GreenSpec Glossary

A glossary of certifications, measurements, and other not so common terms

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2-year, 24-hour Design Storm: A 2-year, 24-hour design storm is a nationally accepted rate that represents the largest amount of rainfall expected over a 24-hour period during a 2-year interval. The rate is the basis for planning and designing stormwater management facilities and features.
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Account Classification: The method in which suppliers of electricity, natural gas, or fuel oil classify and bill their customers. Commonly used account classifications are"Commercial,""Industrial,"and"Residential."Suppliers'definitions of these terms vary from supplier to supplier and from the definitions used in CBECS. In addition, the same customer may be classified differently by each of its energy suppliers.
ACH: The number of times per hour a volume of air, equivalent to the volume of space, enters that space.
Acid Rain: The precipitation of dilute solutions of strong mineral acids, formed by the mixing in the atmosphere of various industrial pollutants (primarily sulfur dioxide and nitrogen oxides) with naturally occurring oxygen and water vapor.
Acidification: Build-up of acidity in soil and water bodies from acid precipitation, which gains acidity as it falls through an atmosphere containing certain pollutants, especially sulfur dioxide from coal-burning power plants.
Adapted vegetation: Adapted (or introduced) plants reliably grow well in a given habitat with minimal winter protection, pest control, fertilization, or irrigation once their root systems are established. Adapted plants are considered low maintenance and not invasive.
Adaptive Reuse: Adapted reuse is the renovation of a space for a purpose different from the original.
Adequate Transit Service: During weekday peak periods, at least four buses (including bus rapid transit), streetcars or light rail trains per hour OR at least 5 heavy passenger rail or ferries per weekday peak period.
Adjacent Site: A site having at least 25% of its perimeter bordering sites that has been previously developed. Any fraction of the perimeter that borders waterfront will be excluded from the calculation. For the purposes of this definition, a street or roadway does not constitute previously developed land.
Adsorption: The property of many solid surfaces, especially porous ones like carpet or ceiling tile, to attract and retain molecules from the air, for example, volatile organic compounds (VOCs).
Aerosol Adhesive: Aerosol adhesive is an aerosol product in which the spray mechanism is permanently housed in a nonrefillable can. Designed for hand-held application, these products do not need ancillary hoses or spray equipment. Aerosol adhesives include special-purpose spray adhesives, mist spray adhesives, and web spray adhesives. (SCAQMD Rule 1168)
Aggregate Building: A streamlining method. USGBC offers this method only for a few select LEED credits that are often implemented and the results tracked for groups of buildings, i.e., the LEED-EB materials purchasing credits. The volume customer reports the sustainable performance for the whole group or for defined sub-groups, along with its method of verifying that the performance of each building within the group is similar (though not necessarily identical) to that of the group as a whole. Similar performance across the buildings is required; this is NOT intended as a method of simply averaging widely different performance within the group.A credit-level QC plan and Education plan are required for this method.
Agrifiber Board: A composite panel product derived from recovered agricultural waste fiber from sources including, but not limited to, cereal straw, sugarcane bagasse, sunflower husk, walnut shells, coconut husks, and agricultural prunings. The raw fibers are processed and mixed with resins to produce panel products with characteristics similar to those derived from wood fiber.
Agrifiber Products: Agrifiber products are made from agricultural fiber. Examples include particleboard, medium-density fiberboard (MDF), plywood, oriented-strand board (OSB), wheatboard, and strawboard.
AHU: 1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork.
Air Quality Standards: The level of pollutants prescribed by regulations that are not to be exceeded during a given time in a defined area. (EPA)
Air Source Heat Pump: A type of heat pump that extracts heat from the outside air and brings it inside the building. Most heat pumps in use today are air source.
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. (EPA)
Albedo: Albedo is synonymous with solar reflectance.
Alternative Daily Cover: Alternative daily cover is material (other than earthen material) that is placed on the surface of the active face of a municipal solid waste landfill at the end of each operating day to control vectors, fires, odors, blowing litter, and scavenging.
Alternative-fuel Vehicles: Alternative-fuel vehicles use low-polluting, nongasoline fuels such as electricity, hydrogen, propane, compressed natural gas, liquid natural gas, methanol, and ethanol. In LEED, efficient gas-electric hybrid vehicles are included in this group.
Ambient Lighting: Lighting in a space that provides for general wayfinding and visual comfort, in contrast to task lighting, which illuminates a defined area to facilitate specific visual work.
Ambient Temperature: Temperature of the surrounding air or other medium. (EPA)
Ancillary Learning Spaces: Ancillary learning spaces are spaces where good communication is important to a student's educational progress but for which the primary educational functions are informal learning, social interaction or similar activity other than formal instruction. These areas include, but are not limited to, corridors, cafeterias, gymnasia, and indoor swimming pools.
Angle of Maximum Candela: The direction in which the luminaire emits the greatest luminous intensity.
Anticorrosive Paints: Anticorrosive paints are coatings formulated and recommended for use in preventing the corrosion of ferrous metal substrates.
Appurtenance: An appurtenance is any built-in, nonstructural portion of a roof system, such as skylights, ventilators, mechanical equipment, partitions, and solar energy panels.
Area Median Income: The median, or middle, income of a county as defined and available from the U.S. Department of Housing and Urban Development.
Area-weighted SRI: An area-weighted SRI is a weighted average calculation that may be performed for buildings with multiple roof surfaces to demonstrate that the total roof area has an average solar reflectance index equal to or greater than that of a theoretical roof 75% of whose surfaces have an SRI of 78 and 25% have an SRI of 30.
Arid Watershed: Watershed that receives less than 20 inches of rainfall per year.
Assembly Recycled Content: Assembly recycled content is the percentage of material in a product that is either postconsumer or preconsumer recycled content. It is determined by dividing the weight of the recycled content by the overall weight of the assembly.
ASTM: Voluntary standards development organization which creates source technical standards for materials, products, systems, and services
Attendance Boundary: The attendance boundary is used by school districts to determine which students attend what school based on where they live.
Audio Frequency: A sound wave normally audible to humans. Audio frequencies range roughly from 15Hz to 20 kHz.
Automatic Fixture Sensors: Automatic fixture sensors are motion detectors that automatically turn on and turn off lavatories, sinks, water closets, and urinals. Sensors can be hard wired or battery operated.
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Baseline Building Performance: Baseline building performance is the annual energy cost for a building design intended for use as a baseline for rating above standard design, as defined in ANSI/ASHRAE/IESNA Standard 90.12007, Informative Appendix G.
Baseline Irrigation Water Use: Baseline irrigation water use is the amount of water used by conventional irrigation in the region.
bay: A bay is a component of a standard, rectilinear building design. It is the open area defined by a building element such as columns or a window. Typically, there are multiple identical bays in succession.
BIFMA: A multiple-attribute level, third-party certification, and label for commercial furniture with three tiers, level 3 being the most rigorous, based on points earned but with no prerequisites.
Biking Network: A continuous network consisting of one or more of the following: bicycle lanes or trails at least 5 feet wide or roads designed for a speed of 10 miles per hour or slower.
Binder: Glue used in manufacturing wood products, such as medium-density fiberboard (MDF), particleboard, and engineered lumber. Most binders are made with formaldehyde.
Bioaccumulation: Process by which toxins can build up progressively through the food chain; small organisms often store toxins in fat tissue, and when larger organisms eat them, those toxins became more concentrated.
Biobased: Generally, classification of products and materials derived from plant and animal sources as opposed to minerals. The U.S. Department of Agriculture has a program to promote the use of emerging biobased products that defines them more narrowly, to exclude products that already have established markets, such as food, animal feed, and lumber.
Biochemical Oxygen Demand: Biochemical oxygen demand is a measure of how fast biological organisms use up oxygen in a body of water. It is used in water quality management and assessment, ecology, and environmental science.
Biological Control: Biological control is the use of chemical or physical water treatments to inhibit bacterial growth in cooling towers.
Bioremediation: The use of microorganisms and vegetation to remove contaminants from water and soils. Bioremediation is generally a form of in-situ remediation and can be a viable alternative to landfilling or incineration.
BIPV: Building-integrated photovoltaic systems use photovoltaic (PV) modules that are integrated into functional building elements, such as roofs, glazing, and building façades.
Bisphenol-A: An ingredient in the production of polycarbonate plastics that is a suspected endocrine disrupter. Also known as BPA.
Blackwater: Blackwater definitions vary, but wastewater from toilets and urinals is always considered blackwater. Wastewater from kitchen sinks (perhaps differentiated by the use of a garbage disposal), showers, or bathtubs is considered blackwater under some state or local codes.
Bleed-off: Bleed-off, or blowdown, is the release of a portion of the recirculating water from a cooling tower; this water carries dissolved solids that can cause mineral buildup.
Bleed-off Rate: The frequency with which the dissolved minerals and dirt are removed from the cooling tower. It varies depending on the mineral content and scaling tendency of the entering water.
Blowdown: Bleed-off, or blowdown, is the release of a portion of the recirculating water from a cooling tower; this water carries dissolved solids that can cause mineral buildup.
Blower door test: A blower door test gives an overall value for airtightness of a space, and can help identify air leaks. The testing unit consists of a calibrated fan that is sealed onto the unit entrance. The fan creates a continuous flow of pressure into the unit (or out of the unit when using theatrical fog to locate leaks). Devices detect the rate of pressure retention and loss due to possible air leaks in the construction.
BMP: Best Management Practice
BOD: Basis of design (BOD) includes design information necessary to accomplish the owner's project requirements, including system descriptions, indoor environmental quality criteria, design assumptions, and references to applicable codes, standards, regulations, and guidelines.
Breathing Zone: The breathing zone is the region within an occupied space between 3 and 6 feet above the floor and more than 2 feet from walls or fixed air-conditioning equipment. (AHSRAE 62.12007)
BREEAM: Building Research Establishment Environmental Assessment Method, the first widely used green building rating system, developed in the U.K. in the early 1990s, currently used primarily in the U.K. and in Hong Kong.
Brownfields: Abandoned, idled, or under used industrial and commercial facilities/sites where expansion or redevelopment is complicated by real or perceived environmental contamination (may include hazardous substances, pollutants, or contaminants). They can be in urban, suburban, or rural areas. EPA's Brownfields initiative helps communities mitigate potential health risks and restore the economic vitality of such areas or properties. (EPA)
Btu: A unit of energy consumed by or delivered to a building. A Btu is an acronym for British thermal unit and is defined as the amount of energy required to increase the temperature of 1 pound of water by 1 degree Fahrenheit, at normal atmospheric pressure. Energy consumption is expressed in Btu to allow for consumption comparisons among fuels that are measured in different units.
Buildable Land: The portion of the site where construction can occur. When used in density calculations, the calculation for buildable land excludes: public streets and other public rights of way, and land excluded from development by law or other prerequisites of LEED for Neighborhood Development.
Building Automation System (BAS): A building automation system (BAS) uses computer-based monitoring to coordinate, organize, and optimize building control subsystems, including lighting, equipment scheduling, and alarm reporting.
Building Density: Building density is the floor area of the building divided by the total area of the site (square feet per acre).
Building Engineer: A qualified engineering professional with relevant and sufficient expertise who oversees and is responsible for the operation and maintenance of mechanical, electrical and plumbing systems in the project building.
Building Floorspace: All the area enclosed by the exterior walls of a building, both finished and unfinished, including indoor parking facilities, basements, hallways, lobbies, stairways, and elevator shafts. For aggregate floorspace statistics, floorspace was summed or aggregated over all buildings in a category (such as all office buildings in the United States).
Building Footprint: Building footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint.
Building Operating Plan: A general documentation summarizing the intended operation of each base building system described in the systems narrative; the building operating plan may also be known as"Owner's Operating Requirements"or similar. The operating plan includes the time-of-day schedules for each system for each of the eight day types (Monday to Sunday plus holidays), the mode of operation for each system when it is running (occupied vs. unoccupied; day vs. night, etc.), and the desired indoor conditions or setpoints for each schedule or mode. The operating plan accounts for any differences in needs or desired conditions for different portions of the project building, as well as any seasonal variations in operations patterns. The plan accounts for all the monitored space conditions used to control the base systems, i.e., air temperature, relative humidity, occupancy, light level, CO2 levels, room pressurization, duct static pressure, etc.
Building Shell: The exterior walls, roof, and lowest floor of a building, which serve to separate and protect the interior from the elements (precipitation, sunlight, wind, temperature variations).
Building-Related Illness: Diagnosable illness whose cause and symptoms can be directly attributed to a specific pollutant source within a building. (EPA)
Buildout: The time at which all habitable buildings on the project are complete and ready for occupancy.
Built-Up Roof: A roof covering consisting of several successive layers (each of which is called a"ply"), usually of roofing felt, with mopping of hot asphalt between layers and topped by a mineral-surfaced layer or by gravel embedded in a heavy coat of asphalt.
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C&D: Construction and demolition
C2C: A protocol developed by McDonough Braungart Design Chemistry that establishes guidelines for the manufacture of products in ways that harmonize with natural systems. These guidelines require, for example, that products be recyclable indefinitely, contain no hazardous ingredients, and be manufactured using renewable energy.
Cadmium: A naturally-occurring element and source of pigments that were once a staple in paints, but now is largely phased out in architectural coatings except for certain specialty products. High exposure to cadmium can cause a variety of health problems, including kidney damage.
California Section 01350: A leading emissions specification on which many other U.S. certifications are based. Test methods ensure pollutant concentrations in a finished space do not exceed certain levels.
Campus Bus: A campus or private bus is a bus or shuttle service that is privately operated and not available to the general public. In LEED, a campus or private bus line that falls within 1/4 mile of the project site and provides transportation service to the public can contribute to earning credits.
Car Sharing: A system under which multiple households share a pool of automobiles, either through cooperative ownership or through some other mechanism.
CARB: The California Air Resources Board, part of the state government, is charged with maintaining clean air. This agency is unique at the state level: California was the only state that had such an agency before the passage of the federal Clean Air Act, and was allowed to keep it.
Carbon offset: A fiscal unit measured in metric tons of carbon dioxide-equivalent (CO2e) representing six main categories of greenhouse gases. Aimed at reducing greenhouse gas emissions, one carbon offset represents the reduction of one metric ton of carbon dioxide (or its equivalent in other greenhouse gases). Carbon offsets are typically purchased by consumers of fossil fuels or products using fossil fuels, as a way to"offset"or negate their negative environmental impact.
Cases or Cabinets: Refrigeration in open or closed units for the purpose of selling, displaying, or storing perishable materials."Open"refers to cases or cabinets with no covers or with flexible covers made of plastic or some other material, hung in strips or curtains to stop the flow of warm air into the refrigerated space. Examples of open cases are produce, dairy, and deli cases, salad bars, and sandwich preparation units."Closed"refers to units with doors that shut, such as beverage display coolers, grocery coolers or freezers, dessert displays, under-counter coolers, floral display coolers, and ice machines.
CBECS: The Commercial Buildings Energy Consumption Survey (CBECS) is a national sample survey that collects information on the stock of U.S. commercial buildings, their energy-related building characteristics, and their energy consumption and expenditures. Commercial buildings include all buildings in which at least half of the floorspace is used for a purpose that is not residential, industrial, or agricultural, so they include building types that might not traditionally be considered"commercial,"such as schools, correctional institutions, and buildings used for religious worship. CBECS data is used in LEED energy credits.
CDD: A measure of how hot a location was over a period of time, relative to a base temperature. In this report, the base temperature is 65 degrees Fahrenheit, and the period of time is one year. The cooling degree-day is the difference between that day's average temperature and 65 degrees if the daily average is greater than 65; it is zero if the daily average temperature is less than or equal to 65. Cooling degree-days for a year are the sum of the daily cooling degree-days for that year.
CDL: Construction, demolition, and land-clearing (CDL) debris includes all of the above plus soil, vegetation, and rock from land clearing.
CEE: The nonprofit Consortium for Energy Efficiency (CEE) develops standards beyond Energy Star for a wide range of high-efficiency equipment. CEE typically outlines three performance tiers, tier 3 being the most efficient.
CERCLA: The Comprehensive Environmental Response, Compensation, and Liability Act, or CERCLA, is more commonly known as Superfund. Enacted in 1980, CERCLA addresses abandoned or historical waste sites and contamination by taxing the chemical and petroleum industries and providing federal authority to respond to releases of hazardous substances.
Certified Wood: Wood from a source that has been determined, through a certification process, to meet stated ecological and other criteria. There are numerous forest certification programs in general use based on several standards, but only the Forest Stewardship Council's standards, which include requirements that the wood be tracked through its chain-of-custody, can be used to qualify wood for a point in the LEED Rating System.
CFCs: Chlorofluorocarbons (CFCs) are hydrocarbons that are used as refrigerants and cause depletion of the stratospheric ozone layer.
CFL: 1. Compact fluorescent lamp (CFL) light source in which the tube is folded or twisted into a spiral to concentrate the light output; CFLs are typically 3 to 4 times as efficient as incandescent light bulbs, and they last 8 to 10 times as long. 2. Small fluorescent lamps used as more efficient alternatives to incandescent lighting. Also called PL, CFL, Twin-Tube, or BIAX lamps. (EPA) 3. A light bulb designed to replace screw-in incandescent light bulbs; they are often found in table lamps, wall sconces, and hall and ceiling fixtures of commercial buildings with residential type lights. They combine the efficiency of fluorescent lighting with the convenience of standard incandescent bulbs. Light is produced the same way as other fluorescent lamps. Compact fluorescent bulbs have either electronic or magnetic ballasts.
CGP: EPA's Construction General Permit. Outlines the provisions necessary to comply with Phase I and Phase II of the National Pollutant Discharge Elimination System (NPDES) program.
Chain-of-Custody: Chain-of-custody (COC) is a tracking procedure for a product from the point of harvest or extraction to its end use, including all successive stages of processing, transformation, manufacturing, and distribution.
Chemical Runoff: Water that transports chemicals from the building landscape, as well as surrounding streets and parking lots, to rivers and lakes. Runoff chemicals may include gasoline, oil, antifreeze, and salts.
Chemical Treatment: Chemical treatment includes the use of biocidal, conditioning, dispersant, and scale-inhibiting chemicals to control biological growth, scale, and corrosion in cooling towers. Alternatives to conventional chemical treatment include ozonation, ionization, and exposure to ultraviolet light.
CHP: Combined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source.
Chromium: A naturally occurring metal used to make chrome, used in some wood treatment compounds, and sometimes used to tan leather. Its usage has been greatly reduced, but it may still be found in some products. Although chromium is an essential nutrient, some chromium compounds are carcinogenic.
Churn: 1. Churn is the movement of workstations and people within a space.2. The reorganization of office space due to relocation of an employee from one workstation to another, employee turnover, or reorganization of an entire office.
CIGS: Copper indium gallium diselenide is a type of thin-film photovoltaic (PV) material.
CIR: Credit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide
Circadian Rhythm: The rhythm of an organism's vital functions with relation to the daily cycle of the natural environment.
Class I Bikeway: Bicycle or multi-use facilities that are completely separate from the vehicular right-of-way. The standard Class I bikeway has pavement that is 8 feet wide however the exact design requirements for Class I bikeways differ from jurisdiction to jurisdiction.
Clerestory Windows: Pronounced and sometimes spelled"clear-story,"these are vertical, or close-to-vertical, windows high in the wall of a building that bring daylight deeply into the building and, if operable, can help ventilate the space.
Climate Change: 1. Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). (U.S. Environmental Protection Agency, 2008)2.The increase in global average temperatures being caused by a buildup of CO2 and other greenhouse gases in the atmosphere. This temperature change is leading to changes in circulation patterns in the air and in the oceans, which are affecting climates differently in different places. Among thepredicted effects are a significant cooling in Western Europe due to changes in the jet stream, and rising sea levels due to the melting of polar ice and glaciers.
Climate Zone: One of five climatically distinct areas, defined by long-term weather conditions which affect the heating and cooling loads in buildings. The zones were determined according to the 45-year average (1931-1975) of the annual heating and cooling degree-days (base 65 degrees Fahrenheit). An individual building was assigned to a climate zone according to the 45-year average annual degree-days for its National Oceanic and Atmospheric Administration (NOAA) Division.
CO2: Carbon dioxide
Cogeneration: The simultaneous production of electric and thermal energy in on-site, distributed energy systems; typically, waste heat from the electricity generation process is recovered and used to heat, cool, or dehumidify building space. Neither generation of electricity without use of the byproduct heat, nor waste-heat recovery from processes other than electricity generation is included in the definition of cogeneration.
Comfort Criteria: Comfort criteria are specific design conditions that take into account temperature, humidity, air speed, outdoor temperature, outdoor humidity, seasonal clothing, and expected activity. (ASHRAE 552004)
Comingled: A process of recycling materials that allows consumers to dispose of various materials (such as paper, cardboard, plastic, and metal) in one container that is separate from waste. The recyclable materials are not sorted until they are collected and brought to a sorting facility.
Completed Design Area: Completed design area is the total area of finished ceilings, floors, full-height walls and demountable partitions, interior doors, and built-in case goods in the completed project. It does not include exterior windows and doors.
Composite Wood: Composite wood consists of wood or plant particles or fibers bonded by a synthetic resin or binder. Examples include particleboard, medium-density fiberboard (MDF), plywood, oriented-strand board (OSB), wheatboard, and strawboard.
Composting Toilets: Composting (or Nonwater) toilet systems are dry plumbing fixtures and fittings that contain and treat human waste via microbiological processes.
Compressed Workweek: A compressed workweek rearranges the standard workweek (5 consecutive 8-hour days in a week), increasing the daily hours and decreasing the number of days in the work cycle. For example, instead of working 8-hour days Monday through Friday, employees work 10-hour days for 4 days per week, or 9-hour days for 9 of 10 consecutive days.
Concentration Ratio: Concentration ratio is the ratio of the level of dissolved solids in the recirculating water to the level found in the entering makeup water. A higher concentration ratio results from a lower bleed-off rate; increasing the ratio above a certain point, however, leads to scaling, and water savings diminish after a certain level. This ratio is also called the cycles of concentration. Cycles refers to the number of times dissolved minerals in the water are concentrated compared with makeup water, not to water flow over the tower or to on-off cycles.
Conditional Energy Intensity: Total consumption of a particular energy source(s) or fuel(s) divided by the total floorspace of buildings that use the energy source(s) or fuel(s), i.e., the ratio of consumption to energy source-specific floorspace. This measure is used in the fuel-specific detailed tables.
Conductivity Meter: A device that measures the amount of nutrients and salt in water. Also know as a EC meter.
Construction General Permit: EPA's Construction General Permit. Outlines the provisions necessary to comply with Phase I and Phase II of the National Pollutant Discharge Elimination System (NPDES) program.
Construction IAQ Management Plan: A construction IAQ management plan outlines measures to minimize contamination in a specific project building during construction and describes procedures to flush the building of contaminants prior to occupancy.
Construction Scope: ?
Construction Waste Management Plan (CWMP): A plan that diverts construction debris from landfills through the processes of recycling, salvaging and reusing.
Conversion Factors: Estimates are presented in customary U.S. units. Floorspace estimates may be converted to metric units by using the relationship: 1 square foot is approximately equal to 0.0929 square meters. Energy estimates may be converted to metric units by using the relationship: 1 Btu is approximately equal to 1,055 joules; one kilowatthour is exactly equal to 3,600,000 joules; and one gigajoule (109 joules) is approximately 278 kilowatthours (kWh).
Conversion Losses: The amount of energy lost during generation, transmission, and distribution of energy sources, particularly electricity, including plant and unaccounted-for uses.
Cooling Equipment: The equipment used for cooling room air in a building for human comfort.
Core learning spaces: Core learning spaces are spaces for educational activities where the primary functions are teaching and learning and where good speech communication is critical to a student's academic achievement. These spaces include, but are not limited to, classrooms, enclosed or open plan), instructional pods or activity areas, group instruction rooms, conference rooms, libraries, offices, speech clinics, offices used for educational purposes and music rooms for instruction, practice and performance.
Cradle to Cradle Biological Nutrient: C2C is a multi-attribute certification based on MBDC’s Cradle to Cradle (C2C) philosophy. The biological nutrient label recognizes simple products that meet C2C materials requirements only.
Cradle to Cradle Gold: C2C is a multiple-attribute certification and label, based on MBDC’s Cradle to Cradle (C2C) philosophy, with five performance tiers of varied levels of stringency. Gold is the second-highest level.
Cradle to Cradle Platinum: C2C is a multiple-attribute certification and label, based on MBDC’s Cradle to Cradle (C2C) philosophy, with five performance tiers of varied levels of stringency. Platinum is the highest achievement level.
Cradle to Cradle Silver: C2C is a multiple-attribute certification and label, based on MBDC’s Cradle to Cradle (C2C) philosophy, with five performance tiers. The Silver tier does not require phase-out of identified hazardous chemicals.
Cradle to Cradle Technological Nutrient: C2C is a multi-attribute certification based on MBDC’s Cradle to Cradle (C2C) philosophy. The technological nutrient label recognizes simple products that meet C2C materials requirements only.
CRI: Color-rendering index, or CRI, is a scale of 0 to 100, used by manufacturers of fluorescent, metal halide, and other non-incandescent lighting equipment to describe the visual effect of the light on colored surfaces. Natural daylight is assigned a CRI of 100.
CRI Green Label: Green Label, developed by the Carpet and Rug Institute in 1992, is a second-party indoor air quality certification and label for carpet cushion.
CRI Green Label Plus: Green Label Plus, managed by the Carpet and Rug Institute, is a certification established for carpet and carpet adhesive that meet the California Section 01350 emissions standard.
Cx: 1. Commissioning (Cx) is the process of verifying and documenting that a building and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner's project requirements.2. The process of checking the performance of a building against the owner's goals during design, construction, and occupancy. At a minimum, mechanical and electrical equipment are tested, although much more extensive testing may also be included.
CxA: The commissioning authority (CxA) is the individual designated to organize, lead, and review the completion of commissioning process activities. The CxA facilitates communication among the owner, designer, and contractor to ensure that complex systems are installed and function in accordance with the owner's project requirements.
Cycles of Concentration: Concentration ratio is the ratio of the level of dissolved solids in the recirculating water to the level found in the entering makeup water. A higher concentration ratio results from a lower bleed-off rate; increasing the ratio above a certain point, however, leads to scaling, and water savings diminish after a certain level. This ratio is also called the cycles of concentration. Cycles refers to the number of times dissolved minerals in the water are concentrated compared with makeup water, not to water flow over the tower or to on-off cycles.
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Daylight Factor: The ratio of exterior illumination to interior illumination, expressed as a percentage. The variables used to determine the daylight factor include the floor area, window area, window geometry, visible transmittance (Tvis), and window height.
Daylight Glazing: A vertical window area located 7'6"above the floor. Glazing at this height is the most effective at distributing daylight deep into the interior space.
Daylight-Responsive Lighting Controls: Daylight-responsive lighting controls are photosensors used in conjunction with other switching and dimming devices to control the amount of artificial lighting in relationship to the amount and quality of natural daylight.
Daylighting Sensors: A lighting feature that takes advantage of sunlight to cut the amount of electric lighting used in a building by varying output of the lighting system in response to variations in available daylight. They are sometimes referred to as"natural lighting control sensors"or"photocells."
dBA: A decibel (dBA) is a sound pressure level measured with a conventional frequency weighting that roughly approximates how the human ear hears different frequency components of sounds at typical listening levels for speech. (ANSI S12.602002)
Declarant: A LEED project team member who is technically qualified to verify the content of a LEED credit submittal template, and is authorized by the project administrator to sign the template and upload it to LEED Online. The Declarant must have had asignificant degree of responsibility for the credit, such as participation in or oversight of the implementation or verification. The declarant for credits may be restricted or nonrestricted. For example, for Sustainable Sites Credit 4, only the property manager or facility manager may submit verification; for others, any team member, including contractors or consultants, can prepare the submittal documentation.
Dedicated Server: A server is usually just the CPU or"case"portion of a computer that is used to manage network resources such as computer files, printers, databases, or network traffic; it does not require much human operation, so most do not have keyboards or monitors."Dedicated"means that the server performs no other tasks besides server tasks.
Degree-Days 45-Year Average: The average of the total annual heating and cooling degree-days (base, 65 Degrees Fahrenheit) in each NOAA Division, for the 45 years, 1931 through 1975. Computed from the Division's daily temperature averages for each year in question and used to assign individual buildings to climate zones.
Densely Occupied Spaces: Densely occupied spaces are areas with a design occupant density of 25 people or more per 1,000 square feet (40 square feet or less per person).
Density Factor: Density factor (kd) is a coefficient used in calculating the landscape coefficient. It modifies the evapotranspiration rate to reflect the water use of a plant or group of plants, particularly with reference to the density of the plant material.
Depth of Discharge: The percentage of storage capacity discharged from a battery. The percentage of the battery capacity that is "used" and not currently storing energy. If a battery is currently holding 30% of its capacity, it is at 70% depth of discharge.
Design Intent: A written document that details the ideas, concepts, and criteria that are determined by the owner to be important to the success of the project.
Design Light Output: Design light output is the light output of lamps at 40% of their useful life.
Development Footprint: The development footprint is the area affected by development or by project site activity. Hardscape, access roads, parking lots, nonbuilding facilities, and the building itself are all included in the development footprint.
DHW: Domestic hot water (DHW) is water used for food preparation, cleaning and sanitation and personal hygiene, but not heating.
Differential air pressure: The difference in air pressure between two spaces, potentially leading, in the case of a pressure difference, to the migration of contaminants from one space to another. When using a designated smoking room ror environmental tobacco smoke control, you may need to test the differential air pressure in the smoking room with respect to each adjacent area and in each adjacent vertical chase with the doors to the smoking room closed. The testing will be conducted with each space configured for worst case conditions of transport of air from the smoking rooms to adjacent spaces with the smoking rooms'doors closed to the adjacent spaces. The test can be conducted by a mechanical engineer. The test should involve 15 minutes of measurement, with a minimum of one measurement every 10 seconds. With the doors to the smoking room closed, operate exhaust sufficient to create a negative pressure with respect to the adjacent spaces of at least an average of 5 Pa (0.02 inches of water gauge) and with a minimum of 1 Pa (0.004 inches of water gauge).
Diffusers: In an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light.
Direct Line of Sight to Perimeter Vision Glazing: The approach used to determine the calculated area of regularly occupied areas with direct line of sight to perimeter vision glazing. The area determination includes full height partitions and other fixed construction prior to installation of furniture.
Displacement Ventilation: A system in which air slightly cooler than the desired room temperature is introduced at floor level and is lifted up by warmer air to exhaust outlets at the ceiling, increasing air circulation and removal of pollutants.
Distributed Water-Heating System: A type of system for heating water (for purposes other than space-heating) that heats water as needed for immediate use near the location where this water is used. It is often called a"point-of-use"water heating system, and is usually located in more than one place within a building. Because water is not heated until it is required, this equipment is more energy efficient.
Downstream Equipment: Downstream equipment consists of all heating or cooling systems, equipment, and controls located within the project building and site associated with transporting thermal energy into heated or cooled spaces. This includes the thermal connection or interface with the district energy system, secondary distribution systems in the building, and terminal units.
Drip Irrigation: Drip irrigation delivers water at low pressure through buried mains and submains. From the submains, water is distributed to the soil through a network of perforated tubes or emitters. Drip irrigation is a high-efficiency type of microirrigation.
Dual-flush: A type of water-saving toilet that gives a choice of flushes depending on the type of waste solid or liquid.
Durable Goods: Durable goods have a useful life of 2 years or more and are replaced infrequently or may require capital program outlays. Examples include furniture, office equipment, appliances, external power adapters, televisions, and audiovisual equipment.
Durable Goods Waste Stream: The durable goods waste stream consists of durable goods leaving the project site that are fully depreciated and have reached the end of their useful lives for normal business operations.
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EBOM: EBOM is an acronym for Existing Buildings: Operations&Maintenance, one of the LEED 2009 rating sytems.
EC Meter: A device that measures the amount of nutrients and salt in water. Also know as a Conductivity Meter.
ECM: Energy conservation measures are installations or modifications of equipment or systems intended to reduce energy use and costs.
Ecological Restoration: Ecological restoration is the process of assisting in the recovery and management of ecological integrity and includes biodiversity, ecological processes and structures, regional and historical context, and sustainable cultural practices.
Ecologically Appropriate Site Features: Ecologically appropriate site features are natural site elements that maintain or restore the ecological integrity of the site. Examples include native or adapted vegetation, water bodies, exposed rock, unvegetated ground, and other features that provide habitat value and are part of the historic natural landscape.
EcoLogo: A third-party multi-attribute certification program established in 1988 and backed, but not run, by the Canadian government. This certification is based on a specific standard for each product type.
Economizer: An economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature.
Economizer Cycle: A heating, ventilation, and air-conditioning (HVAC) conservation feature consisting of indoor and outdoor temperature and humidity sensors, dampers, motors, and motor controls for the ventilation system to reduce the air-conditioning load. Wherever the temperature and humidity of the outdoor air are more favorable (lower heat content) than the temperature and humidity of the return air, more outdoor air is brought into the building.
Ecotoxicity: Generally, harmful effects produced in the environment by chemical residues, leachate, or volatile gases during production or degradation of manufactured materials. Specifically, the measured levels at which toxins cause harm to organisms.
EF: Energy factor (EF) measures energy conversion efficiencies of appliances or equipment. For example, for water heaters, EF is the ratio of useful energy output to the total amount of energy delivered—higher is better.
Efficacy: In lighting, the ratio of light output (in lumens) to input power (in watts). Higher efficacy indicates higher efficiency.
Electrical Conductivity (EC) Meter: An electrical conductivity (EC) meter measures the amount of nutrients and salt in water.
Electrical Engineering: Electrical and electronics engineering is the practical application of electricity. Electrical engineers are concerned with electrical devices and systems and with the use of electrical energy.
Embodied Energy: 1. Embodied energy is the energy used during the entire life cycle of a product, including its manufacture, transportation, and disposal, as well as the inherent energy captured within the product itself.2. The energy expended in the process of creating a product, often including the fuel value of its constituent parts as well as transportation to its point of use.
EMCS: Energy Management and Control System (EMCS) is an energy management feature that uses mini/microcomputers, instrumentation, control equipment, and software to manage a building's use of energy for heating, ventilation, air conditioning, lighting, and/or business-related processes. These systems may also manage fire control, safety, and security. Not included as an EMCS are time-clock thermostats.
emergency lighting: Emergency lighting as defined by the Illuminating Engineering Society of North America is lighting designed to supply illumination essential to the safety of life and property in the event of failure of the normal supply.
Emissivity: Emissivity is the ratio of the radiation emitted by a surface to the radiation emitted by a black body at the same temperature.
Endocrine Disrupter: Chemical that mimics natural hormones, such as estrogen, and may interfere with reproductive development or alter behavior in offspring. Among common chemicals believed to be endocrine disrupters are phthalate plasticizers used in PVC plastic and bisphenol-A, which is used in the manufacture of epoxies and polycarbonate plastic.
Energy Intensity: The ratio of consumption to unit of measurement (floorspace, number of workers, etc.) Energy intensity is usually given on an aggregate basis, as the ratio of the total consumption for a set of buildings to the total floorspace in those buildings. Conditional energy intensity and gross energy intensity are presented. The energy intensity can also be computed for individual buildings.
Energy Source-Specific Floorspace: Total floorspace of those buildings that use a particular fuel, for example, total floorspace in buildings that use natural gas.
Energy Star: A popular government-sponsored product certification and label established in 1992 for energy efficient products and energy-efficient buildings.
Energy-Related Space Functions: The use of space in the building for one or more of three specific functions: commercial food preparation, activities requiring large amounts of hot water, and separate computer areas.
Environmentally Preferable Purchasing: A United States federal-wide program (Executive Order 13101) that encourages and assists Executive agencies in the purchasing of Environmentally Preferable Products and services.
EPA WaterSense: A government-sponsored product certification and label established in 2006 for water-efficient products and water-efficient new buildings.
EPP: Environmentall preferable products (EPP) are those identified as having a lesser or reduced effect on health and the environment when compared with competing products that serve the same purpose.
ESC: An Erosion and Sedimentation Control (ESC) plan is a collection of measures designed to reduce pollution from construction activities by controlling soil erosion, waterway sedimentation and airborne dust generation
ET: Evapotranspiration (ET) is the loss of water by evaporation from the soil and by transpiration from plants. It is expressed in millimeters per unit of time.
ETS: Environmental tobacco smoke (ETS), or secondhand smoke, consists of airborne particles emitted from the burning end of cigarettes, pipes, and cigars, and is exhaled by smokers. These particles contain about 4,000 compounds, up to 50 of which are known to cause cancer.
Eutrophication: 1. Eutrophication is the increase in chemical nutrients, such as the nitrogen and phosphorus often found in fertilizers, in an ecosystem. The added nutrients stimulate excessive plant growth, promoting algal blooms or weeds. The enhanced plant growth reduces oxygen in the land and water, reducing water quality and fish and other animal populations.2. The process by which bodies of water are starved of oxygen and light by algae and other plants that multiply due to excessive concentrations of nutrients such as nitrogen and phosphorous. Typical sources include fertilizer runoff and poorly managed wastewater treatment systems, frequently including home septic systems.
Ex-situ Remediation: The removal and treatment of contaminated soil and groundwater. Treatment of the contaminated media occurs in another location, typically a treatment facility. A traditional method of ex-situ remediation is pump-and-treat technology that uses carbon filters and incineration. More advanced methods of ex-situ remediation include chemical treatment or biological reactors.
Exemplary performance: In LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements.
Exfiltration: Exfiltration is air leakage through cracks and interstices and through the ceilings, floors, and walls.
External Overhangs or Awnings: A conservation feature designed to reduce the transmission of light into a building. These include any type of overhang (including architectural) or awning on the outside of the building designed to limit solar penetration.
Extraction, harvest or recovery point: Extraction, harvest or recovery point refers to the location of raw materials prior to manufacturing of the building material or product that is furnished and installed in the project building.
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Faucet aerator: A device designed to save water and reduce splashing by adding air to a stream of water; usually found at the tip of a faucet.
fc: 1. A footcandle (fc) is a measure of light falling on a given surface. One footcandle is defined as the quantity of light falling on a 1-square-foot area from a 1 candela light source at a distance of 1 foot (which equals 1 lumen per square foot). Footcandles can be measured both horizontally and vertically by a footcandle meter or light meter.2. The non-metric measurement of lumens per square foot, one footcandle is the amount of light that is received one foot from a light source called a candela, which is based on the light output of a standardized candle. A common range for interior lighting is 10 to 100 footcandles, while exteriordaytime levels can range from 100 to over 10,000 footcandles. Footcandles decrease with distance from the light source. The metric equivalent of a foot candle is 10.76 lux, or lumens per square meter.
Flat Coatings: Coatings that register a gloss of less than 15 on an 85-degree meter or less than 5 on a 60-degree meter.
Floor Area Ratio: Floor Area Ratio (FAR) is the measure of the density of non-residential land use. It is the total non-residential building floor area divided by the total buildable land area available for non-residential uses. For example, on a site with 10,000 square feet of buildable land area, an FAR of 1.0 would be 10,000 square feet of built building floor area. On the same site, an FAR of 1.5 would be 15,000 square feet ofbuilt floor area; an FAR of 2.0 would be 20,000 built square feet and an FAR of 0.5 would be 5,000 built square feet.
FloorScore: A third-party indoor air quality certification and label established in 2005 for low emitting hard-surface flooring products that meet California Section 01350 requirements.
Fluoropolymer: A polymer (compound made up of many identical molecules linked by chemical bonds) containing the element fluorine; the most recognized fluoropolymer is polytetrafluoroethylene (PTFE), sold under DuPont's Teflon trademark. A key constituent in making some fluoropolymers, perfluorooctanoic acid (PFOA), has come under scrutiny as a"likely carcinogen."
Flushometer: A device that utilizes pressure from the water supply system, rather than the force of gravity, to discharge water into the bowl of a toilet or urinal. It is designed to use less water than conventional flush toilets.
Forest Stewardship Council (FSC): FSC is a third-party certification established in 1993 for responsible forestry and the resulting wood products. FSC is well-respected among the environmental movement.
Formaldehyde: 1. Formaldehyde is a naturally occurring VOC found in small amounts in animals and plants but is carcinogenic and an irritant to most people when present in high concentrations, causing headaches, dizziness, mental impairment, and other symptoms. When present in the air at levels above 0.1 ppm, it can cause watery eyes; burning sensations in the eyes, nose, and throat; nausea; coughing; chest tightness; wheezing; skin rashes; and asthmatic and allergic reactions.2. A known carcinogen with no known safe exposure level. Formaldehyde occurs naturally, but appears in unnaturally high concentrations in many buildings because it is an ingredient in binders used in many building materials and furnishings.
FSC: Independent, third-party verification that forest products are produced and sold based on a set of criteria for forest management and chain-of-custody controls developed by the Forest Stewardship Council (FSC), an international nonprofit organization. FSC criteria for certifying forests around the world address forest management, legal issues, indigenous rights, labor rights, multiple benefits, and environmental impacts.
FTE: Full-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE.Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix.All occupant assumptions must be consistent across all credits in all categories.
Fuel-Efficient Vehicles: Fuel-efficient vehicles have achieved a minimum green score of 40 according to the annual vehicle-rating guide of the American Council for an Energy Efficient Economy.
Full Cutoff: A full cutoff luminaire has zero candela intensity at an angle of 90 degrees above the vertical axis (nadir or straight down) and at all angles greater than 90 degrees from straight down. Additionally, the candela per 1,000 lamp lumens does not numerically exceed 100 (10%) at an angle of 80 degrees above nadir. This applies to all lateral angles around the luminaire.
Full Cutoff Luminaire: A full cutoff luminaire has zero candela intensity at an angle of 90 degrees above the vertical axis (nadir or straight down) and at all angles greater than 90 degrees from straight down. Additionally, the candela per 1,000 lamp lumens does not numerically exceed 100 (10%) at an angle of 80 degrees above nadir. This applies to all lateral angles around the luminaire.
Full-Cost Accounting: A method of monetizing the environmental and social impacts, as well as financial costs, associated with a product or process.
Full-Time Equivalent: Full-time equivalent (FTE) represents a regular building occupant who spends 40 hours per week in the project building. Part-time or overtime occupants have FTE values based on their hours per week divided by 40. Multiple shifts are included or excluded depending on the intent and requirements of the credit.
Fully Shielded: In a fully shielded exterior light fixture, the lower edge of the shield is at or below the lowest edge of the lamp, such that all light shines down.
Functional Entry: An entryway that is designed to be used by pedestrians and is open during regular business hours. This does not include any door that is exclusively designated as an emergency exit, or a garage door that is not designed as an entrance for pedestrians.
Functional Performance Testing: The process of determining the ability of the commissioned systems to perform in accordance with the owner's project requirements, basis of design (BOD), and construction documents.
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Glazing Factor: The ratio of interior illuminance at a given point on a given plane (usually the work plane) to the exterior illuminance under known overcast sky conditions. LEED uses a simplified approach for its credit compliance calculations. The variables used to determine the daylight factor include the floor area, window area, window geometry, visible transmittance (Tvis) and window height.
gpf: Gallons per flush (gpf) is a measure of water use of toilets and urinals.
gph: Gallons per hour (gph) is a measurement of the flow rate of water heaters.
gpm: Gallons per minute (gpm) is a measurement of the flow rate of water faucets and fixtures.
Graywater: 1. Defined by the Uniform Plumbing Code (UPC) in its Appendix G, titled"Gray water Systems for Single-Family Dwellings,"as"untreated household wastewater which has not come into contact with toilet waste. Grey water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs. It shall not include wastewater from kitchen sinks or dishwashers."2. The International Plumbing Code (IPC) defines graywater in its Appendix C, titled"Graywater Recycling Systems,"as"wastewater discharged from lavatories, bathtubs, showers, clothes washers, and laundry sinks."Some states and local authorities allow kitchen sink wastewater to be included in graywater. Other differences with the UPC and IPC definitions can probably be found in state and local codes. Project teams should comply with the graywater definitions as established by the authority having jurisdiction in their areas.
Green Seal: A multiple-attribute third-party certification and labeling program established in 1992 which covers a wide range of products with sector-specific requirements.
Green-e: Green-e is a program established by the Center for Resource Solutions to both promote green electricity products and provide consumers with a rigorous and nationally recognized method to identify those products.
Greenguard Children & Schools: A third-party indoor air quality certification and label established in 2005 that meets California Section 01350 requirements. Don’t confuse it with the less stringent Greenguard Indoor Air Quality certification.
Greenguard Indoor Air Quality: A third-party certification and label established in 2000. The more stringent Greenguard Children and Schools certification meets California Section 01350.
Gross Energy Intensity: Total consumption of a particular energy source(s) or fuel(s) by a group of buildings, divided by the total floorspace of those buildings, including buildings and floorspace where the energy source or fuel is not used, i.e., the ratio of consumption to gross floorspace.
gross floor area: Gross floor area (based on ASHRAE definition) is the sum of the floor areas of the spaces within the building, including basements, mezzanine and intermediate‐floored tiers, and penthouses wi th headroom height of 7.5 ft (2.2 meters) or greater. Measurements m ust be taken from the exterior 39 faces of exterior walls OR from the centerline of walls separating buildings, OR (for LEED CI certifying spaces) from the centerline of walls separating spaces.Excludes non‐en closed (or non‐enclosable) roofed‐over areas such as exterior covered walkways, porches, terraces or steps, roof overhangs, and similar features. Excludes air shafts, pipe trenches, and chimneys. Excludes floor area dedicated to the parking and circulation of motor vehicles. (Note that while excluded features may not be part of the gross floor area, and therefore technically not a part of the LEED project building, they may still be required to be a part of the overall LEED project and subject to MPRs, prerequisites, and credits.)
Gross Floorspace: Total floorspace of a group of buildings, regardless of which end uses are present or which energy sources or fuels are used within the buildings.
Gross Square Footage: Sum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but excluding covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features.
Ground Source Heat Pump: A type of heat pump that uses the natural heat storage ability of the earth and/or the groundwater to heat and/or cool a building. The earth has the ability to absorb and store heat energy from the sun. To use that stored energy, heat is extracted from the earth through a liquid medium (groundwater or an anti-freeze solution) and is pumped to the heat pump or heat exchanger. There, the heat is used to heat the building. In the summer, the process is reversed and indoor heat is extracted from the building and transferred to the earth through the liquid. The geothermal heat pump is more efficient than an air-source heat pump. Also referred to as a"closed-loop"system.
GWP: Global Warming Potential is a measure of how much heat is trapped by a given mass of gas, contributing to global warming, compared with the same mass of carbon dioxide. Carbon dioxide has a GWP value of 1.
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Halogen Light Bulb: A type of incandescent light bulb that lasts much longer and is more efficient than a standard incandescent light bulb. The light bulb uses a halogen gas, usually iodine or bromine, that causes the evaporating tungsten to be redeposited on the filament, thus prolonging its life. Halogen lamps produce a brighter, whiter light than standard incandescent. They are especially suited to recessed or"canned fixtures,"track lights, and outdoor lights.
Halons: Halons are substances, used in fire-suppression systems and fire extinguishers, that deplete the stratospheric ozone layer.
HCFCs: Hydrochlorofluorocarbons (HCFCs) are refrigerants that cause significantly less depletion of the stratospheric ozone layer than chlorofluorocarbons.
Heat Island Effect: Heat island effect refers to the absorption of heat by hardscapes, such as dark, nonreflective pavement and buildings, and its radiation to surrounding areas. Particularly in urban areas, other sources may include vehicle exhaust, air-conditioners, and street equipment; reduced airflow from tall buildings and narrow streets exacerbates the effect.
Heat Pump: A type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source.
Heat-recovery ventilator: A ventilation system that transmits heat from exhaust air to incoming fresh air.
Heating Degree-Days: A measure of how cold a location was over a period of time, relative to a base temperature. In CBECS, the base temperature used is 65 degrees Fahrenheit, and the period of time is one year. The heating degree-day is the difference between that day's average temperature and 65 degrees if the daily average is less than 65; it is zero if the daily average temperature is greater than or equal to 65. Heating degree-days for a year are the sum of the daily heating degree-days for days that year.
HEPA filters: Filters that remove virtually all (99.97%) 0.3-micron particles.
HERS Index: A scoring system established by the Residential Energy Services Network (RESNET) in which a home built to the specifications of the HERS Reference Home (based on the 2006 International Energy Conservation Code) scores a HERS Index of 100, while a net zero energy home scores a HERS Index of 0. The lower a home's HERS Index, the more energy efficient it is in comparison to the HERS Reference Home.
Hertz: Hertz (Hz) is the unit used to describe the frequency of vibrations (cycles) per second; 1 Hz equals 1 cycle per second.
HET: High Efficiency Toilet. A toilet that uses no more than 1.28 gallons per flush (20% less than the federal standard of 1.6 gallons per flush).
High-Efficiency Particulate Air: HEPA filters remove virtually all (99.97%) 0.3-micron particles.
Horizontal Footcandles: Horizontal footcandles occur on a horizontal surface. They can be added together arithmetically when more than 1 source provides light to the same surface.
Horizontal View: The approach used to confirm that the direct line of sight to perimeter vision glazing remains available from a seated position. It uses section drawings that include the installed furniture to make the determination.
hospitality industry: The hospitality industry consists of companies within the food services, accommodations, recreation, and entertainment sectors.
Humid Watershed: Watershed that receives at least 40 inches of rainfall each year.
Hydrofluorocarbons: Hydrofluorocarbons (HFCs) are refrigerants that do not deplete the stratospheric ozone layer but may have high global warming potential. HFCs are not considered environmentally benign.
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IAQ: Indoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors.
IECC: International Energy Conservation Code
IFMA: International Facility Management Association
Impervious Surfaces: Surfaces that promote runoff of precipitation volumes instead of infiltration into the subsurface. The imperviousness or degree of runoff potential can be estimated for different surface materials.
Imperviousness: Resistance to penetration by a liquid and is calculated as the percentage of area covered by a paving system that does not allow moisture to soak into the ground.
Individual occupant spaces: In individual occupant spaces, occupants perform distinct tasks from one another. Such spaces may be contained within multi-occupant spaces and should be treated separately where possible. Individual occupant spaces may be regularly or non-regularly occupied spaces.
Indoor Advantage Gold™: A third-party indoor air quality certification that meets California Section 01350. It includes residential products via the 2010 Section 01350 residential protocol.
Indoor Advantage™: A third-party indoor air quality certification established in 2005 for low emitting furniture products. The more stringent Indoor Advantage Gold meets California Section 01350.
Integrated Design: Building or interior design in which different components, such as the building envelope, window placement and glazings, mechanical systems, furniture, and surface finishes are considered as part of building design, especially to achieve goals related to sustainability.
Integrated Pest Management: Integrated pest management (IPM) is the coordinated use of knowledge about pests, the environment, and pest prevention and control methods to minimize pest infestation and damage by the most economical means while minimizing hazards to people, property, and the environment.
Interior Lighting Power Allowance: Interior lighting power allowance is the maximum lighting power (in watts) allowed for the interior of a building.
Interior Non-Structural Components Reuse: Interior nonstructural components reuse is determined by dividing the area of retained components by the larger of (1) the area of the prior condition or (2) the area of the completed design.
IPC: International Plumbing Code
IPMVP: The International Performance Measurement and Verification Protocol (IPMVP) provides best-practice protocol for measurement and verification of new construction. This standard is referenced in LEED's measurement and verification credits.
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KL: The landscape coefficient (KL) is a constant used to calculate the evapotranspiration rate. It takes into account the species factor, density factor, and microclimate factor of the area.
kWh: A kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu.
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Landscape Area: The landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios.
Leakage rate: The speed at which an appliance loses refrigerant, measured between refrigerant charges or over 12 months, whichever is shorter. The leakage rate is expressed in terms of the percentage of the appliance's full charge that would be lost over a 12-month period if the rate stabilized. (EPA Clean Air Act, Title VI, Rule 608).
Learning spaces: Core learning spaces are spaces for educational activities where the primary functions are teaching and learning and where good speech communication is critical to a student's academic achievement. These spaces include, but are not limited to, classrooms, enclosed or open plan), instructional pods or activity areas, group instruction rooms, conference rooms, libraries, offices, speech clinics, offices used for educational purposes and music rooms for instruction, practice and performance.
LED: Light-emitting diodes, or LEDs, use semiconductors to produce light, giving them more in common with computer chips than with conventional incandescent lighting.
Legionella pneumophila: Legionella pneumophila is a waterborne bacterium that causes Legionnaire's disease. It grows in slow-moving or still warm water and can be found in plumbing, showerheads, and water storage tanks. Outbreaks of Legionella pneumonia have been attributed to evaporative condensers and cooling towers.
Life Cycle Analysis: An evaluation of the environmental effects of a product or activity holistically, by analyzing the entire life cycle of a particular material, process, product, technology, service, or activity.
Life Cycle Inventory: An accounting of the energy and waste associated with the creation of a new product through use and disposal.
Life-Cycle assessment: 1. Life-cycle assessment is an analysis of the environmental aspects and potential impacts associated with a product, process, or service.2. The practice of quantifying and characterizing all the resource and pollution flows associated with a process or product, for the purpose of documenting its environmental impact. It is defined by the International Organization of Standardization (ISO) as"a compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life-cycle."
Life-Cycle Cost: Economic cost of a product or building over its expected life, including first cost, operating cost, and, when appropriate, cost of disposal or demolition.
lodging: Lodging are facilities that provide overnight accommodations to customers or guests, including hotels, motels, inns and resorts.
Long Life, Loose Fit: A general approach to design that allows buildings and interiors to adapt to future uses. Strategies include specifying durable materials as well as divisions of interior space that can be easily adjusted.
Low-E: Low-E or Low-Emissivity Coating: Very thin metallic coating on glass or plastic window glazing that reduces heat loss and heat gain through the window; the coating emits less radiant energy (heat radiation), which makes it, in effect, reflective to that heat. In that way it boosts a window's R-value and reduces its U-factor.
Low-Emitting Vehicles: Low-emitting vehicles are classified as zero-emission vehicles (ZEVs) by the California Air Resources Board.
LPD: Lighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space.
lpw: Lumens per watt (lpw) measures the efficacy of lighting, or how much light (measured in lumens) is produced per unit of power (measured in watts).
Lumen: 1. A lumen is a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of 1 candle intensity.2. A measurement of light output.
Luminaire: An entire LED light source including the LED chip(s) or light engine, heat management system, and electronics.
Lux: Measurement of lumens per square meter.
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MDF: Medium-density fiberboard (MDF): Panel product used in cabinets and furniture; generally made from wood fiber glued together with binder; similar to particleboard, but with finer texture, offering more precise finishing. Most MDF is made with formaldehyde-emitting urea-formaldehyde binder.
MDI: Methyl Diisocyanate non-formaldehyde binder used in some medium-density fiberboard and particleboard products, including straw-based particleboard.
MEF: Modified Energy Factor measures total energy consumption per cycle, including the dryer energy used to remove moisture in washed items. The higher the MEF, the more efficient the washer is in the entire laundry cycle.
MERV: Minimum efficiency reporting value.
Microclimate Factor: Microclimate factor (kmc) is a constant used in calculating the landscape coefficient. It adjusts the evapotranspiration rate to reflect the climate of the immediate area.
Movable furniture and partitions: Movable furniture and partitions are those that can be moved to provide access to the view by the user without the need for tools or assistance from special trades and facilities management.
MPI's X-Green Performance Standard: Master Painters Institute's X-Green Green Performance Standard indicates a product has met performance testing requirements along with third-party testing of low emissions according to California Section 01350.
MSDS: 1. Material safety data sheets (MSDS) are detailed, written instructions documenting a method to achieve uniformity of performance.2. A report that manufacturers of most products are required to make available to installers and purchasers, informing them of product information on chemicals, chemical compounds, and chemical mixtures, the existence of potentially hazardous ingredients, and providing instructions for the safe handling, storage, and disposal of products
Multi-Occupant Spaces: Conference rooms, classrooms and other indoor spaces used as a place of congregation for presentations, trainings, etc. Individuals using these spaces share the lighting and temperature controls and they should have, at a minimum, a separate zone with accessible thermostat and an air-flow control. Group multi-occupant spaces do not include open office plans that contain individual workstations.
Multiple Chemical Sensitivity: A health condition in which exposure to a wide range of substances, at levels that would not be noticed by the general population, causes medical problems.
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Native Vegetation: Plants indigenous to a locality (native) and adapted to the local climate; they require limited irrigation following planting, do not require active maintenance such as mowing, and provide habitat value.
Net Project Material Value: Net project material value includes the construction material value and the CSI Division 12 (Furniture and Furnishings) material value, the lesser of material values for mechanical and electric components, and the salvage value identified in the MR credits.
NOAA Division: One of the 356 weather divisions designated by the National Oceanic and Atmospheric Administration (NOAA) that encompass the 50 contiguous United States and the District of Columbia. These divisions usually follow county borders to encompass counties with similar weather conditions. However, the NOAA division does not follow county borders when weather conditions vary considerably within a county, as is likely to be the case when a county borders the ocean or contains high mountains. A State contains an average of seven NOAA divisions; a NOAA division contains an average of nine counties.
Non-densely occupied spaces: Non-densely occupied spaces are areas with a design occupant density of less than 25 people per 1,000 square feet (40 square feet or more per person)."
Nonoccupied spaces: Nonoccupied spaces are defined as spaces designed for equipment and machinery or storage with no human occupancy except for maintenance, repairs, and equipment retrieval.
Nonpoint Source Pollution: Water pollution from contaminants that are carried by stormwater runoff into water bodies such as streams and lakes.
Nonpotable Water: Nonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents.
Nonregularly Occupied Space: Non-regularly occupied spaces are spaces that occupants pass through, or spaces used in pursuit of focused activities for less than one hour per person per day (on average).
NPDES: The National Pollutant Discharge Elimination System (NPDES) is a permit program that controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters.
NPV: Net present value: The total discounted value of all cash inflows and outflows from a project or investment, or a formula used in assessing the value of an investment, calculated by taking the present value of an investment's future net cash flows and subtracting the initial investment.
NRC: Noise reduction coefficient (NRC) is the arithmetic average of absorption coefficients at 250, 500, 1,000, and 2,000 Hz for a material. The NRC is often published by manufacturers in product specifications, particularly for acoustical ceiling tiles and acoustical wall panels.
NSF-140: An ANSI-approved multiple-attribute third-party standard for carpet, to which manufacturers have their product third-party certified. This standard has four performance tiers with Platinum the highest achievement level.
NSF/ANSI 332: NSF-332 is an ANSI-approved multiple-attribute third-party standard for resilient flooring emissions established in 2010. NSF-332 has four performance tiers with Platinum the highest achievement level.
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Occasional Furniture: Occasional furniture is located in lobbies and in conference rooms.
Occupied spaces: Occupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space.
Octave Band: A section of a frequency scale in which the upper band-edge frequency (f2) is twice the lower band-edge frequency (f1). Each octave band is identified by its center frequency.
ODP: Ozone Depletion Potential is a measure of the relative potency of different chemicals in terms of ozone destruction. ODPs are generally measured relative to the refrigerant gas, CFC-11, which is defined to have an ODP of 1.0. Use of high-ODP gasses has been largely phased out.
Off-Hours Equipment Reduction: A method of conserving energy by changing the temperature setting or reducing the use of heating, cooling, lighting, or office equipment either manually or automatically when the building is closed. In 2003, for buildings open 24 hours a day, this question also included whether heating or cooling was reduced during any periods over a normal 24 hour day.
once-through cooling: A once-through (single pass) cooling system is one which water from any source is used to transfer heat from equipment or processes and then discharged.
Ongoing Consumables: Ongoing consumables have a low cost per unit and are regularly used and replaced in the course of business. Examples include paper, toner cartridges, binders, batteries, and desk accessories.
Open Space Area: Open space area is usually defined by local zoning requirements. If local zoning requirements do not clearly define open space, it is defined for the purposes of LEED calculations as the property area minus the development footprint; it must be vegetated and pervious, with exceptions only as noted in the credit requirements section. Only ground areas are calculated as open space. For projects located in urban areas that earn a Development Density and Community Connectivity credit, open space also includes nonvehicular, pedestrian-oriented hardscape spaces.
OPR: Owner's project requirements (OPR) is a written document that details the ideas, concepts, and criteria that are determined by the owner to be important to the success of the project.
OSB: Oriented-strand board (OSB). Consists of wood or plant particles or fibers bonded by a synthetic resin or binder. Examples include particleboard, medium-density fiberboard (MDF), plywood, wheatboard, oriented-strand board, and strawboard.
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Partially Shielded: In a partially shielded exterior light fixture, the lower edge of the shield is at or below the centerline of the lamp, to minimize light emitted above the horizontal plane.
Percent Lit When Closed: The percentage of a building's square footage that is lit electrically during all hours other than the usual operating hours.
Percent Lit When Open: The percentage of a building's square footage that is lit electrically during usual operating hours.
PFOA: A perfluorochemical (PFC) that is used to manufacture compounds used in Teflon and formerly used in Scotchguard products, as well as many other applications. A likely carcinogen, PFOA does not appear to break down in the environment, and has been found in human and animal tissue around the planet.
Phenol Formaldehyde: Phenol formaldehyde, which off-gasses only at high temperature, is used for exterior products, although many of these products are suitable for interior applications.
Picogram: A picogram is 1 trillionth of a gram.
Picograms Per Lumen-Hour: Picograms per lumen-hour is a measure of the amount of mercury in a lamp per unit of light delivered over its useful life.
Plasticizer: Chemical compound added to a material to make it more flexible or softer. The most common plasticizers used in PVC (vinyl) products such as flooring and wallcoverings are various phthalates that are suspected of causing cancer and/or endocrine disruptions.
Post-Consumer: Waste material generated by households or by commercial, industrial and institutional facilities in their role as end-users of the product, which can no longer be used for its intended purpose. This includes returns of materials from the distribution chain (source: ISO 14021). Examples of this category include construction and demolition debris, materials collected through curbside and drop-off recycling programs, broken pallets (if from a pallet refurbishing company, not a pallet-making company), discarded products (e.g., furniture, cabinetry and decking) and urban maintenance waste (e.g., leaves, grass clippings, tree trimmings, etc.).
Post-Industrial: Refers to material diverted from the waste stream during a manufacturing process. Excluded from this category is reutilization of materials such as scrap that are generated in a process and capable of being reclaimed within the same process. Generally synonymous with"pre-consumer."
Potable Water: Potable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems.
PPB: Parts per billion.
PPM: Parts per million.
Precautionary approach: The precautionary approach is a stance on product and material selection based on use of the precautionary principle, which suggests that we should avoid using questionable chemicals and materials until science has proven them safe. In this approach, if there are reasonable questions about a material's safety relative to environmental or human health, it should be avoided when possible.
Predevelopment: Predevelopment refers to before the LEED project was initiated, but not necessarily before any development or disturbance took place. Predevelopment conditions describe conditions on the date the developer acquired rights to a majority of the buildable land on the project site through purchase or option to purchase.
Preferred Parking: Preferred parking, available to particular users, includes designated spaces close to the building (aside from designated handicapped spots), designated covered spaces, discounted parking passes, and guaranteed passes in a lottery system.
Present Value: The current value of one or more future cash payments, discounted by an appropriate interest rate.
Previously developed: Previously developed sites are those altered by paving, construction, and/or land use that would typically have required regulatory permitting to have been initiated (alterations may exist now or in the past). Previously developed land includes a platted lot on which a building was constructed if the lot is no more than 1 acre; previous development on lots larger than 1 acre is defined as the development footprint and land alterations associated with the footprint. Land that is not previously developed and altered landscapes resulting from current or historical clearing or filling, agricultural or forestry use, or preserved natural area use are considered undeveloped land. The date of previous development permit issuance constitutes the date of previous development, but permit issuance in itself does not constitute previous development."
private use: Private use applies to plumbing fixtures in residences, apartments, and dormitories, to private (non-public) bathrooms in transient lodging facilities (hotels and motels), and to private bathrooms in hospitals and nursing facilities.
Process Water: Process water is used for industrial processes and building systems such as cooling towers, boilers, and chillers. It can also refer to water used in operational processes, such as dishwashing, clothes washing, and ice making.
psi: Pounds per square inch (psi) measures the water pressure at a water fixture. Water efficiency measurements assume a certain pressure, usually 80 psi.
PSU: Primary Sampling Unit: A sampling unit selected at the first stage in a multistage area probability sample. A PSU typically consists of one to several contiguous countiesfor example, an MSA (metropolitan statistical area) with surrounding suburban counties.
public use: Public or public use applies to all buildings, structures, or uses that are not defined as private or private use.
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QC Plan: Quality Control Plan: Portfolio-level or schema-levelThe general methods the volume review customer uses to ensure that the sustainable intent for its LEED projects becomes reality, ensuring that LEED requirements have been incorporated into its standard building processes. This level of the QC Plan describes generic organization-level checking and verification processes used for any building design, construction, or operational settings and across multiple types of building project issues and technical goals. Credit-level Builds on and supplements the generic QC Plan by providing detailed, credit-specific methods tailored to and suitable foreach specific type of building process (i.e., plan review, commissioning, field inspections, periodic preventive maintenance, review of automation trend logs, etc.). Describes all aspects of the customer's internal verification processes: who, what, when, where, how, to what extent. This level of QC Plan detail is required for all prototyped or streamlined credits (except for some streamlined approaches in the LEED-EB setting).
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Rainforest Alliance Certification: Rainforest Alliance certification is awarded to farms that protect wildlife by planting trees, control erosion, limit agrochemicals, protect native vegetation, hire local workers, and pay fair wages.
Rapidly Renewable: Term describing a natural material that is grown and harvested on a relatively short-rotation cycle (defined by the LEED rating system to be ten years or less).
Rated Power: Rated power is the nameplate power on a piece of equipment. It represents the capacity of the unit and is the maximum that it will draw.
Rational Method: A formula that can be used for calculating stormwater flow rates. Q = CIA, where C represents a coefficient for physical drainage area, I is the rainfall intensity, and A is area. The method is suitable for watersheds smaller than 300 acres in size.
RCRA: The Resource Conservation and Recovery Act (RCRA) addresses active and future facilities and was enacted in 1976 to give EPA authority to control hazardous wastes from cradle to grave, including generation, transportation, treatment, storage, and disposal. Some nonhazardous wastes are also covered under RCRA.
REC: A Renewable Energy Certificate (REC) is a certificate representing proof that a given unit of electricity was generated from a renewable energy source such as solar or wind. These certificates are able to be sold, traded, or bartered as environmental commodities, where an electricity consumer can buy the renewable energy attributes of electricty to support renewable energy, even if they are consuming generic grid-supplied electricity that may be supplied by nonrenewable sources.
Regularly occupied spaces: Regularly occupied spaces are areas where one or more individuals normally spend time (more than one hour per person per day on average) seated or standing as they work, study, or perform other focused activities inside a building.
Reverberation: Reverberation is an acoustical phenomenon that occurs when sound persists in an enclosed space because of its repeated reflection or scattering on the enclosing surfaces or objects within the space. (ANSI S12.602002)
RoHS Compliant: Manufacturers may self-declare compliance or have a product third-party certified as compliant with the European Union's Restriction of Hazardous Substances (RoHS) Directive. While most relevant to electronics, other products may claim RoHS compliance as an indication of reduced toxicity.
roof area: Roof area is the area of the uppermost surface of the building which covers enclosed Gross Floor Area, as measured when projected onto a flat, horizontal surface (i.e. as seen in Roof Plan view).‘Roofs’, or portions of roofs, covering unenclosed areas (e.g. roofs over porches and open covered parking structures) are not included in the areas used to evaluate compliance with SSc7.2, though they may be applicable to SSc7.1.
RT: Reverberation time (RT) is a measure of the amount of reverberation in a space and equal to the time required for the level of a steady sound to decay by 60 dB after the sound has stopped. The decay rate depends on the amount of sound absorption in a room, the room geometry, and the frequency of the sound. RT is expressed in seconds. (ANSI S12.602002)
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SBS: Sick building syndrome (SBS): 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. A pattern of health complaints related to poor indoor air quality in a specific building, but without a known cause or a definite, diagnosable pattern of symptoms.
SCS Environmentally Preferable Products: EPP is a multiple-attribute third-party sustainability certification based on Scientific Certification System's unique Life Cycle Analysis protocol.
SCS Recycled and Material Content: Scientific Certification System (SCS) provides third-party verification of manufacturer claims such as the percentage of recycled content in a product.
SCS Sustainable Choice: While originally defined more broadly, Sustainable Choice has become Scientific Certification System (SCS)'s branding for third-party certification of carpet to the NSF-140 standard.
Sealed Combustion: Combustion system for space heating or water heating in which outside combustion air is fed directly into the combustion chamber and flue gasses are exhausted directly outside.
sealers: Sealers are coatings applied to either block materials from penetrating into or leaching out of a substrate, to prevent subsequent coatings from being absorbed by the substrate, or to prevent harm to subsequent coatings by materials in the substrate.
Semiarid Watershed: Watershed that receives between 20 and 40 inches of rainfall per year.
Setpoints: Setpoints are normal operating ranges for building systems and indoor environmental quality. When the building systems are outside of their normal operating range, action is taken by the building operator or automation system.
SHGC: Solar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.
Shielding: Shielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow.
Sky Glow: Sky glow is caused by stray light from unshielded light sources and light reflecting off surfaces that then enter the atmosphere and illuminate and reflect off dust, debris, and water vapor. Sky glow can substantially limit observation of the night sky, compromise astronomical research, and adversely affect nocturnal environments.
Smart Certified: The SMaRT Sustainable Product Standard version four is an ANSI-approved multiple-attribute third-party certification. SMaRT has four performance tiers, based on points achieved with Platinum the highest achievement level.
SOP: A standard operating procedure (SOP) manual can be used to document routine operations and maintenance practices, and to encourage use of standardized best practices.
Sound Absorption Coefficient: Sound absorption coefficient describes the ability of a material to absorb sound, expressed as a fraction of incident sound. The sound absorption coefficient is frequency-specific and ranges from 0.00 to 1.00. For example, a material may have an absorption coefficient of 0.50 at 250 Hz, and 0.80 at 1,000 Hz. This indicates that the material absorbs 50% of incident sound at 250 Hz, and 80% of incident sound at 1,000 Hz. The arithmetic average of absorption coefficients at midfrequencies is the noise reduction coefficient.
Source Energy: Source energy is the total amount of raw fuel required to operate a building; it incorporates all transmission, delivery, and production losses for a complete assessment of a building's energy use.
Species Factor: Species factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species.
Specular Reflectors: The mirror-like backing of a fluorescent lighting fixture designed specifically to reflect light into the room. The materials and shape of the reflector are designed to reduce absorption of light within the fixture, while delivering light in the desired angular pattern. The most common materials used are silver (highest reflectivity) and aluminum (lowest cost).
SRI: The solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100.
Standard Error: A measure of the precision of an estimate, equal to the square root of the variance.
STC: Sound transmission class (STC) is a single-number rating for the acoustic attenuation of airborne sound passing through a partition or other building element, such as a wall, roof, or door, as measured in an acoustical testing laboratory according to accepted industry practice. A higher STC rating provides more sound attenuation through a partition. (ANSI S12.602002)
Submeter: Submetering is used to determine the proportion of energy or water use within a building attributable to specific end uses such as tenant spaces, or subsystems such as the heating component of an HVAC system.
Submetering: Submetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system).
Sustainable Forestry Initiative (SFI): Thorough system, but less prescriptive than FSC. Historically close to the forest industry.
Systems Furniture: Systems furniture includes panel-based workstations comprising modular interconnecting panels, hang-on components, and drawer and filing components or a free-standing grouping of furniture items designed to work in concert.
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TAG: LEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system.
Tertiary Treatment: Tertiary treatment is the highest form of wastewater treatment and includes removal of organics, solids, and nutrients as well as biological or chemical polishing, generally to effluent limits of 10 mg/L biological oxygen demand (BOD) 5 and 10 mg/L total suspended solids (TSS).
Tipping Fees: Tipping fees are charged by a landfill for disposal of waste, typically quoted per ton.
Toe of the Slope: Where there is a distinct break between a 40% slope and lesser slopes.
TP: Total phosphorus (TP) consists of organically bound phosphates, polyphosphates, and orthophosphates in stormwater, the majority of which originates from fertilizer application. Chemical precipitation is the typical removal mechanism for phosphorus.
TSS: Total suspended solids (TSS) are particles that are too small or light to be removed from stormwater via gravity settling. Suspended solid concentrations are typically removed via filtration.
Tvis: Visible light transmittance (VLT) (Tvis) is the ratio of total transmitted light to total incident light (i.e., the amount of visible spectrum, 380780 nanometers of light passing through a glazing surface divided by the amount of light striking the glazing surface). The higher the Tvis value, the more incident light passes through the glazing.
TVOC: The sum or total of all volatile organic compounds (VOCs) released from a product or measured in a space under certain defined conditions.
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Universal Notification: Universal notification means notifying building occupants not less than 72 hours before a pesticide is applied in a building or on surrounding grounds under normal conditions, and within 24 hours after application of a pesticide in emergency conditions. Use of a least toxic pesticide or self-contained nonrodent bait does not require universal notification; all other pesticide applications do.
UPC: Uniform Plumbing Code
UPS: An uninterrupible power supply, or UPS, provides usually short-term emergency power to computer or other systems in case of outages.
Upstream Equipment: Upstream equipment consists of all heating or cooling systems, equipment, and controls that are associated with a district energy system but are not part of the project building's thermal connection or do not interface with the district energy system. It includes the central energy plant and all transmission and distribution equipment associated with transporting the thermal energy to the project building and site.
Urban Heat Island: A densely populated area in which pavement and buildings absorb, store, and release solar energy, making the vicinity warmer than it would be if the pavement and buildings were not present.
Urea Formaldehyde: Urea formaldehyde is a combination of urea and formaldehyde that is used in some glues and may emit formaldehyde at room temperature.
UV: Ultraviolet light, or UV, is a type of radiation from sunlight and other light sources that is considered a hazard for skin health.
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VAV: Variable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas.
Vertical Footcandles: Vertical footcandles occur on a vertical surface. They can be added together arithmetically when more than 1 source provides light to the same surface.
VFD: A variable frequency drive (VFD) is a device for for controlling the speed of a motor by controlling the frequency of the electrical power supplied to it. VFDs may be used to improve the efficiency of mechanical systems as well as comfort, because they use only as much power as needed, and can be adjusted continuously.
VMT: Vehicle Miles Traveled (VMT): The number of miles traveled by motor vehicles in a specified period of time, such as a day or a year, by a number of motorists in absolute or per capita terms.
VOCs: 1. Volatile organic compounds (VOCs) are carbon compounds that participate in atmospheric photochemical reactions (excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides and carbonates, and ammonium carbonate). The compounds vaporize (become a gas) at normal room temperatures.2. A molecule containing one or more carbon atoms that tends to evaporate (volatilize) into the air at typical ambient conditions. Some legal definitions of VOCs are restricted to those that react with sunlight to generate smog. Some VOCs are carcinogens, suspected carcinogens, or known irritants at typical levels.
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WF: Water Factor is the number of gallons per cycle per cubic foot that the clothes washer uses. The lower the water factor, the more efficient the washer.
WFR: Window-to-floor ratio (WFR) is the total area of the window (measured vertically from 30 inches above the finished floor to the top of the glass, multiplied by the width of the glass) divided by the floor area.
Woonerf: A Dutch word that means"street for living."In practice, it is common space shared by pedestrians, bicyclists, and low-speed motor vehicles. They are usually streets raised to the same grade as curbs and sidewalks. Vehicles are slowed by placing trees, planters, parking areas, and other obstacles in the street, so that motorists travel at walking speed.
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Xeriscaping: Xeriscaping is a landscaping method that makes routine irrigation unnecessary. It uses drought-adaptable and low-water plants as well as soil amendments such as compost and mulches to reduce evaporation.
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ZEV: Zero-emission vehicles.

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