor air quality, durability and energy efficiency. To achieve these objectives, building envelopes must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier.
Building for Environmental and Economic Sustainability (BEES) - Software program developed by the NIST (National Institute of Standards and Technology). It is aimed at designers, builders, and product manufacturers. It provides a way to balance the environmental and economic performance of building products. BEES measures the environmental performance of building products by using an environmental life-cycle assessment approach specified in the latest versions of ISO 14000 draft standards. All stages in the life of a product line are analyzed: raw material acquisition, manufacture, transportation, installation, use, and recycling and waste management. Economic performance is measured using the ASTM standard life cycle cost method, which covers the costs of initial investment, replacement, operation, maintenance and repair, and disposal. Environmental and economic performance are combined into an overall performance measure using the ASTM standard for Multi-Attribute Decision Analysis. The BEES methodology is being refined and expanded under sponsorship of the EPA's Environmentally Preferable Purchasing Program. BEES currently addresses categories of product choices and is not specific to a type of product.
Building Flush-Out: See Flush-Out.
Building Related Illness: Diagnosable illness whose cause and symptoms can be directly attributed to a specific pollutant source within a building (e.g., Legionnaire's disease, hypersensitivity, pneumonitis). (See: sick building syndrome; biological contamination). The term “building related illness” (BRI) is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants.
Buy Locally: In addition to the physical attributes of green products, one should consider the origin of products as well. Buying regional products reduces transportation costs and energy and keeps dollars in the local economy. A major tenet of sustainability is making use of resources from the immediate region. This results in a greater understanding of the region, its characteristics and resources, and the impact of using or producing that resource on that region.
Carbon dioxide: A naturally occurring greenhouse gas in the atmosphere, concentrations of which have increased (from 280 parts per million in pre-industrial times to over 350 parts per million today) as a result of humans burning coal, oil, natural gas and organic matter (e.g., wood and crop wastes). It is attributed with being a major contributor to global warming.
Carbon Dioxide Monitoring: A method for determining indoor air quality by using the concentration of carbon dioxide as an indicator. Although the level of CO2 is a good general indicator of air quality, it is reliant on the presence of certain conditions and must be applied accordingly.
Carbon Dioxide Sensor: Device for monitoring the amount of carbon dioxide in an air volume.
Carbon Footprint: A measure of the your impact on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide.
Carbon Monoxide (CO): A colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion, usually associated with incomplete combustion of gas stoves, fireplaces, kerosene appliances, tobacco smoke, and automobile exhaust. Proper ventilation is important to prevent negative health effects such as fatigue, dizziness, nausea and even death.
Carbon Neutral: Adding no new carbon dioxide emissions to the atmosphere; balancing the amount of carbon dioxide produced from activities like driving a car or producing electricity with an equal amount offset by planting trees (which use CO2), supporting renewable energy from solar and wind.
Carbon Rationing: Limiting the amount of carbon you introduce into the environment each year. Carbon rationing action groups (crags) help you reduce your carbon footprint.
Carpet: One green carpet option is made from fibers spun from recycled plastic soda bottles and is now commonly available. This carpet performs as good or better than carpet made from other materials, and costs about the same. The advantages include excellent stain resistance and durability and uses a material often thrown in the landfill; 500 square yards of carpet divert about 20,000 pop bottles from landfills. Carpet pad made from recycled fibers reduces the need for petrochemicals and off-gases less than a typical foam pad.
Carcinogen: Any substance that can cause or aggravate cancer.
Cellulose: The fibrous part of plants used in making paper and textiles. Most building products with the word cellulose imply that paper was used in the manufacture.
Cellulose Insulation: Insulation alternative to glass fiber insulation. Cellulose insulation is most often a mixture of waste paper and fire retardant, and has thermal properties often superior to glass fiber. Glass fiber batt insulation often contains formaldehyde, which can adversely affect indoor air quality and human health, and the glass fibers themselves are hazardous if inhaled and irritating to the skin and eyes. Specify cellulose insulation with high recycled content for maximum environmental benefit.
Cellulose insulation with borates: Cellulose insulation is made from recycled newspaper. The borates provide fire and vermin protection. Most cellulose insulation now uses chemical fire retardants as opposed to the natural borates. Environmentally sensitive persons should avoid cellulose insulation that contains newspaper ink, which can cause allergic reactions. There are cellulose insulation products made without inked newspaper.
Cementitious foam insulation: A magnesium-oxide based material blown with air to create an inert, effective insulation. It is especially good for people with chemical sensitivities.
Certified Lumber: General shorthand term for lumber that has been certified sustainable harvest by an independent certification authority. The underlying guidelines are for preservation of a diverse sustainable forest that exhibits the same ecological characteristics as a healthy natural forest. See Forest Stewardship Council.
Charrette: A meeting held early in the design phase of a project, in which the design team, contractors, end users, community stakeholders, and technical experts are brought together to develop goals, strategies, and ideas for maximizing the environmental performance of the project. Research and many projects’ experience has indicated that early involvement of all interested parties increases the likelihood that sustainable building will be incorporated as a serious objective of the project, and reduces the soft costs sometimes associated with a green design project.
Chiller: A device that generates a cold liquid that is circulated through an air-handling unit's cooling coil to cool the air supplied to the building.
Chlorofluorocarbons (CFCs): A family of inert, nontoxic, and easily liquefied chemicals used in refrigeration, air conditioning, packaging, insulation, or as solvents and aerosol propellants. Because CFCs are not destroyed in the lower atmosphere they drift into the upper atmosphere where their chlorine components destroy ozone. (See Ozone)
Cisterns: Cisterns are tanks used to store rainfall that has been collected from a roof or some other catchment area. They are usually located underground. The water is generally used for watering lawns and gardens, for washing cars and other similar uses, but can also be used for flushing toilets and, with treatment, for all other uses. Cisterns help conserve water and help prevent pollution of nearby streams from runoff.
Closed-loop Recycling - When a used product is recycled into a similar product; a recycling system in which a particular mass of material (possibly after upgrading) is remanufactured into the same product (e.g., glass bottles into glass bottles).
Commissioning (Building): The process of ensuring installed systems function as specified, performed by a third party
Commissioning Authority: Elements to be commissioned are identified, installation is observed, sampling is conducted, test procedures are devised and executed, staff training is verified, and operations and maintenance manuals are reviewed.
Compact Fluorescent Lamp (CFL): Small fluorescent lamps used as more efficient alternatives to incandescent lighting. Compared to incandescent lamps of the same luminous flux, CFLs use less energy and have a longer rated life. In the United States, a CFL can save over $30 in electricity costs over the lamp’s life-time compared to an incandescent lamp and save 2000 times their own weight in greenhouse gases. Using CFLs in place of incandescent light bulbs is no doubt the easiest and most cost effective way to save energy. Energy Star-qualified CFLs use approximately 75% less energy and last up to 10 times longer than traditional incandescent bulbs, saving users about $30 or more in energy costs over the length of its lifetime. Learn about Mercury and CFLs.
Composite materials: A complex material made up of two or more complementary substances. They can be difficult to recycle. Plastic laminates are an example. Composite materials are best applied in situations where they can be removed for reuse (not requiring remanufacture).
Composite Wood (also known as “Engineered Wood”)
This “man-made” wood is produced using adhesives to bind together the strands, particles, fibers or veneers of wood to form a composite product. This wood can be “green” when the wood fiber is provided by scrap or waste wood, when the adhesives are low or no VOC (link to “VOC”) and when the resulting product--often used for outdoor decks--eliminates the need for initial and periodic painting, staining or waterproofing. The substitution of vegetable fibers from potentially sustainable sources (e.g. rye, wheat and rice straw--for wood fibres can also result in a similar engineered “green” cellulosic product.Compost: The relatively stable humus material that is produced from a composting process in which bacteria in soil mixed with degradable materials break down the mixture into organic fertilizer. The process whereby organic wastes, including food wastes, paper and yard wastes, decompose naturally, resulting in a product rich in minerals and ideal for gardening and farming as a soil conditioner, mulch, resurfacing material or landfill cover.
Composting: Controlled biological decomposition of organic material in the presence of air to form a humus-like material. Controlled methods of composting include mechanical mixing and aerating, ventilating the materials by dropping them through a vertical series of aerated chambers, or placing the compost in piles out in the open air and mixing it or turning it periodically.
Compressed Natural Gas (CNG): An alternative fuel for motor vehicles; considered one of the cleanest because of low hydrocarbon emissions and its vapors are relatively non-ozone producing. However, vehicles fueled with CNG do emit a significant quantity of nitrogen oxides. 1
Conservation Easement: Easement restricting a landowner to land uses that are compatible with long-term conservation and environmental values.
Construction and Demolition Waste: Waste building materials, dredging materials, tree stumps, and rubble resulting from construction, remodeling, repair, and demolition of homes, commercial buildings and other structures and pavements. May contain lead, asbestos, or other hazardous substances.
Construction Site Recycling: See Construction Waste Management
Construction Waste Management: General term for strategies employed during construction and demolition to reduce the amount of waste and maximize reuse and recycling. Construction waste management is a sustainable building strategy in that it reduces the disposal of valuable resources, provides materials for reuse and recycling, and can promote community industries.
Cooling Load: See Building Cooling Load.
Cooling Tower: Device which dissipates the heat from water-cooled systems by spraying the water through streams of rapidly moving air. 1 Cooling towers can be substantial water users, and provide an opportunity for water conservation. Many local water providers can supply technical information on water use reduction and may provide incentives for measures with substantial water savings.
Countertops: The options for countertops made from renewable and recycled materials with low or no VOC (link to VOC) emissions are numerous and growing, including recycled glass, aluminum and paper products. There are also simple and attractive concrete counters (with fly-ash). In addition to looking for reclycled and/or renewable content, choose those that minimize energy usage and pollution in the extraction and/or manufacture and transportation. To find help picking a green countertop.
Cradle-to-Cradle: Recycling is an important aspect of many green products. Those products that are both made of recycled materials and also designed to be recycled at the end of their use are said to be “cradle-to-cradle” products—a concept popularized by the book of the same name by William McDonough and Michael Braungart.
Cradle-to-Grave: A term used in life-cycle analysis to describe the entire life of a material or product up to the point of disposal. Also refers to a system that handles a product from creation through disposal.
Cubic Feet Per Minute (CFM): A measure of the volume of a substance flowing through air within a fixed period of time. With regard to indoor air, refers to the amount of air, in cubic feet, that is exchanged with outdoor air in a minute's time; i.e., the air exchange rate.
Cullet: Crushed glass.
Daylighting: Using natural light in an interior space to substitute for artificial light. Daylighting is considered a sustainable building strategy in that it can reduce reliance on artificial light (and reduce energy use in the process) and when well designed, contributes to occupant comfort and performance. Common daylighting strategies include the proper orientation and placement of windows, use of light wells, light shafts or tubes, skylights, clerestory windows, light shelves, reflective surfaces, and shading, and the use of interior glazing to allow light into adjacent spaces. South-facing windows are most advantageous for daylighting and for moderating seasonal temperatures. They allow most winter sunlight into the home but little direct sun during the summer, especially when properly shaded. Learn more about Daylighting.
Deconstruction: - A process to carefully dismantle or remove useable materials from structures, as an alternative to demolition. It maximizes the recovery of valuable building materials for reuse and recycling and minimizes the amount of waste land-filled. Deconstruction options may include: Reusing the entire building by remodeling, moving the structure to a new location or taking the building apart to reuse lumber, windows, doors, and other materials.
Degree-Day: A rough measure used to estimate the amount of heating required in a given area; is defined as the difference between the mean daily temperature and 65 degrees Fahrenheit. Degree-days are also calculated to estimate cooling requirements.
Demand control ventilation: Ventilation provided in response to actual number of occupants and occupant activity.
Demand Hot Water System: Hot water heaters designed to provide instantaneous hot water, rather than storing preheated hot water in a tank. Such devices can serve an entire home, or be "point-of-use", serving an individual water use. Benefits include elimination of "standby losses", or energy wasted keeping stored water warm, and with point of use devices, reduction or elimination of water wasted waiting for water to get warm, as well as conductive losses as water travels through pipes. Electric demand systems tend to use a large amount of energy; gas-fired units with standing pilot lights lose much of their efficiency due to the ongoing pilot light.
Demand-side Waste Management: Prices whereby consumers use purchasing decisions to communicate to product manufacturers that they prefer environmentally sound products packaged with the least amount of waste, made from recycled or recyclable materials, and containing no hazardous substances.
Depressurization: A condition that occurs when the air pressure inside a structure is lower that the air pressure outdoors. Depressurization can occur when household appliances such as fireplaces or furnaces, that consume or exhaust house air, are not supplied with enough makeup air. Radon may be drawn into a house more rapidly under depressurized conditions. 1 Backdrafting of furnaces and vented appliances can also occur with depressurization, introducing exhaust gases into the house.
Dioxin: Any of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity as contaminants in commercial products. Tests on laboratory animals indicate that it is one of the more toxic anthropogenic (man-made) compounds.
Disassembly: Taking apart an assembled product. Design for disassembly in buildings allows building components to be readily reused and recycled.
Displacement Ventilation: Ventilation that uses natural convection processes to move warm air up and out of a volume. Displacement ventilation tends to use less energy than conventional forced air ventilation, as it works with natural convection processes.
Domestic hardwood: Deciduous trees that grow in the U.S.; this is the only type of wood in the U.S. where on a general scale the growth of new trees easily exceeds the removal rate.
Drought Tolerance: The capacity of a landscape plant to function well in drought conditions.
Durability: A factor that affects the life cycle performance of a material or assembly. All other factors being equal, the more durable item is environmentally preferable, as it means less frequent replacement. However, durability is rendered moot as a factor if the material is replaced for aesthetic reasons prior to it actually wearing out.
Dust spot efficiency: The dust spot efficiency test is a semi-quantitative measure of a filter’s collection efficiency for fine particles---those associated with smudging of the interior surfaces of buildings. Upstream and downstream paper target filters collect particles and the opacity (light transmission) is measured.
Dynamic Environmental Chamber: Well-controlled system (including temperature, relative humidity (RH) and air quality/purity) that utilizes realistic air flows for the assessment of chemical emissions from products and materials.
Earth sheltered design: Home design that is partially or totally below ground, either by digging into existing topography or filling over parts of the structure. Earth sheltered design uses the constant temperature of the soil to improve energy efficiency and can be beneficial for us on hilly sites to decrease maintenance and environmental impact.
Earth's thermal energy: A short distance below the surface, the Earth maintains a mostly constant temperature very close to the human comfort range. This can be used advantageously for geothermal heating systems.
Eco-Roof: See Green Roof.
Embodied Energy: The total amount of energy used to create a product, including energy expended in raw materials extraction, processing, manufacturing and transportation. Embodied energy is often used as a rough measure of the environmental impact of a product. Some product suppliers calculate embodied energy costs. Consumers may ask if they have made these calculations.
Emissions: The release of gases, liquids and/or solids from any process or industry. Liquid emissions are commonly referred to as effluents.
Encapsulation: The treatment of asbestos-containing material with a liquid that covers the surface with a protective coating or embeds fibers in an adhesive matrix to prevent their release into the air.
Endangered Species: Animals, birds, fish, plants, or other living organisms threatened with extinction by anthropogenic (man-caused) or other natural changes in their environment. Requirements for declaring a species endangered are contained in the Endangered Species Act.
Energy Analysis: Analysis of the energy use of a structure.
Energy Efficiency: Ways and technology that can reduce the amount of electricity or fuel used to do the same work. Such as keeping a house warm using less energy.
Energy Heel: The point at which typical roof rafters connect with the top plate of the exterior wall leaves little room for the full depth of attic insulation, creating compressed insulation and reduced performance. A raised heel truss, or "energy heel," raises the truss at that point (at least 6 inches) to allow the insulation enough room to produce its full R-value at this critical location.
Energy Management System: A control system capable of monitoring environmental and system loads and adjusting HVAC operations accordingly in order to conserve energy while maintaining comfort.
Energy Modeling: Process to determine the energy use of a building based on software analysis. Also called building energy simulation. Common simulation software are DOE-2 and Energy Plus. This is typically a computer model that analyzes the building’s energy-related features in order to project energy consumption of a given design.
Energy Recovery Ventilator (ERV): A mechanical device that draws stale air from the house and transfers the heat or coolness in that air to the air being pulled into the house. This can help reduce energy costs and dilute indoor pollutants. Energy Recovery Units use the heat in the building to preheat in the winter or cool air in the building during summer to chill the incoming outside air. Ultimately, they use less fossil fuel by saving electricity to warm or cool the air; therefore, the air is cleaner because there is less fossil fuel burned to make the electricity. And the incoming outside air promotes better indoor air quality.
Energy Star: Program administered by the Environmental Protection Agency and the U.S. Department of Energy that evaluates products based on energy efficiency. The Energy Star website contains valuable information on energy conservation and education (See http://www.energystar.gov)
Energy Star Products and Homes: ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy helping the public save money and protect the environment through energy efficient products and practices. New homes can earn the ENERGY STAR, as well as many household products, including large appliances. For a complete list of ENERGY STAR products
Energy Vampires: This term refers to electric appliances such as televisions, chargers, and clock radios that use energy even when turned off. The energy they use is also called a “phantom load.”
Engineered Wood: See “Composite Wood”
Engineered Lumber/Wood: Composite wood products made from lumber, fiber or veneer, and glue. Engineered wood products can be environmentally preferable to dimensional lumber, as they allow the use of waste wood and small diameter trees to produce structural building materials. Engineered wood products distribute the natural imperfections in wood fiber over the product, making them stronger than dimensional lumber. This allows for less material to be used in each piece, another environmental benefit. Potential environmental drawbacks with engineered wood include impacts on indoor environmental quality due to offgassing of chemicals present in binders and glues, and air and water pollution related to production.
Engineered Wood Products: Engineered wood products use smaller, younger trees, and parts of the tree that were not previously used, to reach the same or better structural characteristics of solid dimensional lumber. This makes better use of the resource and avoids the use of larger, older trees. The use of engineered wood products also eliminates the waste associated with warped, twisted or otherwise unusable lumber.
Environmental Footprint: For an industrial setting, this is a company's environmental impact determined by the amount of depletable raw materials and nonrenewable resources it consumes to make its products, and the quantity of wastes and emissions that are generated in the process. Traditionally, for a company to grow, the footprint had to get larger. Today, finding ways to reduce the environmental footprint is a priority for leading companies. An environmental footprint can be determined for a building, city, or nation as well, and gives an indication of the sustainability of the unit.
Environmental Impact Statement: A document required of federal agencies by the National Environmental Policy Act for major projects or legislative proposals significantly affecting the environment. A tool for decision making, it describes the positive and negative effects of the undertaking and cites alternative actions.
Environmental Restoration: The act of repairing damage to a site caused by human activity, industry or natural disasters. The ideal environmental restoration, though rarely achieved, is to restore the site as closely as possible to its natural condition before it was disturbed.
Environmentally Preferable Product: Products that have a lesser or reduced effect on human health and the environment when compared with competing products that serve the same purpose. The product comparison may consider raw materials acquisition, production, manufacturing, packaging, distribution, reuse, operation, maintenance, or disposal.
Environmentally Preferable Purchasing: Environmentally Preferable Purchasing is a United States federal-wide program (Executive Order 13101) that encourages and assists Executive agencies in the purchasing of Environmentally Preferable Products and services.
Erosion: The wearing away of land surface by wind or water, intensified by land-clearing practices related to farming, residential or industrial development, road building, or logging.
Exterior grade plywood: Uses phenol formaldehyde (a volatile organic compound) as an adhesive that is released in much smaller amounts compared to urea formaldehyde used in interior grade plywood and particleboard.
Faucets and Showerheads: New low flow and dual flow faucets and showerheads can save water, energy and money. Faucet aerators increase the spray velocity, producing a water stream similar to conventional faucets, but using significantly less water. Dual flow gives the user the options of a wide full force multiple steam spray, if needed, or a splash-free bubble stream which helps conserve water usage.
Flooring: There are a wide variety of natural, non-toxic green flooring from environmentally friendly and renewable resources; for natural wood products, look for those that are FSC certified or approved by international associations dedicated to socially responsible trade practices. Materials include bamboo, cork, and natural linoleums made of linseed, cork, tree rosin, limestone, and jute.
Fluorocarbons (FCs): Any of a number of organic compounds analogous to hydrocarbons in which one or more hydrogen atoms are replaced by fluorine. Once used in the United States as a propellant for domestic aerosols, they are now found mainly in coolants and some industrial processes. FCs containing chlorine are called chlorofluorocarbons (CFCs). They are believed to be modifying the ozone layer in the stratosphere, thereby allowing more harmful solar radiation to reach the Earth's surface.
Flush-Out: A period after finish work and prior to occupation that allows the building’s materials to cure and release volatile compounds and other toxins. A building flush-out procedure is normally followed, with specified time periods, ventilation rate, and other criteria.
Fly Ash: A fine, glass-powder recovered from the gases of burning coal during the production of electricity. It is an ash residue from high temperature combustion processes. Electric motor plants using western coal produce a non-toxic fly ash that because of its very high calcium content can be a substitute for Portland Cement (the common bonding material in concrete) and these micron-sized earth elements consist primarily of silica, alumina and iron. When mixed with lime and water the fly ash forms a cementitious compound with properties very similar to that of portland cement. Because of this similarity, fly ash can be used to replace a portion of cement in the concrete, providing some distinct quality advantages. The concrete is denser resulting in a tighter, smoother surface with less bleeding. Fly ash concrete offers a distinct architectural benefit with improved textural consistency and sharper detail. Fly ash with a low LOI (carbon content) is used as a substitute for portland cement in concrete. Regulations vary from state to state, however, ASTM suggests that fly ash must not contain more than 6% unburned carbon to be used for its cementitious qualities. Otherwise, concrete companies use it as a fine aggregate in concrete block. Others use it for filling old coal mines, seaside docking areas and as a lining for hazardous waste dumps. Substitution of fly ash for portland cement in concrete is considered a sustainable building strategy, as it reduces the amount of energy-intensive (and CO2-producing) cement in the mix, as well as providing the performance enhancements described above.
Footprint (Building): The area of a building formed by the perimeter of the foundation. Shrinking the footprint of a building allows for more open space and pervious surface on a site.
Footprint (Environmental): See Environmental Footprint
Forest Stewardship Council FSC: A third-party certification organization, evaluating the sustainability of forest products. FSC-certified wood products have met specific criteria in areas such as forest management, labor conditions, and fair trade. FSC devoted to encouraging the responsible management of the world’s forests. FSC sets high standards that ensure forestry is practiced in an environmentally responsible, socially beneficial, and economically viable way. Landowners and companies that sell timber or forest products seek FSC certification as a way to verify to consumers that they have practiced forestry consistent with FSC standards. For more information click here.
Formaldehyde: A colorless, pungent, and irritating gas, CH20, used chiefly as a disinfectant and preservative and in synthesizing other compounds like resins. It is used as an adhering component of glues in many wood products. It can cause respiratory problems, cancer, and chemical sensitivity.
Fossil fuel: Fuel, such as coal, oil and natural gas, produced by the decomposition of ancient (fossilized) plants and animals.
Fuel cell: A technology that uses an electrochemical process to convert energy into electrical power. Often powered by natural gas, fuel cell power is cleaner than grid-connected power sources. In addition, hot water is produced as a by-product that can be utilized as a thermal resource for the building. Hydrogen can be the principal fuel for fuel cells, but the challenge is economically and efficiently producing the hydrogen to drive the fuel cell. If this challenge could be met, it would prompt a revolution in power production.
Full spectrum lights: These lights come closer to the natural light spectrum and are considered more healthy.
Fungus (Fungi): Molds, mildews, yeasts, mushrooms, and puffballs, a group of organisms lacking in chlorophyll (i.e., are not photosynthetic) and which are usually non-mobile, filamentous, and multicellular. Some grow in soil, others attach themselves to decaying trees and other plants whence they obtain nutrients. Some are pathogens; others stabilize sewage and digest composted waste.
Geothermal heat exchange technology: In winter, geothermal heat exchange technology utilizes heat from subsurface water and soils to heat buildings; in summer, this technology extracts heat from the building into subsurface water and soils for cooling. This is at the mechanism of Geothermal Ground-Source Heat Pumps.
Geothermal/Ground Source Heat Pump: These heat pumps are underground coils to transfer heat from the ground to the inside of a building. (See: heat pump; water source heat pump) This type of heat pump can realize substantial energy savings over conventional heat pumps, by using the naturally more stable temperature of the earth as its heat source.
Global Warming: An increase in the near surface temperature of the earth. Global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased emissions of greenhouse gases. Scientists generally agree that the earth's surface has warmed by about 1 degree Fahrenheit in the past 140 years. The Intergovernmental Panel on Climate Change (IPCC) recently concluded that increased concentrations of greenhouse gases are causing an increase in the earth's surface temperature and that increased concentrations of sulfate aerosols have led to relative cooling in some regions, generally over and downwind of heavily industrialized areas.
Glazing: Translucent or transparent element of a window assembly. Glazing can have properties that increase its thermal performance, including Low-Emissivity coatings, multiple panes, thermally broken spacers, etc.
Global Warming Potential: The ratio of the warming caused by a substance to the warming caused by a similar mass of carbon dioxide. CFC-12, for example, has a GWP of 8,500, while water has a GWP of zero.
Gray Water: Domestic wastewater composed of wash water from kitchen, bathroom, and laundry sinks, tubs, and washers, and which does not contain sewage or fecal contamination, and which can be reused for irrigation after simple filtration.
Gray Water Reuse: A strategy for reducing wastewater outputs from a building, by diverting the gray water into productive uses such as subsurface irrigation, or on-site treatment and use for non-potable functions such as toilet flushing. Gray water reuse is restricted in many jurisdictions; check with local health and building officials.
“Green” building: A common term in use today, but a generic term in use, that generally means building techniques and technologies that seek to emphasize energy efficiency and resource management. The emphasis is on "Sustainability", which means meeting our present needs without compromising the needs of future generations and seeking to minimize the adverse impacts of building practices while seeking to promote the health of building processes on human health. Sustainability implies that we look at and understand our local environment in terms of climate, natural resources, and human resources and improve our relationship with them without jeopardizing their future usefulness. Recognizing the nature of the interdependence of the human and natural environment is a key concept toward understanding sustainability.
Green Design: A design, usually architectural, conforming to environmentally sound principles of building, material and energy use. A green building, for example, might make use of solar panels, skylights and recycled building materials.
Green Label: A certification program by the Carpet and Rug Institute for carpet and adhesives meeting specified criteria for release of volatile compounds.
Green Roof: Contained green space on, or integrated with, a building roof. Green roofs maintain living plants in a growing medium on top of a membrane and drainage system. Green roofs are considered a sustainable building strategy in that they have the capacity to reduce stormwater runoff from a site, they modulate temperatures in and around the building, have thermal insulating properties, can provide habitat for wildlife and open space for humans, and other benefits.
Greenhouse Effect: The warming of the Earth's atmosphere attributed to a buildup of carbon dioxide or other gases; some scientists think that this build-up allows the sun's rays to heat the Earth, while making the infra-red radiation atmosphere opaque to infra-red radiation, thereby preventing a counterbalancing loss of heat. Vapors such as water, ozone, carbon dioxide, carbon monoxide, methane and nitrous oxide that reflect solar radiation back to Earth and are linked to global warming; sources include forest fires, gasoline-fueled cars, coal-fired power plants and natural gas flares.
GreenGuard: GreenGuard Environmental Institute (GEI) has established performance based standards to define goods with low chemical and particle emissions for use indoors, including building materials, interior furnishings, furniture, cleaning and maintenance products. The standard establishes certification procedures including test methods, allowable emissions levels, product sample collection and handling, testing type and frequency, and program application processes and acceptance. For more information about GEI
Greenhouse Gas: A gas, such as carbon dioxide or methane, which contributes to potential climate change.
Greenwash: Disinformation disseminated by an organization so as to present an environmentally responsible public image.
Grey Water Systems: Greywater is washwater, i.e. all wastewater excepting toilet wastes and food wastes derived from garbage grinders. (Toilet wastewater is called "blackwater"). To conserve water, greywater can be captured and used without treatment for irrigation and for flushing toilets. It is also possible to treat greywater for reuse as potable water, although cost is frequently prohibitive. To learn more about Greywater
Ground Cover: Low-growing plants often grown to keep soil from eroding and to discourage weeds.
Halogen: A type of incandescent lamp with higher energy-efficiency that standard ones.
Halon: Bromine-containing compounds with long atmospheric lifetimes whose breakdown in the stratosphere causes depletion of ozone. Halons are used in firefighting.
Harvested rainwater: The rain that falls on a roof and is channeled by gutters to a storage tank or cistern. The uses of this water are dependent on any pollutants that may be picked up from the roof surface and atmospheric pollutants.
Heat Exchanger: Device for exchanging heat present in wastewater or stale air to preheat incoming water or air. See Heat Recovery Ventilator for more information on air-to-air heat exchangers.
Heat Island Effect: A "dome" of elevated temperatures over an urban area caused by structural and pavement heat fluxes, and pollutant emissions.
Heat Pump: An electric device with both heating and cooling capabilities. It extracts heat from one medium at a lower (the heat source) temperature and transfers it to another at a higher temperature (the heat sink), thereby cooling the first and warming the second. (See: geothermal, water source heat pump.)
Heat Pumps: For climates with moderate heating and cooling needs, heat pumps offer an energy-efficient alternative to furnaces and air conditioners. In heating, ventilation, and cooling applications, a heat pump normally refers to a vapor-compression refrigeration device that includes a reversing valve and optimized heat exchangers so that the direction of heat flow may be reversed. Most commonly, heat pumps draw heat from the air or from the ground. Because they move heat rather than generate heat, heat pumps can significantly reduce energy costs. Air-source, ductless mini-split, geothermal and absorption are some of the varieties of heat pumps available today for use in homes. Read more about heat pumps. To check out City Utility rebates for heat pumps.
Heat Recovery Unit/Ventilator: An air-to-air heat exchanger with balanced exhaust and supply fans that meet all necessary ventilation needs without producing drafts or air pressure imbalance on a heating or cooling system. These building mechanical systems capture waste heat from another system and use it to replace heat that would otherwise come from a primary energy source.
Heat Recovery Ventilation: To reduce energy costs, new homes have been built to be airtight when doors and windows are closed. But indoor air quality can be compromised by pollutants and moisture and emissions without sufficient ventilation. Heat recovery ventilators solve this problem by using a heat-exchanger to tranfer heat from outgoing heated indoor air to incoming fresh air without mixing the airstreams. The heat-exchange core of a typical HRV is made up of thin aluminum passages with incoming and outgoing airstreams flowing in alternate passages. To see a diagram
Heavy Metals: Metallic elements with high atomic weights; (e.g., mercury, chromium, cadmium, arsenic, and lead); can damage living things at low concentrations and tend to accumulate in the food chain.
HiEff RTU's: High Efficiency Rooftop Units are air conditioning units that utilize a higher Annual Fuel Utilization (AFU) rating.
High Efficiency: General term for technologies and processes that require less energy, water, or other inputs to operate. A goal in sustainable building is to achieve high efficiency in resource use when compared to conventional practice. Setting specific targets in efficiency for systems (e.g., using only EPA Energy Star certified equipment, furnaces with an AFUE rating above 90%, etc.) and designs (e.g., watts per square foot targets for lighting) help put this general goal of efficiency into practice.
High-Heeled Truss: Roof truss design that allows space for insulation near the eaves. Conventional truss design limits the amount of insulation that can be applied in this area.
High Intensity Discharge: A generic term for mercury vapor, metal halide, and high-pressure sodium lamps and fixtures.
High Performance Glazing: Generic term for glazing materials with increased thermal efficiency.
High quality duct system: This option avoids the potential of significant heating and cooling losses, as well as avoiding potential health threats caused by depressurizing or pressurizing a house. All ducts are sealed using a fibrated latex mastic and fiberglass tape. Inner and outer linings of the duct are both sealed. The air handler, support platform and return plenum are sealed air tight at the joints. Duct tape is not used in any part of the system. No ductwork is run inside of the building envelope walls. The system can be performance tested to ensure proper installation.
Home Energy Audit: A home energy audit provides information on the need for, cost and associated savings of energy improvements in your home or building. Springfield City Utilities and some local Electric Co-ops pay up to half of the cost of home audits (currently around $100). A home energy audit is recommended prior to upgrading insulation or windows. Qualified home energy auditors (link to “home energy auditors” on “Local Resources” page) in Missouri are certified by the Department of Natural Resources.
Household Hazardous Waste: Hazardous products used and disposed of by residential as opposed to industrial consumers. Includes paints, stains, varnishes, solvents, pesticides, and other materials or products containing volatile chemicals that can catch fire, react or explode, or that are corrosive or toxic.
HVAC (Heating, Ventilation, and Air Conditioning): General term for the heating, ventilation and air conditioning system in a building. System efficiency and design impact the overall energy performance of a home and its indoor environmental quality.
Hydrocarbons (HC): Chemical compounds that consist entirely of carbon and hydrogen.
Hydrochlorofluorocarbon (HCFC): HCFCs are generally less detrimental to depletion of stratospheric ozone than chlorofluorocarbons. HCFCs are generally used to replace CFC’s where mandates require CFC’s to be eliminated. A total ban on all CFC’s and HCFCs is scheduled effective 2030.
Hydrologic Cycle: Movement or exchange of water between the atmosphere and earth.
Hydrology: The science dealing with the properties, distribution, and circulation of water.
Hydrolysis: The decomposition of organic compounds by interaction with water.
Hydronic Heating (Hydronic System): A space heating system that uses water circulated through a radiant floor or baseboard system or a convection or fan coil system.
Hypersensitivity Diseases: Diseases characterized by allergic responses to pollutants; diseases most clearly associated with indoor air quality are asthma, rhinitis, and pneumonic hypersensitivity.
ICF—Insulating Concrete Form: These large, hollow blocks are stacked right off of the truck and filled with reinforcing steel (rebars) and concrete. The end result is an energy efficient wall that is structurally sound, insulated, strapped, has a vapor barrier and ready for a final exterior and interior finish. Learn more about ICF
Impervious Surface: A surface that sheds the precipitation falling on it, rather than infiltrating. Impervious surfaces can lead to excessive stormwater runoff and limit the amount of stormwater that remains onsite or recharges local aquifers.
Indigenous materials: To reduce transportation cost and increase viability of the local economy, building materials that are mined, manufactured or fabricated in an area close to where building will take place is always preferred.
Indigenous Planting: Landscaping strategy that uses native plants. Provided the natives are placed in the proper growing conditions; such plantings can have low, or zero supplemental water needs.
Indoor Air Pollution: Chemical, physical, or biological contaminants in indoor air.
Indoor Air Quality (IAQ): ASHRAE defines acceptable indoor air quality as air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which 80% or more people exposed do not express dissatisfaction. Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. These include any form of combustion—smoking, furnaces, stoves--, products for cleaning, personal care, and hobbies, air fresheners, many building materials, furnishings, carpets, pesticides, and many more. Inadequate ventilation can increase indoor pollutant levels by failing to bring in enough outdoor air to dilute the emissions inside and by not carrying indoor air pollutants out of the home. To learn more visit EPA An Introduction to Indoor Air Quality or ToolBase Services IAQ
Infiltration: a. The penetration of water through the ground surface into sub-surface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls. b. The technique of applying large volumes of waste water to land to penetrate the surface and percolate through the underlying soil.
Infiltration Rate: The quantity of water that can enter the soil in a specified time interval.
Inflow: Entry of extraneous rain water into a sewer system from sources other than infiltration, such as basement drains, manholes, storm drains, and street washing.
Insulated Concrete Form: Expanded polystyrene forms that are left in place after the concrete is poured for a foundation or wall. The foam increases the thermal performance of the structure over non-insulated concrete.
Insulation: Improving the insulation in any building is probably the single most cost effective way to reduce energy usage. Look for products with a large percentage of recycled content and prefer blown-in products or the installation of batts, which typically decreases the opportunity for air leakage. Typical insulation levels are R-15 in the walls, R-38 in the attic, and R-11 on basement walls. Both City Utilities and the State of Missouri offer help with costs. Learn more about insulation
Integrated Pest Management (IPM): A mixture of chemical and other, non-pesticide, methods to control pests.
Integrated Waste Management: The complementary use of a variety of practices to handle solid waste safely and effectively. Techniques include source reduction, recycling, composting, combustion and landfilling.
Integration: An essential concept in sustainable building. Viewing a building as a system allows the discovery of synergies and potential tradeoffs or pitfalls with design choices. An integrated design approach helps maximize synergies and minimize unintended consequences.
Joint and Several Liability: Under CERCLA, this legal concept relates to the liability for Superfund site cleanup and other costs on the part of more than one potentially responsible party (i.e., if there were several owners or users of a site that became contaminated over the years, they could all be considered potentially liable for cleaning up the site).
Kilowatt-hour: 1 kWh equals 10 100-watt bulbs all burning at the same time for one hour. Also called a measure of electric usage equivalent to the use of 1,000 watts for one hour. A kilowatt-hour (kWh) is the standard metric unit of measurement for electricity. The average home in the United States uses approximately 900 kWh/month or 10.8 MWh/year of electricity. One kilowatt-hour (kW) is equal to 1,000 watt-hours (Wh). One megawatt-hour (MWh) is equal to 1,000 kilowatt-hours. A watt-hour is the amount of energy delivered at a rate of one watt (W) for a period of one hour. One watt is the amount of power rate of one joule of work per second of time. • Example: A 100 watt light bulb in use for 10 hours uses 1000 watt-hours, or 1 kilowatt of electricity. (100 watts x 10 hours = 1000 watt-hours = 1 kWh). A “Megawatt-hour” is equal to 1,000 kWh.
Kitchen recycling center: A built-in section of the kitchen cabinetry that allows convenient separation of recyclable materials.
Leachate: Water that collects contaminants as it trickles through wastes, pesticides or fertilizers. Leaching may occur in farming areas, feedlots, and landfills, and may result in hazardous substances entering surface water, ground water, or soil.
Lead (Pb): A heavy metal that is hazardous to health if breathed or swallowed. Its use in gasoline, paints, and plumbing compounds has been sharply restricted or eliminated by federal laws and regulations. Older homes frequently have lead-based paints and it was also found in lead solder used in plumbing before l978. Lead is toxic to many organs and can cause serious damage to the brain, kidneys and nervous system. It is particularly harmful to fetuses and infants due to their developing neurological systems.
LEED™ Leadership in Energy and Environmental Design (LEED) - A self-assessing green building rating system developed by the U.S. Green Building Council. LEED™ stands for Leadership in Energy and Environmental Design, and evaluates a building from a systems perspective. LEED is the nationally accepted benchmark for the design, construction, and operation of high performance green buildings. By achieving points in different areas of environmental performance, a building achieves a level of "certification" under the system. Existing and new buildings can earn certified, silver, gold or platinum ratings. LEED is designed for rating new and existing commercial, institutional, and high-rise residential buildings, however, a residential LEED standard is being developed as well. It evaluates environmental performance from a "whole building" perspective over a building's life cycle, providing a definitive standard for what constitutes a green building. LEED gives building owners and operators the tools they need to have an immediate and measurable impact on their buildings’ performance. LEED promotes a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality. Currently, LEED is primarily a standard for commercial construction, but a residential standard is being developed.
Life Cycle (of a Product): All stages of a product's development, from extraction of fuel for power to production, marketing, use, and disposal.
Life Cycle Analysis (LCA): The assessment of a product's full environmental costs, from raw material to final disposal, in terms of its extraction costs, transportation, manufacturing, consumption, use and disposal throughout its lifetime Life cycle analysis is used as a tool for evaluating the relative performance of building materials, technologies. The life cycle cost is the amortized annual cost of a product, including capital costs, installation costs, operating costs, maintenance costs, and disposal costs discounted over the lifetime of a product.
Life Cycle Inventory (LCI): An accounting of the energy and waste associated with the creation of a new product through use and disposal.
Light-Emitting Diode (LED): A long-lasting illumination technology used for exit signs which requires very little power.
Light Shelf: A horizontal shelf positioned (usually above eye level) to reflect daylight onto the ceiling and to shield direct flare from the sky.
Linoleum: A resilient flooring product developed in the 1800s, manufactured from cork flour, linseed oil, oak dust, and jute. Linoleum’s durability, renewable inputs, anti-static properties, and easy-to-clean surface often make it classified as a "green" building material.
Local/Regional Materials: Building products manufactured and/or extracted within a defined radius of the building site. For example, the US Green Building Council defines local materials as those that are manufactured, processed and/or extracted within a 500-mile radius of the site. Use of regional materials is considered a sustainable building strategy due to the fact that these materials require less transport, reducing transportation-related environmental impacts. Additionally, regional materials support local economies, supporting the community goal of sustainable building.
Low biocide: Many paints have added fungicides and pesticides. A low-biocide paint does not include such additives.
Low Emissivity (low-E) Windows: Window technology that lowers the amount of energy loss through windows by inhibiting the transmission of radiant heat while still allowing sufficient light to pass through. “Low-E” (low emissivity) windows reflect heat, not light, and therefore keep spaces warmer in winter and cooler in summer
Low Impact Development: Low Impact Development (LID) is an innovative stormwater management approach with a basic principle that is modeled after nature, using design techniques that infiltrate, filter, store, evaporate, and detain runoff close to its source. Maximizing open space and use of rain barrels, rain gardens, cisterns, pervious concrete and bioswales are just some of the methods used to retain rainwater on site, thereby preventing pollution of nearby streams from excessive runoff.
Low pressure drop high efficiency air filters: Extended surface pleated air filters that allow greater air filtration without a significant increase in horsepower requirements.
Low Toxic: Generic term for products with lower levels of hazard than conventional products. Specific criteria need to be applied to this term to make it meaningful in the selection of sustainable building materials.
Low VOC: Building materials and finishes that exhibit low levels of "offgassing," the process by which VOCs (Volatile Organic Compounds) are released from the material, impacting health and comfort indoors and producing smog outdoors. Low (or zero) VOC is an attribute to look for in an environmentally preferable building material or finish. See "Volatile Organic Compound (VOC)" for more information.
Lumber: A number of recycled-content and composite material deck products are currently on the market. An attractive alternative to chemically treated wood and valuable naturally-durable woods like redwood and cedar, recycled-content and composite material decks are very low-maintenance and highly durable. These products are made either entirely or partially from recycled plastic, which helps close the recycling loop by finding useful end products for recycled materials. When lumber is used that is not recycled-content or composite material, both LEED and NAHB’s Green Home Building Guidelines include limitations on what lumber is allowed and how is to be harvested.
Maintenance: An overlooked element of a product, system, or design strategy that impacts cost over the life cycle. Selecting products and designing for easy maintenance enhances durability and lessens the likelihood that maintenance is overlooked. Establishing and adhering to a maintenance protocol ensures that materials and systems function to specifications.
Manual: See Operations Manual
Material Safety Data Sheet (MSDS): A compilation of information required under the OSHA Communication Standard on the identity of hazardous chemicals, health, and physical hazards, exposure limits, and precautions. Section 311 of SARA requires facilities to submit MSDSs under certain circumstances. The MSDS forms contain brief information regarding chemical and physical hazards, health effects, proper handling, storage, and personal protection appropriate for use of a particular chemical in an occupational environment.
MDF (Medium Density Fiberboard): A composite wood fiberboard, used for cabinetry and other interior applications. MDF containing urea formaldehyde can contribute to poor indoor air quality.
Mercury: A metal that is an odorless silver liquid at room temperature, converting to an odorless, colorless gas when heated. Mercury readily combines with other elements, and accumulates in the environment. Mercury is toxic, and causes a range of neurological, organ, and developmental problems. Fluorescent lights and old thermostats are two building related products that can contain significant amounts of mercury. Newer fluorescent lights are available with substantially reduced amounts of mercury.
Methane: A colorless, nonpoisonous, flammable gas created by anaerobic decomposition of organic compounds. A major component of natural gas used in the home. Methane has also been found to be a potent greenhouse gas. Methane from landfills, livestock, and composting operations can be captured and used as a fuel source for alternative energy production.
Modular Building: Building technique using modular, or pre-constructed components. Building on a "module" also refers to the concept of using standardized dimensions that reduce the amount of construction waste. Building in four-foot increments is one strategy.
Motion Sensors: Installing motion sensors for lights, particularly those installed outdoors, improves energy consumption because lights are only on when they are needed – and off when they’re not.
Montreal Protocol: Treaty, signed in 1987, governs stratospheric ozone protection and research, and the production and use of ozone-depleting substances. It provides for the end of production of ozone-depleting substances such as CFCs. Under the Protocol, various research groups continue to assess the ozone layer. The Multilateral Fund provides resources to developing nations to promote the transition to ozone-safe technologies.
Mulch: A layer of material (wood chips, straw, leaves, etc.) placed around plants to hold moisture, prevent weed growth, and enrich or sterilize the soil.
Multiple Chemical Sensitivity: A diagnostic label for people who suffer multi-system illnesses as a result of contact with, or proximity to, a variety of airborne agents and other substances.
National Association of Home Builders (NAHB) Green Home Building Guidelines: A third party verified program for single-family construction, remodeling and multifamily construction. Divided into two parts, the Guidelines cover seven areas, or guiding principles: Lot Design; Resource Efficiency; Energy Efficiency; Water Efficiency, Indoor Environmental Quality; Homeowner Education; and Global Impact. There are three levels of green building available to builders to rate their projects– Bronze, Silver, and Gold.
Native Plants: Native plants—plants that grow locally in the wild—are preferred for use in green landscaping. These plants are adapted to the local conditions and will have lower need for soil amendments, watering and fertilizing. And, since they have evolved locally, many will produce nectar, seeds and fruits that will attract and help support the native birds, butterflies and other wildlife in the area. Plants are best selected from local native plant nurseries to guarantee the best adaptation to local conditions.
Natural Ventilation: Ventilation design that uses existing air currents on a site and natural convection to move and distribute air through a structure or space. Strategies include placement and operability of windows and doors, thermal chimneys, landscape berms to direct airflow on a site, and operable skylights.
Net Metering: A method of crediting customers for electricity that they generate on site in excess of their own electricity consumption. Customers with their own generation offset the electricity they would have purchased from their utility. If such customers generate more than they use in a billing period, their electric meter turns backwards to indicate their net excess generation. Missouri has a net metering law requiring the utility to purchase surplus power generated by local consumer based systems.
Night Flushing: The process of removing hot air from a building during the cool evening hours, to cool elements with thermal mass within the building and flush stale air.
Nitrogen oxide: (NO) A colorless, poisonous gas. It is a by-product of gas combustion.
Nonrenewable Energy: Energy derived from depletable fuels (oil, gas, coal) created through lengthy geological processes and existing in limited quantities on the earth.
Nonrenewable Resource: A resource that cannot be replaced in the environment (e.g., fossil fuels) because it forms at a rate far slower than its consumption.
Occupancy Sensor: A sensing device, commonly connected to a room’s lighting but also occasionally to heating or ventilation, that shuts down these services when the space is unoccupied.
Offgassing: Release of volatile chemicals from a product or assembly. Many chemicals released from materials impact indoor air quality and occupant health and comfort. Offgassing can be reduced by specifying materials that are low- or no-VOC and by avoiding certain chemicals (e.g., urea formaldehyde) entirely. Controlling indoor moisture, and specifying pre-finished materials, can also reduce offgas potential.
On-Demand Hot Water: See Demand Hot Water Systems
On-Site Stormwater Management: Building and landscape strategies to control and limit stormwater pollution and runoff. Usually an integrated package of strategies, elements can include vegetated roofs, compost-amended soils, pervious paving, tree planting, drainage swales, and more.
Operations Manual (O&M Manual): Manual developed to assist building occupants in maintaining and operating a green building and its features. Many features’ effectiveness can be reduced or eliminated by the actions (or inaction) of occupants and maintenance crews. An operations manual usually includes product and system information and warranties, contact information, and other information required for effective operations and maintenance.
Organic Compound: Vast array of substances typically characterized as principally carbon and hydrogen, but that may also contain oxygen, nitrogen and a variety of other elements as structural building blocks.
Orientation (Solar): Orientation of a structure for controlled solar gain is essential to the success of passive and active solar design elements. Sun charts and software assist in orienting a building for maximum solar benefit. Designing for solar considerations can substantially reduce both heating and cooling.
OSB: Oriented Strand Board. A high strength, structural wood panel formed by binding wood strands with resin in opposing orientations. OSB is environmentally beneficial in that it uses small dimension and waste wood for its fiber; however, resin type should be considered for human health impact, and the production process monitored for air pollutant emissions.
Outgas: The emitting of fumes into the air; there are numerous building materials that have chemicals in them which outgas over time, particularly when exposed to high temperatures, moisture and/or ozone levels.
Overhangs: Architectural elements on roofs and above windows that function to protect the structure from the elements or to assist in daylighting and control of unwanted solar gain. Sizing of overhangs should consider their purpose, especially related to solar control.
Ozone (O3): Ozone is a molecule consisting of three bound oxygen atoms, which is only formed naturally in very small amounts in nature by lighting bolts. It is a vital component for life on Earth. Without it, scientists suggest that only life in the sea could exist over time. Ozone captures and reflects harmful ultraviolet radiation from the sun which is lethal to life on the planet. It has taken billions of years for the ozone layer to form. Ozone can also be produced by man-made processes, including smog from the burning of fossil fuels, however it takes hundreds of years for ozone to migrate from ground level to the stratosphere where it is normally located given its molecular weight. The stratosphere is approximately 7-10 miles above the earth. Ground level ozone is produced near the earth’s surface through complex chemical reactions of nitrogen oxides, volatile organic compounds, and sunlight. Ground level ozone is the primary component of smog and is harmful to humans and the environment.
Ozone Depletion: Destruction of the earth's ozone layer, which can be caused by the photolytic breakdown of certain chlorine- and/or bromine-containing compounds (e.g., chlorofluorocarbons), which catalytically decompose ozone molecules.
Ozone Hole: A thinning break in the ozone layer. Designation of amount of such depletion as an "ozone hole" is made when the detected amount of depletion exceeds 50 percent. Seasonal ozone holes have been observed over the Antarctic and arctic regions, part of Canada, and the extreme northeastern United States.
Ozone Layer: The protective layer in the atmosphere, about 12-15 miles above sea level, that absorbs some of the sun's ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the earth's surface.
Ozone (O3): A naturally occurring, highly reactive, irritating gas comprising triatomic oxygen formed by recombination of oxygen in the presence of ultraviolet radiation. This gas builds up in the lower atmosphere as smog pollution, while in the upper atmosphere it forms a protective layer that shields the earth and its inhabitants from excessive exposure to damaging ultraviolet radiation.
Pathogens: Microorganisms (e.g., bacteria, viruses, or parasites) that can cause disease in humans, animals and plants.
Particulate Pollution: Pollution made up of small liquid or solid particles suspended in the atmosphere or water supply.
Passive cooling: The building's structure (or an element of it) is designed to permit increased ventilation and retention of coolness within the building components. The intention is to minimize or eliminate the need for mechanical means of cooling.
Passive design: In home construction, the building design and placement permits the use of natural processes such as radiation, convection, absorption, and conduction to support comfort levels.
Passive heating: The building's structure (or an element of it) is designed to allow natural thermal energy flows such as radiation, conduction, and natural convection generated by the sun to provide heat. The home relies solely or primarily on non-mechanical means of heating.
Passive solar water heater: A water heating system that does not require mechanical pumps or controls to create hot water for domestic use.
Passive Solar: Strategies for using the sun’s energy to heat (or cool) a space, mass, or liquid. Passive solar strategies use no pumps or controls to function. A window, oriented for solar gain and coupled with massing for thermal storage (e.g., a Trombe wall) is an example of a passive solar technique.
pH: An expression of the intensity of the basic or acid condition of a liquid; may range from 0 to 14, where 0 is the most acid and 7 is neutral. Natural waters usually have a pH between 6.5 and 8.5.Passive ventilation: Passive ventilation relies typically on using both convective air flows that result from the tendency of warm air to rise and cool air to sink and taking advantage of prevailing winds. Many passive ventilation systems rely on the building users to control window and vents as indicated by site conditions and conditions within the building.
Pervious paving: Paving material that allows water to penetrate to the soil below; this reduces the amount of water that needs to be treated by the water system and increases the water in the aquifer.
Photocell: A device that measures the amount of incident light present in a space.
Photovoltaic (PV) Cell: An electronic device consisting of layers of semiconductor materials fabricated to form a junction (adjacent layers of materials with different electronic characteristics) and electrical contacts and being capable of converting incident light directly into electricity (direct current).
Photovoltaic panels (PVs): Photovoltaic devices use semiconductor material to directly convert sunlight into electricity. Power is produced when sunlight strikes the semiconductor material and creates an electrical current.
Phytoremediation: Low-cost option for site cleanup when the site has low levels of contamination that are widely dispersed. Phytoremediation (a subset of bioremediation) uses plants to break down or uptake contaminants.
Pollution: Generally, the presence of a substance in the environment that, because of its chemical composition or quantity, prevents the functioning of natural processes and produces undesirable environmental and health effects. Under the Clean Water Act, for example, the term has been defined as the man-made or man-induced alteration of the physical, biological, chemical and radiological integrity of water and other media.
Pollution Prevention: Techniques that eliminate waste prior to treatment, such as changing ingredients in a chemical reaction. Identifying areas, processes and activities that create excessive waste products or pollutants in order to reduce or prevent them through alteration or elimination of a process. The EPA has initiated a number of voluntary programs in which industrial or commercial "partners" join with the EPA in promoting activities that conserve energy, conserve and protect the water supply, reduce emissions or find ways of utilizing them as energy resources, and reduce the waste stream.
Porous Paving: Paving surfaces designed to allow stormwater infiltration and reduce runoff.
Post-Consumer Recycling: Use of materials generated from residential and consumer waste for new or similar purposes; e.g. converting wastepaper from offices into corrugated boxes or newsprint.
Post-Consumer Recycle Content: A product composition that contains some percentage of material that has been reclaimed from the same or another end use at the end of its former, useful life.
Post-Industrial Material: Industrial manufacturing scrap or waste; also called pre-consumer material.
Post-Industrial Recycle Content: A product composition that contains some percentage of manufacturing waste material that has been reclaimed from a process generating the same or a similar product. Also called pre-consumer recycle content.
Precautionary Principle: When information about potential risks is incomplete, basing decisions about the best ways to manage or reduce risks on a preference for avoiding unnecessary health risks instead of on unnecessary economic expenditures.
Pre-Consumer Materials/Waste: Materials generated in manufacturing and converting processes such as manufacturing scrap and trimmings and cuttings. Includes print overruns, overissue publications, and obsolete inventories. Pre-consumer material is material diverted from the waste stream following an industrial process, excluding reutilization of materials such as rework, regrind or scrap generated in a process and capable of being reclaimed within the same process. Synonyms include post-industrial and secondary material.
Programmable Thermostats: You can save around 10% a year on your heating and cooling bills by simply turning your thermostat back 10°–15° for eight hours. You can do this most easily by installing an automatic setback or programmable thermostat, which allows you to adjust the times you turn on the heating or air-conditioning according to a pre-set schedule. To learn about a City Utilities rebate
Pyrolysis: Decomposition of a chemical by extreme heat.
Radiant Barriers: Radiant barriers are installed in homes—most commonly in attics—to keep them cooler and reduce cooling costs. In hot climates, the benefits of a radiant barrier include both dollar savings and increased comfort. The barrier consists of a highly reflective material that reflects radiant heat, rather than absorbing it. The Consumer Guide to Energy Efficiency and Renewable Energy has more information on radiant barriers and how they work.
Radiant Heat: In “green” building, normally defined as heat radiating from a floor or wall and being transferred from a hot source within the wall or floor, usually circulated water. Radiant heat produces a more uniform heat within the room if properly installed. Zoning the heat is a method of concentrating heat only on areas that need it.
Radiant Heating: Radiant heating systems involve supplying heat directly to the floor or to panels in the wall or ceiling of a house. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating. Radiant heating has a number of advantages: it is more efficient than baseboard heating and usually more efficient than forced-air heating because no energy is lost through ducts. Hydronic (liquid-based) systems use little electricity, and can also be heated with a wide variety of energy sources, including standard gas- or oil-fired boilers, wood-fired boilers, solar water heaters, or some combination of these heat sources. For more information on radiant heating
Radon: A colorless naturally occurring, radioactive, inert gas formed by radioactive decay of radium atoms in soil or rocks that can be harmful to human health, including being a known carcinogen. Design strategies help reduce the amount of radon infiltration into a building and remove the gas that does infiltrate.
Rain Barrels: Rain barrels promote water conservation by collecting rainwater from roofs for use in irrigation. They are often used in association with native plants and Xeriscape™ landscaping. Rain barrels are available locally through the James River Basin Partnership.
Rainwater Catchment/Harvest: On-site rainwater harvest and storage systems used to offset potable water needs for a building and/or landscape. Systems can take a variety of forms, but usually consist of a surface for collecting precipitation (roof or other impervious surface) and a storage system. Depending on the end use, a variety of filtration and purification systems may also be employed.
Rain Garden: Low or depressed areas in a lawn where rainwater runoff is collected from impervious urban areas like roofs and driveways, reducing erosion and pollution of nearby streams. The water is then allowed to soak into the ground thus helping to recharge the underlying aquifer. Careful selection of water tolerant plants for the “garden” can result in an atteactive addition to a lawn that is also great for the environment.
Reclamation: Restoration of materials found in the waste stream to a beneficial use that may be other than the original use.
Recycled Content: The content in a material or product derived from recycled materials versus virgin materials. Recycled content can be materials from recycling programs ("post-consumer") or waste materials from the production process or an industrial/agricultural source ("pre-consumer" or "post-industrial").
Recycling: Process by which materials that would otherwise become solid waste are collected, separated or processed and returned to the economic mainstream to be reused in the form of raw materials or finished goods.
Recycling Areas: Space dedicated to recycling activities is essential to a successful recycling program, both on the construction site and in the building after occupation. For strategies related to determining recycling area configuration and placement, see the Business and Industry Resource Venture site.
Recycling Bins: Containers to temporarily hold recyclable materials until transferred to a larger holding facility of pick-up by a recycling service. Conveniently located bins increase recycling rates by allowing occupants to recycle more easily. Designing space for recycling bins is a physical reminder of a commitment to recycling.
Re-entry: (In indoor air program) Refers to air exhausted from a building that is immediately brought back into the system through the air intake and other openings.
Regional Manufacture: Goods produced within a certain radius of the project site. Using regionally produced goods is considered a sustainable building strategy in that it reduces the transportation impacts associated with the product, it often allows for a better understanding of the production process and increases the likelihood that the product was manufactured in accordance with environmental laws, and it supports regional economies.
Relative Humidity: Ratio of the amount of water vapor in air at a specific temperature to the maximum capacity of the air at that temperature.
Relite: Windows or translucent panels above doors or high in a partition wall intended to allow natural light to penetrate deeper into a building.
Renewable energy: Energy resources such as wind power or solar power that can keep producing indefinitely without being depleted.
Renewable Resources: A resource that can be replenished at a rate equal to or greater than its rate of depletion; e.g., solar, wind, geothermal and biomass resources.
Renovation: Upgrade of an existing building or space that maintains the original structure of a building.
Resource Conservation: Practices that protect, preserve or renew natural resources in a manner that will ensure their highest economic or social benefits.
Respirable: Particles or aerosols capable of being inhaled into the deep lung, less than 3 microns in diameter.
Reuse: Using a product or component of municipal solid waste in its original form more than once; e.g., refilling a glass bottle that has been returned or using a coffee can to hold nuts and bolts. 1 Reuse is a sustainable building strategy in that it reduces the strain on both renewable and nonrenewable resources, and when materials are reused on or near the site of salvage, they reduce transportation-related environmental impacts.
Risk Assessment: Qualitative and quantitative evaluation of the risk posed to human health and/or the environment by the actual or potential presence and/or use of specific pollutants.
Risk Factor Characteristics (e.g., race, sex, age, obesity) or variables (e.g., smoking, occupational exposure level) associated with increased probability of a toxic effect.
Roofing: There are a wide variety of green roofing materials from which to choose. The “greenest” roof is a living roof, planted with native drought-resistant plants, it’s both attractive and very energy efficient. There are also many more conventional roofing materials, which can help reduce energy usage, including reflective roofs, Structured Insulated Panels (SIPS) and both recycled and recyclable metal roofs, among others.
Route of Exposure: The avenue by which a chemical comes into contact with an organism, e.g., inhalation, ingestion, dermal contact, injection.
R-value: A measure of the thermal resistance and thermal transference of materials, especially insulation.
Salvage: Building materials diverted from the waste stream intended for reuse.
Sick Building Syndrome: A building whose occupants experience acute health and/or comfort effects that appear to be linked to time spent therein, but where no specific illness or cause can be identified. Complaints may be localized in a particular room or zone, or may spread throughout the building and may abate on leaving the building.
Siding & Other Exterior Finishes: Fiber-cement siding is highly durable; it doesn't split, holds paint longer and is more moisture-resistant than typical hardwood siding. Other green building siding options include recycled-content hardboard, natural or synthetic stucco and locally produced brick and natural or faux stone. Long lasting, low maintenance exterior finish products reduce replacement frequency, which means cost savings, reduced landfill impact, and fewer resources and time devoted to maintenance and replacement.
“Sink”: Gases and vapors often adsorb, and particles deposit, on surfaces such as carpet, drywall, etc. These surfaces are known as “sinks”—contaminants can be re-emitted from the sinks at a later time.
Smart house: Consists of programmable electronic controls and sensors that can regulate heating, cooling, ventilation, lighting, appliance and equipment operation in an energy conserving and climatically responsive manner.
Shower Facilities: In buildings that house workers, shower facilities are considered a green building feature in that they allow occupants that elect to travel by bicycle and other human powered modes of transportation to exercise this option.
Sisal: A durable natural fiber used as a floor covering, derived from leaves of the sisal plant.
Solar Collector: Any device used to capture or concentrate the sun’s energy. The leaves on a tree can be considered a solar collector, as can a window, solar panel, or dark surfaced thermal mass.
Solar Energy: A home can take advantage of solar energy in a number of ways. Passive solar design will save energy from the day you move in by taking advantage of the sun's "free" energy to help heat your home. Solar water heating is now less expensive than using electricity or gas to heat water. And solar panels can provide up to 40-60 percent of a home’s energy needs in the Ozark area. Net metering in Missouri and in Arkansas allows for reimbursement from utilities for excess energy and use of electricity from the grid when needed.
Solar Orientation: See Orientation (solar).
Solar Panels: General term for an assembly of photovoltaic modules. See photovoltaic. Use of solar panels is a sustainable building strategy in that it lessens a building’s reliance on nonrenewable sources of power distributed through the grid system.
Source Reduction: The design, manufacture, purchase or use of materials to reduce the amount or toxicity of waste in an effort to reduce pollution and conserve resources (i.e., reusing items, minimizing the use of products containing hazardous compounds, extending the useful life of a product and reducing unneeded packaging).
Practices that reduce the amount of any hazardous substance, pollutant or contaminant entering any waste stream or otherwise being released into the environment. Such practices also reduce the risk to public health and the environment associated with such releases. Term includes equipment or technology modifications, substitution of raw materials, and improvements in housekeeping, maintenance, training or inventory control.Stack Effect: Air, as in a chimney, that moves upward because it is warmer than the ambient atmosphere. The phenomenon in a building or building component caused by wind pressure and temperature differentials which results in air being drawn through some components of a building and out others creating a continuous pattern of air flow.
Staging: The sequencing and physical positioning of building materials on a construction site. Sustainable building pays particular attention to staging in order to minimize the impact to the construction site and protect materials from damage.
Straw-Bale Construction: Alternative building method using bales of straw for wall systems. The method uses an agricultural waste product in place of diminishing dimensional lumber, and achieves high insulation values. It is a building method most appropriate for regions with relatively little precipitation.
Structural Insulated Panel (SIP): Manufactured panels consisting of a sandwich of polystyrene between two layers of engineered wood paneling. Can be used for walls, roof, or flooring, and result in a structure very resistant to air infiltration.
Subsidies: Economic incentives to engage in an activity or purchase a product. Subsidies can work for or against environmental protection. Governments and utilities will sometimes offer subsidies for technologies that decrease energy or water use.
Sulfur Dioxide (SO2): A heavy, smelly gas that can be condensed into a clear liquid; used to make sulfuric acid, bleaching agents, preservatives and refrigerants; a major source of air pollution in industrial areas.
Sunshades: Devices for blocking unwanted solar gain.
Sustainability: Practices that would ensure the continued viability of a product or practice well into the future.
Sustainable Development: An approach to progress that meets the needs of the present without compromising the ability of future generations to meet their needs.
Sustainable Material: Materials that are generated from resources that are managed in a way that they are, for all practical purposes, sustainable over an extended period of time (i.e., the resource is not depleted).
Sustainable Development: An approach to progress that meets the needs of the present without compromising the ability of future generations to meet their needs.Superfund: The program operated under the legislative authority of CERCLA and SARA that funds and carries out EPA solid waste emergency and long-term removal and remedial activities. These activities include establishing the National Priorities List, investigating sites for inclusion on the list, determining their priority, and conducting and/or supervising cleanup and other remedial actions.
Teratogenesis: The introduction of nonhereditary birth defects in a developing fetus by exogenous factors such as physical or chemical agents acting in the womb to interfere with normal embryonic development.
Thermal Break: Method of increasing the thermal performance of a material or assembly by reducing conductive heat loss. By inserting a less thermally conductive material in a material or assembly that bridges conditioned and unconditioned space, the conductive path is reduced or broken. An example is the thermal break featured in aluminum-framed windows.
Thermal Bridging: Unwanted heat loss or gain due to conduction through a material. An example of thermal bridging is heat loss that occurs with structural steel framing that is insufficiently insulated between conditioned and unconditioned space. A thermal bridge is a highly conductive element such as a metal channel in the building envelope that penetrates or bypasses the less conductive element such as insulation, and acts as a thermal short circuit through the insulation system.
Thermal buffer: A space or other element that reduces the heating and cooling load on another space located between the space and the exterior.
Thermal envelope: The shell of a building that essentially creates a barrier from the elements. A highly insulated thermal envelope allows maximum control of interior temperatures without outdoor influence.
Thermal by-pass: An opening between a conditioned and unconditioned space that heated or cooled air can move through, therefore violating the air tightness of the building envelope.
Thermal flywheel: A space or other element such as a solid masonry wall that collects heat during one period and releases it during another in a repetitive pattern.
Thermal Mass: A mass (often stone, concrete, or brick) used to store heat and reduce temperature fluctuation in a space, by releasing heat slowly over time.
Thermal Pollution: The addition of heat to a body of water that may change the ecological balance.
Thermostats: The average household spends more than $2,000 a year on energy bills — nearly half of which goes to heating and cooling. Programmable thermostats can help homeowners save about $180 a year by establishing a program that automatically reduces heating and cooling in their home when they don’t need as much. For a rebate from City Utilities
Therms: Unit of measure for natural gas and a heating value equivalent to 100,000 British Thermal Units (a BTU is the amount of heat needed to raise the temperature of 1 pound of water 1 degree Fahrenheit).
Tipping Fee: Charge for the unloading or dumping of waste at a recycling facility, composting facility, landfill, transfer station or waste-to-energy facility.
Toilets: Old, inefficient toilets are responsible for most of the water wasted in homes. Replacing these toilets with high-efficiency models (HETs) including waterless composting, low water and dual flush toilets, could save many gallons of water per day. Still more water can be saved by using gray water to flush toilets. For a rebate from City Utilities
Total Volatile Organic Compounds: The total mass, typically in milligrams per cubic meter, of the organic compounds collected in air.
Toxic: Capable of having an adverse effect on an organism; poisonous; harmful or deadly.
Toxic Release Inventory: Database of toxic releases in the United States compiled from SARA Title III Section 313 reports.
Transpiration: The process by which water vapor is lost to the atmosphere from living plants. The term can also be applied to the quantity of water thus dissipated.
Trombe Wall: Thermal storage system used in passive solar design. A high-mass wall that stores heat from solar gain during the day and slowly radiates the heat back into the living space at night.
Truck Tire Wash Down Area: A strategy for removing dirt and other contaminants from construction vehicles in order to prevent stormwater contamination related to transport of contaminants offsite on vehicle tires. A specified area is created for wash down, with structural controls in place to prevent wash down waters from entering the storm system or the larger environment.
Urea-Formaldehyde Foam Insulation: A material once used to conserve energy by sealing crawl spaces, attics, etc.; no longer used because emissions were found to be a health hazard.
U (U-Value): A measure of the amount of heat that flows in or out of a substance under constant conditions when there is a one degree difference between the air within and outside a building. U-values are used in determining the performance of a glazing system or window assembly.
VAV Systems: Variable Air Volume Systems operate by opening and closing the air flow in certain areas of a building as the load shifts during the day depending on the sun and the weather.
VFD's: Variable Frequency Drives run the motors for various equipment at reduced speeds, thereby reducing electrical motor consumption while still satisfying the needs of the building.
Ventilation: As homes have become increasingly airtight, concern over indoor air quality has increased. Moisture from cooking and washing can increase the occurrence of mold, mildew, fungi, dust mites and bacteria inside the home. Carbon monoxide and other pollutants may accumulate from various appliances, heaters, and chimneys, and paints, lacquers, finishes, and new building products can add other pollutants to the indoor air.
Air exchange, particularly the use of natural cross ventilation to increase air flow, is an important part of green building design. When heating a building, heat recovery ventilators can help reduce the cost of heating fresh incoming air.Ventilation Control (by Occupants): The ability of building occupants to control ventilation rates. A strategy for giving control of comfort back to occupants, this can be achieved through access to individual electronic controls or by operable windows in workspaces. Studies show that giving increased control to occupants over their environment results in greater occupant tolerance for variability in the indoor environment.
Ventilation Rate: The rate at which indoor air enters and leaves a building. Expressed as the number of changes of outdoor air per unit of time: air changes per hour (ACH), or the rate at which a volume of outdoor air enters in cubic feet per minute (CFM).
Volatile Organic Compounds (VOC): Organic substances capable of entering the gas phase from either a liquid or solid form. Organic chemical compounds that have high enough vapor pressures that, under normal conditions, allow them to significantly vaporize and enter the atmosphere, potentially inflicting damage on the environment or causing harm to health. VOCs are chemicals that contain carbon molecules and are volatile enough to evaporate from material surfaces into indoor air at normal room temperatures (referred to as off-gassing). Examples of building materials that may contain VOCs include, but are not limited to: solvents, paints, adhesives, carpeting and particleboard. Signs or symptoms of VOC exposure may include eye and upper respiratory irritation, nasal congestion, headache and dizziness. Least toxic" products are those that contain levels of VOCs below what the EPA or other credible sources have determined to be safe levels. In some cases, a "least toxic" product may be preferable to a "non-toxic" product for performance reasons.For more information
Walk-off Mat: Design strategy for reducing the amount of contaminants introduced into an interior space by providing grating or other material to remove contaminants from shoes. A significant portion of contaminants in a building are brought in this way, impacting indoor environmental quality.
Wastewater: The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter.
Waste Management Plan: See Construction Waste Management
Water Heaters: Water heating can account for 14%–25% of the energy consumed in your home. You can reduce your monthly water heating bills by selecting the appropriate water heater for your home or pool and by using some energy-efficient water heating strategies. Luckily, there are a growing number of options for water heating systems with improved energy efficiency, including solar water heaters, tankless water heaters, and heat pump water heaters.
Watersense: Toilets are by far the main source of water use in the home, accounting for nearly 30 percent of residential indoor water consumption. Toilets also happen to be a major source of wasted water due to leaks and/or inefficiency. WaterSense is a program sponsored by the U.S. Environmental Protection Agency (EPA). The WaterSense label is used on toilets that are certified by independent laboratory testing to meet rigorous criteria for both performance and efficiency.
Water-Source Heat Pump: Heat pump that uses wells or heat exchangers to transfer heat from water to the inside of a building. Most such units use ground water. (See groundsource heat pump; heat pump.)
Waterless Urinal: Urinal with no water line. Most designs use a specialized material that allows fluid to drain one-way into the sewer system.
Watts per Square Foot: A shorthand measure of the energy use of a building, often applied to indoor lighting. Energy codes often limit the watts per square foot based on building type and function.
Wetlands: An area that is saturated by surface or ground water with vegetation adapted for life under those soil conditions, as swamps, bogs, fens, marshes, and estuaries.
Windows: The largest heat loss in a building can be found through the windows. But perhaps more than any other building component, windows have seen a significant increase in performance using new technologies, including double and triple-panes, Low E coatings and gas-filled windows, which improve the insulation value. While high performance windows may cost slightly more, the energy savings often result in a rapid pay back. For more information
Wind Turbine: A device for generating electricity from wind and often storing the energy in a battery storage system for later use, or the power is passed back to the utility essentially making the meter go in reverse.
Window Shading: Any device for reducing unwanted heat gain from a window.
Worm Bin: System for on-site management of food scraps and other organic materials. Similar to a compost bin, a worm bin uses worms to digest organic wastes, in a process known as "vermicomposting".
Xeriscape™: Simply put, Xeriscape means the use of native, drought-tolerant plantings that can survive in our climate without lots of watering and using irrigation techniques that conserve the water you do supply. In general, Xeriscape™ should be the landscape option of choice and is often combined with rain-harvesting barrels, cisterns and/or grey water systems to maximize the conservation of a limited and essential resource—water.