Green explained...

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A is for...

Acetate: Generic term for man-made fibers composed of cellulose acetate, a substance derived from cellulose by action of acetic anhydride and other chemicals. Commonly used in adhesives.

Acid Rain: Precipitation that has a pH below 5.6. Main contributors are sulfur dioxide from industrial burning of fossil fuel, and nitrogen oxide from automobile emissions, which is transformed into nitrogen dioxide. Rainfall increases the pH of the surfaces on which it falls, which can cause physical damage or contamination. 

Acrylic Polymers: A family of plastic materials used for rigid plastic sheets (Plexiglas), liquid coatings (floor and wax sealers), paints, and several other products. Acrylics are made from acrylic acids, methacrylate, or acrylonitrile, all derived from petroleum. Acrylonitrile is a known carcinogen. Acrylic plastics are relatively stable and low in toxicity. 

Adhesive: Material that bonds surfaces of different materials. Adhesives may be liquid or tacky semi-solids, natural or synthetic, organic or inorganic, waterborne, solvent-borne, or solvent-less. VOC's are typically the source of ecological harm with most adhesives. 

Agricultural By-product: Ancillary product of farming, several of which may be used in building materials (strawboard or agriboard).

Air Economizer: A ducting arrangement and automatic control system that allows a cooling supply fan system to supply outside air to reduce or eliminate the need for mechanical refrigeration during mild to cold weather.

Air Infiltration Barrier: Consists of one or more air-impermeable parts and is used to seal building walls. Air Infiltration Barriers dramatically reduce air flow through a building's envelope reducing the loss of conditioned air (improved efficiency)

Alergen: A chemical or biological antigenic agent that causes allergic reactions in susceptible individuals. Reactions can vary: skin rashes, breathing difficulty, fever, etc.

Arsenic: A Poisonous metal. Soft element with a metallic luster. Obtained as a by-product from smelting metals (copper, lead, cobalt, and gold). Commonly used as s wood perservative, herbicide, pesticide, and specialized glass. Identified by the EPA as a persistent, bioaccumulative, toxic pollutant.

Arsenical: Biocide containing arsenic. Commonly used to protect wood products from insect damage.

B is for...

Batt Insulation: Glass or mineral woool, which may be faced with paper, aluminum or other vapor retarders. Commonly used for thermal or sound insulation in walls and ceiling cavities.

Biocide: Toxic chemical additive capable of killing or inactivating micro-organisms. Used in anti-foulants, preservatives, paint, polymer and rubbers.

Biodegradable: Capable of decomposing into elements naturally found in nature. 

Biodiversity: The range or variety of species which comprise a given ecosystem. 

Black water: Also, blackwater. Waste water from toilets and other effluent streams; typically not included (though possible) in water recycling initiatives such as greywater systems. 

Brownfield: Abandoned, idled, or underused industrial and commercial facilities and sites where expansion or redevelopment is complicated by real or perceived environmental contamination. Environments which can be improved with design. 

Building Envelope: The elements that enclose a building's conditioned spaces. The main line of defense against thermal transfers between conditioned and unconditioned spaces.

Building Integrated Photovoltaics (BIPV): Building envelopes which function both as an enclosure system and system which harvests solar energy.

C is for...

Carbon Footprint: The sum total of greenhouse gasses that are produced to support human life and activities; often measured for individuals. Measurements typically appear in tons of carbon dioxide, and directly correlate to global warming. 

Carbon Monoxide: Poisonous, colorless, odorless gas formed by incomplete fossil fuel combustion. Combines with hemoglobin in blood and prevents oxygen from being released to body tissues.

Carbon Neutral: 1. Anything that inherently does not emit carbon emissions. 2. The result of offsetting carbon emissions. A simple example is planting vegetation which absorbs carbon emissions to offset generated emissions. 3. The result of purchasing carbon credits to offset emissions, see Carbon Trading. 

Carcinogen: Cancer-causing agent. May be physical (radiation, asbestos fibers), viral or chemical.

Carnauba: Hard natural wax sourced from Carnauba palm leaves. Low toxicity. Used in waxes and varnishes when a hard, high-polish is required. Also known as Brazil wax.

Cellulose Insulation: Thermal insualtion made from recycled newspaper. Often treated with borates to provide protection from fire and rodents. These additives can cause health issues for sensititve individuals.

Chemically Stable: Any material that will not readily break down, release chemicals, or change into other chemicals with age, heat or light.

CFC: Officially called Chlorofluorocarbon, CFC is a group of volatile, non-reactive, non-corrosive, non-flammable and easily liquefied gases. CFC gases are believed to be responsible for the stratospheric ozone, therefore; the EPA has banned their use (effective since 1997).

CITES: Convention on International Trade in Endangered Species of Wild Fauna and Flora. Provides lists of endangered species of timber and other natural products.

Class I Substance: One of several groups of chemicals with an ozone depletion potential (ODP) of 0.2 or higher, including CFCs, halons, carbon tetrachloride and methyl chloroform, and HCFCs and ethyl bromide, as defined by EPS and the Clean Air Act.

Class II Substance: A substance with an ozone depletion potential of less than 0.2. All HCFCs are currently included in this classification.

Clear Cutting: The process of harvesting every tree in an area; can result in accelerated runoff, erosion, sedimentation of streams and lakes, flooding, and destruction of vital habitat.

Collector Efficiency: Collector efficiency is a measure of the percentage of available solar energy that the collector will transmit to the heat transport fluid.

Clear Cutting: Controlled biological decomposition of organic refuse in which such materials are mechanically mixed, ground, or shredded, then decomposed to humus in windrow piles, or in aerated enclosures such as mechanical digesters or drums.

Conditioned Air: Air treated to control its temperature, relative humidity, purity, pressure, movement, or other characteristics to obtain a desired environment.

Conductivity (k): The quantity of heat that wil pass through a material over a period of one hour given a surface temperature difference of 1 degree Farenheit.

Constructed Wetland: Engineered wetlands that simulate natural wetlands. Natural and biological processes are used for wastewater treatment. Includes surface and subsurface flow constructed wetlands. Subsurface flow wetlands are further divided into horizontal flow and vertical wetland treatment systems.

Contaminant: Foreign and unwanted physical, chemical, biological, or radiological material in a product or in the environment.

D is for...

Daylighting Strategies: Methods that use natural light to minimize the need for artificial lighting during the day. For example, a clerestory allow natural light into the building interior through a raised section of roof with vertical glass; shading the glass allows light in while reducing heat gain.

Dead Air Space: A confined space of air with no airflow. Dead air space tends to reduce both conduction and convection of heat. This attribute is utilized in virtually all insulating materials and systems, such as double-glazed windows, fiberglass batt insulation, rigid foam panels, and loose-fill insulations such as pumice, vermiculite, rock wool, and goose down.

Downcycling: A recycling process through which waste material is turned into useful material of significant lower quality or function.

Downstream Impact: Impact to the environment from an upstream activity. In the case of construction, downstream impacts include those resulting from site preparation, demolition of existing structures and/or materials, and general construction waste materials.

E is for...

Earth-Sheltered Design: Design of buildings that are partially or totally below ground. This design uses the constant temperature of the deep earth in a location to improve energy efficiency, and can be beneficial for use of contoured sites by decreasing maintenance and environmental impact.

Ecological Integrity: A natural system exhibits integrity if, when subject to a disturbance, it has a self correcting ability to recover to an end state that is normal for that system, not necessarily one that is pristine or naturally whole.

Ecosystem: The interaction of organisms from the natural community to one another and their environment.

Ecotone: A habitat created by the juxtaposition of distinctly different habitats. An ecological zone or boundary between two or more ecosystems. Also known as edge habitat.

Embodied Energy: Accounts for all energy expended for production and transportation plus inherent energy at a specific point in the life cycle of a product.

Emission: Pollutant gas, particle, or liquid released into the environment.

Energy Management System: A control system capable of monitoring environmental and system loads to adjust HVAC output in order to conserve energy while maintaining comfort.

Energy Recovery Ventilator (ERV): Draws stale air from the building and transfers the heat or coolness in that air to the outside air being pulled into the building. This helps reduce energy costs while improving Indoor Air Quality.

Environmental Restoration: The act of repairing damage to a site caused by human activity, industry, or natural disaster. The ideal is to leave a site in a state that is as close as possible to its natural condition before it was disturbed. Examples are replanting forests, stabilizing soils, and filling in and replanting mine pits.

Evaporative Cooling: The phase change of water from liquid to gas is a heat-absorbing process. The result is effective cooling of the air as water evaporates. This technique can be used to significantly reduce reliance on mechanical refrigeration, particularly in hot, dry climates.

F is for...

Fossil Fuel: Hydrocarbon deposits from plant remnants, including coal, peat, tar sands, shale oil, petroleum, natural gas.

Fungicide: An agent that destroys molds, mildews, yeasts, Includes mercurials (e.g., phenyl mercuric acetate). The destruction of fungi does not necessarily destroy its toxic or allergenic properties.

G is for...

Green Roof: Vegetation cover on roof surfaces. There are two types: 1) Extensive and 2) Intensive.

1) Extensive green roofs (also referred to as eco-roofs or living roofs):
thin soil layer with horizontally spreading, low-growing vegetation cover over entire roof surface that adds minimal loads to structure; serves as ecological stormwater management control by eliminating or delaying runoff. Also effectively reduces temperatures of the roof surface by absorbing heat from the sun, which may reduce the urban heat island effect.
2) Intensive green roofs (also referred to as traditional roof garden): thick soil layer or planters with intensive care and maintenance requiring vegetation, such as trees and shrubs; add substantial loads to building structure.

H is for...

Harvested Rainwater: Rain that falls on a roof or yard and is channeled to a storage tank (cistern) for use.

Hazardous Chemical: Any hazardous material requiring a Material Safety Data Sheet under the Occupational Safety and Health Administration's hazard communication standard, including those associated with physical hazards such as fire and explosion, or health hazards such as cancer and dermatitis.

Heat Recovery: Heat utilized that would otherwise be wasted. Sources of heat include machines, lights, process energy, and people.

Hydrocarbon: Chemical composed only of carbon and hydrogen; petroleum crude oil is largest source of hydrocarbons.

HCFC: Hydrochlorofluorocarbon (HCFC). Typically used to replace CFCs. However, a total ban on all CFCs and HCFCs is scheduled effective 2030. Typically less detrimental to depletion of the stratospheric ozone than related CFCs.

HFC: Hydrofluorocarbon (HFC). Do not have ozone depletion potential, but are greenhouse gases, and contribute to global warming.

I is for...

Impervious Surface: An area that has been sealed and does not allow water to infiltrate, such as roofs, plaza, streets, and other hard surfaces.

Inorganic Compound: Chemical that does not contain carbon as the principal element (except carbonates, cyanides, and cyanates). Minerals, metals, ceramics, and water are examples of inorganic compounds. Most tend to be very stable because they oxidize slowly or not at all.

Insecticide: A chemical agent that destroys insects. These toxins act on the reproductive or nervous system or larval or adult insects.

Insolation: The total amount of solar radiation (direct, diffuse, and reflected) striking a surface exposed to the sky. This incident solar radiation is generally measured in BTU per square foot per hour.

Insulation: Material having resistance to transfer of energy, e.g., acoustic, electric, thermal, vibrational, or chemical.

L is for...

LD50: Measure of toxicity. Amount of a substance that causes death in 50 percent of exposed animals or humans.

Life Cycle Analysis (LCA): A process or framework to evaluate the environmental burdens associated with a product, process, or activity by identifying, quantifying, and assessing its energy and material usage and environmental releases. This process also indentifies opportunities for environmental improvements. Extraction and processing of raw materials, manufacturing, transportation and distribution, use/reuse/maintenance, recycling and final disposal are all considered.

Lumen Method: Used to measure the contribution of daylight to room illumination. Many different variables are taken into account, including sky condition, position of sun, room size, glazing area, and transmission characteristics (such as overhangs, shades, and blinds).

M is for...

MSDS: Material Safety Data Sheet (MSDS). A compilation of information required under the OSHA hazard communication standard, including a listing of hazardous chemicals, health and physical hazards, exposure limits, and handling precautions.

N is for...

Nonrenewable Energy: Sources of energy such as oil, coal, or natural gas that are not replaceable after they have been used.

Nonrenewable Resource: A resource that cannot be replaced in the environment.

O is for...

Old Growth Wood: Wood from trees found in mature forests. In many cases, the trees have never been exposed to logging operations.

Organic Waste: Natural materials, such as food and yard waste, that biodegrade.

P is for...

Particulates: Fine solid particles of dust, spores, pollens, dander, skin flakes, mite allergens, cell debris, mold, mildew, mineral fibers, or solids escaping from combustion processes that are small enough to become suspended in air. Very small particulates (<.005 mm) can be inhaled deep into the lungs. Particulates containing plant or animal proteins (pollens, dust mites, and fungal spores) are allergenic, while those containing mineral fiber (silica, asbestos) can cause lung disease or cancer.

Passive Solar Cooling: Building design that avoids unneeded solar heat, utilizes natural ventilation, and employs thermal mass (especially in hot, dry climates) to retain coolness.

Passive Solar Heating: Building design that uses natural processes to collect, store, and distribute heat for a building. Most passively solar-heated building require an auxiliary heating system for periods when solar heat is unavailable or insufficient.

PBT: Persistent, bio-accumulative toxic pollutant. Highly toxic, long-lasting substances that can build up in the food chain to levels harmful to human and environmental health. EPA has developed a strategy to reduce priority PBT pollutants as part of its source reduction and recycling initiative.

Pervious Paving: Paving material that allows water to penetrate its surface.

Pesticide: Lethal chemical that destroys pests, e.g., insects, rodents, nematodes, fungi, seeds, viruses, or bacteria. Term includes insecticides, herbicide, rodenticide, fungicide, and biocide. Alternative, safe forms of controlling pests include use of sticky or mechanical traps. Many pesticides have been identified by the EPA as persistent, bio-accumulative toxic pollutants.

Pre-Consumer Recycled Content: Material that has been recovered or otherwise diverted from the solid-waste stream during the manufacturing process. Does not include used, reconditioned, or remanufactured components. Also known as Post-Comercial Recycled Content.

Post-Consumer Recycled Content: Material or finished product that has served its intended consumer use and has been discarded for recovery. This material is part of the broader category of recovered material. Examples include newspaper, magazines, beverage containers, building materials, etc.

R is for...

R-Value: Index of the ability of a substance to retard the flow of heat; the higher the numerical value, the higher the insulating value. The inverse of the rate of heat follow (conductivity) through a material.

Radon: Heavy, gaseous radioactive element, produced from decay of radium in soil rocks (e.g., granite, shale, or phosphate). Radon and its decay products are carcinogens.

Rammed Earth: A building technique for exterior walls where earth is tamped down between forms. Certain mixtures of moistened earth used in this technique harden under pressure and form a strong, solid wall that is then covered by a waterproofing coat. Rammed-earth buildings maintain a relatively consistent temperature without artificial heating or cooling due to the thermal mass of earth.

Renewable Resource: A resource that is replenished at a rate equal to or greater than its rate of depletion. Examples of renewable energy resources include solar, wind, hydro, geothermal, and biomass resources. Renewable resources are sometimes referred to as regenerative, non-depletable, or current-income energy.

S is for...

Scheduled Switching: The most basic type of automatic lighting control. Lights are programmed to turn on or off (and brighten or dim) at prescribed times, according to the expected patterns of occupancy.

Shading Coefficient: The ratio of solar energy transmitted through a window to incident solar energy that is normal to it. Used to express the effectiveness of glazing or a shading device.

Sick Building Syndrome (SBS): A pattern of health complaints related to poor indoor air quality. Unlike building-related illness, sick building syndrome does not have known causation or definite symptoms, nor can it be diagnosed medically. Symptoms typically disappear upon leaving the building.

Stack Effect: Pressure-driven airflow produced by convection, by the difference between confined hot gas in chimney or stack and cool air surrounding the outlet. The stack effect can overpower a buildingÕs mechanical system and disrupt ventilation and circulation.

Stack Scrubber: Air pollution control device, used to wash out or remove entrained liquid droplets or dust, or remove undesired gas from process stream. On coal-fired power plants, wet scrubbers are used to reduce sulfur dioxide emissions to control acid rain, using calcium carbonate (limestone) and in the process creating large volumes or waste gypsum, known as synthetic gypsum, which is usable in drywall.

Sulfuric Acid: Very corrosive strong acid, colorless liquid, miscible with water and dissolves most metals. Contributor to acid rain. Used in manufacture of rayon and cellulose, paints and pigments, fertilizers, and explosives.

T is for...

Thermal Chimney: A section of a building where solar heat or thermal currents are controlled in a manner that stimulates an updraft and the exhaust of heated air. This draws fresh air into occupied areas of the building through open windows or vents, providing a passive cooling system.

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 with minimal outdoor influence.

Thermal Mass: Material that absorbs heat or coolness and releases it slowly over a long period of time. Earth, water, and masonry materials can provide excellent thermal mass in passive heating or cooling system design.

Thermal Pollution: Discharge of heated effluent into natural waters that may upset the ecological balance of the waterway due to change in temperature, threatening the survival of some types of life or favoring the survival of others.

V is for...

Ventilation Air: The portion of supply air that has been treated for the purpose of maintaining acceptable indoor air quality.

W is for...

Wind Turbine: A machine that generates electricity from the wind by turning a generator-connected wind propeller.

X is for...

Xeriscape: Landscaping for water and energy efficiency and lower maintenance. The seven xeriscape principles are good planning and design; practical lawn areas; efficient irrigation; soil improvement; use of mulches; low-water-demand plants; good maintenance.