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Acid Rain:   Atmospheric precipitation formed by the mixture of industrial pollutants – such as sulfur dioxide and nitrogen oxides – with naturally occurring oxygen and water vapor.  Acid rain has adverse effects on forests, freshwater, insect and aquatic life-forms and causes damage to buildings and human health.

Active Solar: The use of electrical or mechanical equipment – such as pumps and/or fans – to collect, store and/or convert solar energy into electricity for heating and/or cooling.

Adaptability: A sustainable building design strategy that allows easy evolution and changes in a space for multiple future uses.  This building strategy reduces the extent to which major renovation must be performed.

Adaptive Reuse: To renovate a building by using original elements of the original site for a different purpose for the initial space.

Agricultural Waste: Leftover materials – such as wheat stalks, shell hulls, etc. – from agricultural processes that are incorporated into new building materials and finishes.  For example, wheat stalks are used in structural sheathing and seed hulls are used to make panels.

Algae Biofuels: A third generation biofuel that is sustainably derived from algae – instead of corn, sugar canes, or grasses.  Algae have a quick growth rate and unlike previous generations, will not destroy farmlands or interrupt food supplies.

Algal Bloom: A dramatic increase in algae populations often due to excess nitrogen and phosphorous in rivers and streams.  Algal blooms can kill aquatic life if they are too severe, absorbing all accessible oxygen.

Alternative Energy: any energy that is renewable as compared to traditional carbon based fossil fuels. These include sources of energy such as solar energy, wind power, and wave power.

Alternative Fuels: These fuels are produced from resources other than petroleum. These fuels are derived from renewable sources of energy such as electricity, ethanol, hydrogen, and biodiesel. The use of these fuels reduces our dependence on imported oil, and produces less pollution than gasoline or diesel.

Alternative Fuel Vehicles: Low-polluting vehicles powered by non-gasoline fuels – such as electricity, hydrogen, propane or compressed natural gas, liquid natural gas, methanol, and ethanol. Gas-electric hybrid vehicles are also included in this group.

Alternative Refueling Station: Location that provides alternative fuel vehicles access to their necessary fuel – such as electricity, compressed natural gas, etc. This is a sustainable building strategy because it encourages the use of alternative fuels and the vehicles that use them.



Biodegradable: This term refers to materials that are broken down naturally and can be reabsorbed into the eco-system.  Landfills can often slow down or prevent biodegrading; composting materials provides the ideal conditions for biodegradation

Biodiesel: This is a non-petroleum based diesel fuel derived from vegetable or animal fats. Ethanol is the most common form of biodiesel, based on corn, sugar cane or other organic matter such as algae or switchgrass.

Biomass: Organic matter – such as wood, agricultural waste, etc. – that serves as a source of energy.

Blackwater: Wastewater that is generated by toilets. Blackwater can be neutralized and later used for non-potable uses – such as flushing or irrigation.

Building Envelope: This includes all elements – such as walls, windows, insulation, siding, etc. – that enclose a building serving as a thermal barrier between the indoor and outdoor environment. A well-designed building envelope minimizes energy consumption for cooling and heating while promoting the influx of natural light.

Building Footprint:  This is the outline of the area on a project site that is surrounded by the building structure – such as exterior walls.




Cap-and-Trade System: This is a market-based approach to controlling pollution that allows organizations to trade emissions allowances that have a cap, or limitation, on the emissions. 

Carbon Dioxide: (CO2) is a naturally occurring greenhouse gas in the atmosphere. CO2 is also created when we burn fossil fuels, leading to global warming. CO2 is a primary greenhouse gas that is linked to global warming and climate change. 

Carbon Footprint: This footprint  is the measure of environmental impact resulting from the actions (lifestyle or operation) of an entity (from individual to company to governmental unit) measured in units of carbon dioxide.

Carbon Monoxide: This gas is a colorless, odorless and highly toxic gas commonly created during combustion.

Carbon Neutral: This term refers to an action that does not result in an overall increase in carbon emissions. It is also possible that carbon emitters can off-set their emission to be carbon neutral.

Carbon Offset: This is a credit that can be purchased to negate carbon emission activities. Revenue generated from the purchase of offsets is typically invested in environmental projects that mitigate the impact of carbon emissions. When purchasing carbon offsets be sure to verify the effectiveness and credibility of the organization selling them.

Carbon Rationing: A method to limit the amount of carbon used each year. Carbon rationing helps you reduce your carbon footprint.  By pro-actively using carbon rationing tools, such as smart meters or energy efficient appliances, or making carbon reduction choices, such as carpooling or offsetting flights, you will be able to lower your carbon footprint.

Carbon Sink: This occurs when carbon is absorbed by natural systems such as oceans, forests and peat bogs.

Carbon Tax: This is a charge on fossil fuels based on their carbon content.

Carbothermic Reactions:  these are thermic chemical reactions which use carbon as the reducing agent at high temperature.  This process functions to generate metal when the oxide to be reduced is a weaker reducer than carbon.  For instance, sodium and potassium cannot be reduced from their oxides in this fashion but iron can be reduced from carbon.

Carbothermal Reduction:  A type of reduction that involves carbon as the reductant at elevated temperatures, often above 800°C.


Carpool: An arrangement where two or more people share a vehicle for mutual transportation.

Chlorofluorocarbons: (CFCs) are man-made chemical compounds containing carbon, chlorine, fluorine and sometimes hydrogen. The chlorine in CFCs damages the ozone layer.

Clean Computing: A chain that includes the manufacture, use and disposal of IT equipment without producing any harmful waste at any stage. Non-hazardous materials are used in chip construction and packaging.

Climate Change: A global change in temperature and weather patterns due to human activity.

Cogeneration: A process in which a gas-fired engine and a generator set produce power.  The heat produced is used for heating and/or cooling media. Cogeneration plants are often referred to as a combined heat and power plant.

Compact Fluorescent Lamp (CFL): Fluorescent lamps – that has been compressed into a standard size – used as more efficient alternatives to incandescent lighting. CFL’s last at least six times longer than incandescent bulbs while using a quarter of the power.

Composting: Organic wastes are decomposed naturally in this controlled process to produce a product rich in minerals, often used as a soil conditioner.  This controlled process can be used in the presence of air by mechanical mixing and aerating, ventilating materials through chambers, or periodically mixing in an open air environment.

Conservation: Preserving and renewing, when possible, natural and human resources.
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.

Cradle-to-Cradle: A term used in life-cycle analysis and reporting to describe a material or product that is recycled into a new product at the end of its defined life.

Cradle-to-Grave: A term used in life-cycle analysis and reporting 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.




Daylighting: The use of natural light to supplement or replace artificial lighting. By utilizing solar light, daylighting creates a stimulating and productive environment for building occupants. 

Displacement Ventilation: A method by which conditioned air is supplied at or near the floor at very low velocities. This allows a cool layer of air to collect in occupied zones, creating comfortable conditions for the occupants. The buoyant forces remove occupant and equipment generated heat, while removing odors and pollutants through the exhaust fans. This ventilation system provides energy savings and improved indoor air quality.



E-cycling: E-cycling is reusing electronic equipment and components, rather than discarding them.  Many non-functioning devices can be refurbished, resold or donated.  

Eco-assessment: This is an evaluation of any building, whether a home or workplace to define ways to reduce the impact on the environment. Areas of emphasis include energy analysis, recycling, and water usage.

Eco-bus: This is a bus which uses a combination of diesel and electric power.

Eco-friendly: This term means there is little or no impact on the native eco-system by a product or method.

Ecological Footprint: The area of land and water needed to produce the resources to entirely sustain a human population and absorb its waste products with prevailing technology. The concept of an ecological footprint is used as a resource management and community-planning tool.

Economizer: These devices are used in data centers to reduce energy consumption.  These devices replace or complement cooling devices in the data center by utilizing the cooler outside temperatures to cool the IT equipment inside the facility.  These devices can reduce energy consumption costs by more than 60%, in cooler climates.

Electronic Waste or E-waste:  Electronics that are no longer being used because they are broken, obsolete, or discarded.

Embodied Energy: This is the total energy used to create a product, including the energy used in mining or harvesting, processing, fabricating, and transporting the product.

Emissions Cap: This is a limit placed on large scale use regarding the amount of greenhouse gases that can be emitted.

Energy Efficiency: This term refers to the technology and actions that reduce the amount of electricity or fuel used.

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 Saving Grant: This is money awarded to you to help improve the efficiency of your home and use less energy.

Energy Saving Light Bulbs: These light bulbs use far less energy than conventional bulbs.

Energy Star: Program administered by the Environmental Protection Agency that evaluates products based on energy efficiency. ENERGY STAR Rating is the rating a building earns using the ENERGY STAR Portfolio Manager to compare building energy performance to similar buildings in similar climates. A score of 50 represents average building performance.




Fossil Fuel: These fuels include coal, oil and natural gas which are fuels created by decomposition of carbon based fossilized plants and animals.

Fuel Cell: This is 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.



Geo-engineering: Geo-engineering is the intentional modification of a planet's environment by the addition or subtraction of a resource or energy input on a massive scale. Proposed geo-engineering projects have included space mirrors, sulfur-spraying in the stratosphere, cloud seeding and oceanic carbon sequestration.

Geothermal Energy: This is heat based energy that is tapped from the earth.

Geothermal Heat Pump: In order to collect geothermal energy, a geothermal heat pump is used. This uses water and antifreeze in pipes to move the heat from the earth to homes in winter.  During the summer, this pump can remove heat from the house and store it underground.

Global Warming: This phenomenon is an increase in the average temperature of the earth, attributed to the burning of fossil fuels.

Green: This adjective is used to describe people, behaviors, products, policies, standards, processes, places, movements or ideas that promote, protect, restore or minimize damage to the environment.

Green Building: This edifice uses eco-friendly building materials in construction; a building that minimizes impact on the environment through resource (energy, water, etc.) conservation and contributes to the health of its occupants. Comfortable, aesthetically pleasing and healthful environments characterize green buildings

Green Computing: This includes all environmentally responsible methods to use a computer.  Green Computing can include implanting energy-efficient central processing units (CPUs), servers and other devices to reduce consumption.  Green computing can also include green software that will monitor the amount of energy different programs and processes use.

Green Data Center:  A data center can be transformed into a green data center by designing the mechanical, lighting, electrical and computer systems to become energy efficient.  These advanced strategies will minimize the carbon footprint of the data center.

Green Design: A design that conforms to environmentally sound principles of building, material and energy use.  A design, usually architectural, conforms to environmentally sound principles of building, material and energy use. A green building, for example, might use solar panels, skylights and recycled building materials.

Green Development: A sustainable approach to real estate development that emphasizes environmental issues such as: appropriate use of land, energy, water, and other resources; protection of significant habitats, endangered species, etc; and integration of work, habitat and agriculture.

Green Networking: This is the use of telecommuting and videoconferencing in order to consolidate devices.  These forms of virtualization reduce power consumption on a network.

Green Roof: A building roof is used as a contained green space. This roof maintains living plants and a drainage system.  As a part of the sustainable building strategy, the green roof tries to offset the temperatures in and around the building while reducing storm water runoff.

Green Technology: This is the application of innovative and energy efficient tools, materials and design to conserve and protect the environment; this includes everything from renewable energy and water sanitation to recycling and home appliance advances.

Greenhouse Effect: This effect is the basis of global warming. Gases—such as carbon dioxide, chlorofluorocarbons, and ozone—are trapped in the atmosphere and capture the sun’s energy; this process raises the temperature of the air and the earth, causing global warming.

Greenhouse Gases: Any gas that absorbs infrared radiation in the earth’s atmosphere. Common greenhouse gases include water vapor, carbon dioxide (CO2), methane (CH4), nitrogen oxides (NOx), ozone (O3), chlorofluorocarbons (CFCs), halogenated fluorocarbons (HCFCs), perfluorinated carbons (PFCs), hydrofluoro-carbons (HFCs) and Sulfur Hexafluoride (SF6). Carbon dioxide, methane and nitrogen oxides are of particular concern due to their long residence time in the atmosphere.

Green Power: Electricity generated from renewable energy sources (solar, wind, biomass, geothermal, and hydroelectric).

Greywater: This is household waste water that does not contain sewage or fecal contamination (such as from the shower) and can be reused for irrigation after filtration.

Grid: This is a network of power transmission and distribution facilities used to provide electricity to users (homes, businesses, industry).




Heat Island Effect: A phenomenon that occurs in developed areas where the replacement of natural land cover with paving, buildings, roads, parking lots, etc. result in an increase in outdoor temperatures.  

High Efficiency: General term for technologies and processes that require less energy, water, or other inputs to operate.

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.

Hybrid Vehicles: Vehicles that use a gasoline engine to drive an electric generator and use the electric generator and/or storage batteries to power electric motors that drive the vehicle’s wheels.

Hydroelectric Energy: This is electric energy produced by water falling from a high elevation to a lower elevation turns generators.  This renewable energy source derives its energy from rain and gravity. 

Hydrofluorocarbons: used as solvents and cleaners in the semiconductor industry, among others; experts say that they possess global warming potentials that are thousands of times greater than CO2.




Insolation: The amount of sunlight (direct, diffuse and reflected) reaching an area exposed to the sky. 

Integrated Design: This is a holistic process that considers different components of a building and examines the design, construction, and operations to optimize the energy and environmental performance of the project.

Integrated Waste Management: This is the complementary use of a variety of practices to handle solid waste safely and effectively; such as reduction, recycling, composting, combustion and land-filling.

Integration: By viewing a building as a system, the design is able to discovery an approach to help maximize synergies and minimize unintended consequences.

Intelligent Materials:  Materials that are able to adapt to their environment by altering their properties.





Kilowatt-hours (kWH): This measurement is used to gauge electricity and natural gas usage.




Landfill: This is an area where waste is dumped and is covered with dirt and topsoil. Following federal law, solid waste landfills are located away from eco-sensitive environments to prevent contaminants in the soil, air and water.  The hazardous waste and gas emissions can be converted into an alternative energy source. 

LEED:  LEED is a point-based rating system developed by the US Green Building Council that evaluates the environmental performance from a “whole building” perspective over its life cycle, providing a definitive standard for what constitutes a green building.

Levelised Cost Of Energy:  LCOE is the cost of generating energy (usually electricity) for a particular system.  As an assessment of generation costs it includes all the costs over the system’s life such as the initial investment, operations and maintenance, fuel cost, and the capital cost.  This allows determination of the minimum price that generated energy must be sold to achieve break even.

Life Cycle Assessment: This assessment is a methodology developed to assess a product’s full environmental costs, from raw material to final disposal.

Life-cycle Cost (LCC): The total cost of acquiring, owning, operating and disposing of a building or building system over its entire useful life. LCC includes the cost of land acquisition, construction costs, energy costs, the cost to maintain, service and repair the building and its systems, costs of system replacement, financing costs, and residual or salvage value at the end of the building’s useful life.

Light-emitting Diode (LED) is a semi-conductor light source valuable as a long-lasting illumination technology.  When a diode is forward biased (switched on), electrons are able to recombine with holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light, corresponding to the energy of the photon, is determined by the energy gap of the semiconductor.

These energy-efficient lights consume 80 percent less energy than conventional, incandescent bulbs. Common in digital clocks, remote controls, watches and appliances, they are now being produced in bulb form as a home lighting alternative.


Low-e Glass: Low-e (Low emissivity) glass has an invisible thin-film metallic or oxide coating which allows the passage of short-wave solar energy into a building but prevents long-wave energy produced by heating systems and lighting from escaping outside.

Low-emission Vehicles: These vehicles have engines that emit less pollution compared to conventional engines.




Microclimate: Localized climate conditions within an urban area or building. 




Natural: Purely defined, natural means anything found in nature or derived directly from plants, animals or minerals. Natural products do not contain any man-made (synthetic) ingredients.  

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 beams to direct airflow on a site, and operable skylights.

Net Metering: A metering and billing arrangement that allows on-site generators to send excess electricity flows to the regional power grid. These electricity flows offset a portion of the electricity flows drawn from the grid.

Non-Renewable:  Resources such as oil, coal, and natural gas only exist in limited supply. Energy resources that cannot be restored or replenished by natural processes and therefore are depleted through use. Commonly used non-renewable energy resources include coal, oil, natural gas, and uranium.




Offsetting:  The process of reducing carbon emissions by a carbon emitting activity that compensates another entity, resulting in reducing its carbon use equal to its carbon emission.   

Organic: This term is used for anything that is natural and without additives or man-made embellishment. Organic refers to agricultural methods designed to sustain soil life and biodiversity while forbidding the use of pesticides and fertilizers, genetically modified organisms, irradiation, sewage sludge, antibiotics and hormones (in livestock) and other practices.

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.

Ozone Layer: The protective layer in the atmosphere, about 12-15 miles above sea level, which absorbs some of the sun’s ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches the earth's surface.




Passive Solar: The use of natural heat transfer processes to collect, distributes, and store useable heat without the help of mechanical devices (pumps or fans). Passive solar systems have few moving parts.  

Photovoltaic (PV): PV is a technology that converts sunlight into electricity. Power is produced when sunlight strikes the semiconductor material and creates an electrical current. At this time, solar photovoltaic panels are the common application of this technology.

Photovoltaic Cell: This is a device that converts sunlight directly into electricity. Photovoltaic (PV) cells are silicon-based semiconductors and are often referred to as solar cells

Photovoltaic (PV) Module: This module is an integrated assembly of interconnected photovoltaic cells.  It is designed to deliver a selected level of working voltage and current at its output terminals and is designed to be incorporated in photovoltaic power systems.

Pollution: Pollution is caused by the presence of a substance in the environment that prevents the functioning of natural processes and produces undesirable environmental and health effects.

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.

Power Management: This feature is included in many electrical appliances, such as copiers and computer equipment, which turns off the power or switches to a standby mode when inactive. Power management features can save individuals and organizations substantial energy costs over time.

Plastic: This is a petroleum-based man-made synthetic-based product that is flexible and durable.

Plastic Bags: These are not good for the environment because plastic is not biodegradable.

Public Transportation: Mass transit, including bus and light rail systems, as opposed to single occupancy vehicles reduce emissions to the environment.






Rainwater Harvesting: By collection, storage, and reuse of rainwater, the water can be used to offset potable water needs for a building and/or landscape.  These systems can include precipitation collection and storage systems along with a variety of filtration and purification systems.  

Recycling:  This is the process of collecting, sorting, and reprocessing old material into usable raw materials. Commonly recycled items include cans and bottles, paper and industrial solvents. Recycling can also apply to construction materials, and even to buildings themselves.

Refurbished: Products are upgraded to be returned to active use in their original form. Refurbishing is considered a form of reuse, and is preferable to recycling as it requires less processing and inputs to return a product to useful service.

Regeneration: Renewal of sites or habitats that have become unfit for human, animal, or plant habitation, bringing them back into productive use. The term most commonly refers to urban and industrial land.

Renewable Energy: This includes alternative energy sources such as wind power or solar energy that can keep producing energy indefinitely without exhaustion.

Renewable Resources: Like renewable energy, resources such as wind, sunlight and trees that regenerate.

Renovation: Upgrade of an existing building or space that maintains the original structure of a building.

Retrofit: The replacement, upgrade, or improvement of a piece of equipment or structure in an existing building or facility.




Solar: Passive vs. Active. Active solar technology uses electrical or mechanical equipment to convert the sun's rays into usable energy. Passive solar technology does not use any outside non-solar energy.

Solar Collector: A device used to absorb heat from the sun. In the context of buildings, the absorbed energy typically heats water, which is then used for space heating and/or domestic hot water.

Solar Heating: This form of heat comes from the sun that is absorbed by collectors and transferred by pumps or fans to a storage unit for later use or to the house interior directly.

Solar Panels: The general term for the assembly of photovoltaic modules. Solar panels are used in a sustainable building strategy because it lessens a building’s reliance on nonrenewable sources of power distributed through the grid system.

Standby Power: This is the electrical power consumed by a device when it is not in use but is plugged into a source of power, ready to be used.  The power drainage is so small that it is not apparent.  Appliances that use standby power are televisions, computers, computer equipment and other devices that may also use battery chargers.

Sulfur Dioxide (SO2): SO2 is a heavy, smelly gas which can be condensed into a clear liquid. Used to make sulfuric acid, bleaching agents, preservatives and refrigerants, it a major source of air pollution.

Sustainability: This focuses on the long term ability to maintain and preserve systems whether the environment or manmade systems. At the heart of sustainability is the concern to support long term value for future needs. Key initiatives include sustainable architecture, sustainable agriculture, and sustainable urban development

Super-Insulation: Insulating a building to minimize the amount of heat that can escape from (or, in a hot climate, enter) a building.




Telecommuting: This is the use of telecommunication to work outside the traditional office or workplace, usually at home or in a mobile situation. Telecommuting can reduce greenhouse gases, save gasoline usage and associated purchase costs and reduce urban traffic congestion. 

Thermal Break: Method of increasing the thermal performance of a material or assembly by reducing conductive heat loss. 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.

Thermal Mass: A material used to store heat, thereby slowing the temperature variation within a space. Typical thermal mass materials include concrete, brick, masonry, tile and mortar, water and rock.

Toxic: Capable of having an adverse effect on an organism; poisonous; harmful or deadly.






Value Engineering: An organized activity where  building systems, equipment, design features and materials are analyzed to attain the lowest building life cycle cost while maintaining the stated functional and performance goals including quality, reliability, and safety.

Volatile Organic Compounds (VOC): Organic compounds that evaporate at room temperatures and are often hazardous to human health, causing poor indoor air quality. Sources of VOC’s include solvents and paints.




Wastewater: The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter.  

WEEE: This acronym stands for Waste Electrical and Electronic Equipment, and encompasses electronic equipment such as computers, mobile phones, monitors, etc. 

Wind Power: This is energy generated from the wind. These systems convert air movement into mechanical or electrical energy. Driven by the wind, turbine blades turn a generator or power a mechanical pump.

Wind Turbine: A device that converts the kinetic energy of the wind into mechanical energy that can be used to drive equipment such as pumps. The addition of a generator allows the wind’s kinetic energy to be converted into electricity. There are two types of wind turbines, namely: horizontal axis turbines - blades rotate about a horizontal axis; and vertical axis turbines - blades rotate about a vertical axis.



Xeriscaping: Landscaping design for conserving water that uses drought-resistant or drought-tolerant plants.





Zero or Low-Energy Building: This edifice has no net energy consumption when measured across a year's time. It uses alternative energy sources like solar and wind power.