About the Program

Compliance Tools

Training/Education

Implementation Tools

Technical Support/FAQs

Building Energy Codes Glossary

This listing contains terms and acronyms that are used throughout the BECP website and compliance tools.

A

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Above-grade Walls: Those walls (Section 802.2.1) on the exterior of the building and completely above grade or the above grade portion of a basement or first-story wall that is more than 15 percent above grade.
Addition: An extension or increase in the height, conditioned floor area, or conditioned volume of a building. The code applies to additions of existing buildings.

Additions include new construction, such as a conditioned bedroom or sun space. Additions also include existing spaces converted from unconditioned to conditioned spaces (converting an existing porch to a conditioned sunroom).
Air Economizer Systems: Ducting arrangements and automatic control systems that allow a cooling supply fan system to supply outdoor (outside) air to reduce or eliminate the need for mechanical refrigeration during mild or cold weather.
Alteration: Any construction renovation, or change in a mechanical system that involves an extension, addition, or change to the arrangement, type, or purpose of the original installation.
AFUE: Annual fuel utilization efficiency; combustion heating equipment efficiency is expressed in terms of AFUE. New equipment typically ranges from about 78- to 96-percent AFUE. Higher AFUE ratings indicate more efficient equipment.
ASHRAE/IES Standard 90.1-1989: The American Society of Heating, Refrigerating and Air-Conditioning Engineers/Illumination Engineering Society Standard 90.1-1989.
AAMA: Architectural Aluminum Manufacturers Association
ARI: Air-conditioning and Refrigeration Institute
Automatic Time-Switch Controls: Controls that automatically switch lights or equipment on and off.
Automatically Operated Control Damper: A damper which automatically opens and closes.

B

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Ballast: A device used to operate fluorescent and HID lamps. The ballast provides the necessary starting voltage, while limiting and regulating the lamp current during operation.
Basement Wall: Basement walls that enclose conditioned spaces are part of the building envelope. Basement wall refers to the opaque portion of the wall (excluding windows and doors). To be considered a basement wall, at least 50% of the wall's total wall area (including openings) must be below grade. Treat walls on each side of the basement individually when determining if they are above grade or basement walls. For any individual wall less than 50% below grade, include the entire opaque wall area of that individual wall as part of the above-grade walls.
Below-Grade Walls: Basement or first story walls (Section 802.2.8) associated with the exterior of the building that are at least 85 percent below grade.
BOCA: Building Officials and Code Administrators International, Inc.
Boiler: A pressurized system in which water is vaporized to steam by heat transferred from a source of higher temperature, usually the products of combustion from burning fuels. Steam thus generated may be used directly as a heating medium, or as the working fluid in a prime mover to convert thermal energy to mechanical work, which in turn may be converted to electrical energy.
Btu: British thermal unit, which is the quantity of heat required to raise the temperature of 1 pound (0.454 kg) of water 1°F
(0.56°C), (1 Btu = 1,055 J).
Building Envelope: All components of a building that enclose conditioned space. Building envelope components separate conditioned spaces from unconditioned spaces or from outside air (see conditioned space). For example, walls and doors between an unheated garage and a living area are part of the building envelope; walls separating an unheated garage from the outside are not. Although floors of conditioned basements and conditioned crawl spaces are technically part of the building envelope, the code does not specify insulation requirements for these components and they can be ignored.

C

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

CABO

The Council of American Building Officials

Cavity Insulation

Insulation installed between structural members.

Ceiling

The ceiling requirements apply to portions of the roof and/or ceiling through which heat flows. Ceiling components include the interior surface of flat ceilings below attics, the interior surface of cathedral or vaulted ceilings, skylights, or vaulted ceilings, skylights and sloped building assemblies less than 60° from horizontal, but excluding skylight shafts.

Circulation Pumps

Pumps that are used to keep hot water circulating through the distribution system.

Circulating Water Heater

Hot water continuously circulates through the distribution system.

Coefficient of Performance (COP)

Cooling: The ratio of the rate of heat removal to the rate of energy input in consistent units, for a complete cooling system or factory-assembled equipment, as tested under a nationally recognized standard or designated operating conditions.
Heat Pump-Heating: The ratio of the rate of heat delivered to the rate of energy input, in consistent units, for a complete heat pump system under designated operating conditions. Supplemental heat shall not be considered when checking compliance with the heat pump equipment (COPs listed in the tables in Sections 503 and 803).

Commercial Building

Includes but is not limited to occupancies for assembly, business, education, institutions, merchants, and storage.

Compact Fluorescents

Small fluorescent lamps that are often used as an alternative to incandescent lighting. The lamp life is about 10 times longer than incandescent lamps and is 3-4 times more efficacious.

Concrete Masonry Unit Walls

Concrete masonry unit walls may be insulated by filling the empty core with perlite, vermiculite, or some other insulative material. In some cases, even with filled cores, these wall types require additional insulation.

Condensing Unit

A specific refrigerating machine combination for a given refrigerant, consisting of one or more power-driven compressors, condensers, liquid receivers (when required), and the regularly furnished accessories.

Conditioned Floor Area

The horizontal projection of that portion of interior space which is contained within exterior walls and which is conditioned directly or indirectly by an energy-using system.

Conditioned Space

A space is conditioned if heating and/or cooling is deliberately supplied to it or is indirectly supplied through uninsulated surfaces of water or heating equipment; uninsulated ducts; or uninsulated floors, ceilings, or walls between it and another conditioned space. For example, a basement is conditioned if:

it has registers or heating devices designed to supply heat, or
the basement ceiling is not insulated and the space above it is conditioned, or
the space contains uninsulated ducts or uninsulated surfaces of water heaters or space heating equipment.

Connected Lighting Load

The sum of all non-exempt interior lighting power, measured in watts.

Continuous Insulation

Insulation that runs continuously over structural members and is free of significant thermal bridging; such as rigid foam insulation above the ceiling deck.

Cooled Space

An enclosed space within a building that is cooled by a cooling system whose capacity (a) exceeds 6 Btu per hour per square foot or (b) is capable of maintaining a space dry-bulb temperature of 90°F or less at design cooling conditions.

Cooling Degree Days

A unit, based on temperature difference and time, used in estimating cooling energy consumption and specifying nominal cooling load of a building in summer. For any one day, when the mean temperature is more than 65°F (18°C), there are as many degree days as there are degrees Fahrenheit (Celsius) difference in temperature between the mean temperature for the day and 65°F (18°C). Annual cooling degree days (CDD) are the sum of the degree days over a calendar year.

COP

See Coefficient of Performance

Crawl Space

The REScheck crawl space wall insulation requirements are for the exterior walls of unventilated crawl spaces (i.e. not directly vented to the outside) below uninsulated floors. A crawl space wall component includes the opaque portion of a wall that encloses a crawl space and is partially or totally below grade, as measured from the sill to the top of the footing.

Crawl Space Wall

The opaque portion of a wall which encloses a crawl space and is partially or totally below grade.

D

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Deadband: The temperature range in which no heating or cooling is used.
Degree Day: See Heating Degree Days
Domestic Water Heating System: DHW systems may be circulating or non-circulating.
Door: Doors include all openable opaque assemblies located in exterior walls of the building envelope. Doors with glass can be treated as a single door assembly, in which case an aggregate U-factor (a U-factor that includes both the glass and the opaque area) must be used; OR the glass area of the door can be included with the other glazing and an opaque door U-factor can be used to determine compliance of the door.
Duct: A tube or conduit used for conveying air. The air passages of self-contained systems are not to be construed as air ducts.
Duct Furnace: A furnace normally installed in distribution ducts of air conditioning systems to supply warm air for heating and which depends on a blower not furnished as part of the duct furnace for air circulation.
Duct System: A continuous passageway for the transmission of air that, in addition to ducts, includes duct fittings, dampers, plenums, fans, and accessory air-handling equipment and appliances.
Dwelling Unit: A single housekeeping unit of one or more rooms providing complete, independent living facilities, including permanent provisions for living, sleeping, eating, cooking, and sanitation.

E

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Economizer

A ducting arrangement and automatic control system that allow a cooling supply fan system to supply outdoor air to reduce or eliminate the need for mechanical refrigeration during mild or cold weather.

Efficacy

A metric used to compare light output to energy consumption. Efficacy is measured in lumens per watt. Efficacy is similar to efficiency, but is expressed in dissimilar units. For example, if a 100-watt source produces 9000 lumens, then the efficacy is 90 lumens per watt.

Electronic High-Frequency Ballasts

Electronic ballasts improve fluorescent system efficacy by converting the standard 60 Hz input frequency to a higher frequency, usually 25,000 to 40,000 Hz. Lights operating on these frequencies produce about the same amount of light, while consuming up to 30% less power than a standard magnetic ballast.

Enclosed Space

A volume substantially surrounded by solid surfaces such as walls, floors, roofs, and openable devices such as doors and operable windows. Spaces not meeting these criteria for enclosure are considered to be exterior to the building for purposes of determining envelope requirements. For example, most parking garages do not qualify as enclosed space.

Envelope Components

The building assemblies that provide a barrier between conditioned space and unconditioned space. This includes the floors, walls, and ceiling/roof assemblies of the building.

EER

The energy efficiency ratio is the ratio of net equipment cooling capacity in Btu/h to total rate of electric input in watts under designated operating conditions. When consistent units are used, this ratio becomes equal to coefficient of performance.

Equipment Efficiency

The measure of equipment efficiency varies with equipment type.

Combustion heating equipment efficiency is expressed in terms of AFUE. New equipment typically ranges from about 78- to 96-percent AFUE.
Cooling efficiency for electric air conditioners and heat pumps is expressed in terms of SEER. New equipment ranges from 10 to about 16 SEER.
Heat pump heating is expressed in terms of HSPF. New equipment ranges from about 6.8 to 10.0 HSPF.

Higher AFUE, SEER, and HSPF ratings indicate more efficient equipment.

Exterior Wall

An above-grade wall enclosing conditioned space. Includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing a mansard roof, and basement walls with an average below grade-wall area that is less than 50 percent of the total opaque and non-opaque area of that enclosing side.

F

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Fan Coil: A fan-coil terminal is essentially a small air-handling unit which serves a single space without a ducted distribution system. One or more independent terminals are typically located in each room connected to a supply of hot and/or chilled water. At each terminal, a fan in the unit draws room air (sometimes mixed with outside air) through a filter and blows it across a coil of hot water or chilled water and back into the room.
Fenestration: The terms "fenestration", "window", and "glazing" are often used interchangeably. However, fenestration refers to the design and position of windows, doors and other structural openings in a building.
Floor: A horizontal exterior partition, or a horizontal demising partition, under conditioned space which separates conditioned space from unconditioned space.
Fluorescent Lamps: A light source consisting of a tube filled with argon, along with krypton or other inert gas. When electrical current is applied, the resulting arc emits ultraviolet radiation that excites the phosphors inside the lamp wall, causing them to radiate visible light.
Fuel-Fired Furnace: A self-contained, indirect-fired furnace that supplies heated air through ducts to spaces that require it.

G

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Glazing: Any translucent or transparent material in exterior openings of buildings, including windows, skylights, sliding doors, the glass area of opaque doors, and glass block.
Glazing Area: The area of a glazing assembly is the interior surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. The nominal area or rough opening is also acceptable for flat windows and doors.
Glazing U-Factor: Based on the interior-surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. Center-of-glass U-factors cannot be used.
Gross Wall Area: The gross wall area includes the opaque area of above-grade walls, the opaque area of any individual wall of a conditioned basement less than 50% below grade (including the below-grade portions), all windows and doors (including windows and doors of conditioned basements), and the peripheral edges of floors.
Gross Window Area: Includes the rough-opening area of the window, not just the transparent-glass area.

H

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Heat Pump: One or more factory-made assemblies which include an indoor conditioning coil, compressor(s) and outdoor coil or refrigerant-to-water heat exchanger, including means to provide both heating and cooling functions.
Heat Traps: Devices or piping arrangements that effectively restrict the natural tendency of hot water to rise in vertical pipes during standby periods. Examples are the U-shaped arrangement of elbows or a 360-degree loop of tubing.
Heated Slab: Slab-on-grade construction in which the heating elements or hot air distribution system is in contact with or placed within the slab or the subgrade.
Heated Space: Space within a building that is provided with a positive heat supply (see "Positive heat supply"). Finished living space within a basement with registers or heating devices designed to supply heat to a basement space shall automatically define that space as heated space.
Heating Degree Days: A unit, based upon temperature difference and time, used in estimating fuel consumption and specifying nominal heating load of a building in winter. For any one day, when the mean temperature is less than 65°F (18°C), there exists as many degree days as there are Fahrenheit degrees difference in temperature between the mean temperature for the day and 65°F (18°C).
Heating Seasonal Performance Factor (HSPF): The total heating output of a heat pump during its normal annual usage period for heating, in Btu, divided by the total electric energy input during the same period, in watt hours, as determined by DOE 10 CFR Part 430, Subpart B, Test Procedures, and based on Region 4. Heat pump heating is expressed in terms of HSPF. New equipment ranges from about 6.8 to 10.0 HSPF. Higher HSPF ratings indicate more efficient equipment.
HID: High intensity discharge. Generic term describing mercury vapor, metal halide, high pressure sodium, and (informally) low pressure sodium light sources and luminaires.
High-Pressure Sodium Lamps: High-intensity discharge (HID) lamps whose light is produced by radiation from sodium vapor (and mercury).
High-Rise Residential Buildings: Hotels, motels, apartments, condominiums, dormitories, and other residential-type facilities that provide complete housekeeping or transient living quarters and are over three stories in height above grade. Hotels, motels, and other buildings with itinerant occupancies are covered by the "commercial" code regardless of height.
HSPF: See Heating Seasonal Performance Factor.
HUD: The U.S. Department of Housing and Urban Development
Humidistat: A regulatory device, actuated by changes in humidity, used for automatic control of relative humidity.
HVAC: Heating, ventilating, and air-conditioning
HVAC System: The equipment, distribution network, and terminals that provide either collectively or individually the processes of heating, ventilating, or air conditioning to a building.

I

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

ICAA: Insulation Contractors Association of America
ICBO: The International Conference of Building Officials
ICC: The International Code Council
IECC: The International Energy Conservation Code; formerly known as the MEC. The IECC was published in 1998 and 2000. The 2000 IECC with supplements was published in 2001.
IMC: International Mechanical Code
Indirectly Conditioned Space: An enclosed space within a building that is not a heated or cooled space, whose area-weighted heat transfer coefficient to heated or cooled spaces exceeds that to the outdoors or to unconditioned spaces; or through which air from heated or cooled spaces is transferred at a rate exceeding three air changes per hour. (Also see Heated Space, Cooled Space, and Unconditioned Space.)
Infiltration: The uncontrolled inward air leakage through cracks and interstices in any building element and around windows and doors of a building caused by the pressure effects of wind or the effect of differences in the indoor and outdoor air density or both. ARI 310/380.
Insulating Sheathing: An insulating board having a minimum thermal resistance of R-2 of the core material.
Insulation R-Values: R-values are used to rate insulation and are a measurement of the insulation's resistance to heat flow. The higher the R-value, the better the insulation.
Integrated-Control Economizers: Allows the cooling load of a building or space to be partially met by supplying outside air while the rest of the load is met by the refrigeration equipment within an HVAC system. Field- and factory-installed economizers supplied by major equipment manufacturers include integrated controls.
Integrated Part-Load Value (IPLV): A single number of merit based on part load EER or COP expressing part-load efficiency for air-conditioning and heat pump equipment on the basis of weighted operation at various load capacities for the equipment.
Interior-Lighting Controls: Offer the ability for systems to be turned on and off either manually or automatically and include switches, time clocks, occupancy sensors and other devices that regulate a lighting system.
Interior Lighting Power Limits: The maximum total wattage for a building or space that can be installed to meet the provisions of the energy code.
Interior Walls: Interior walls covered by Section 802.2.9 are those walls not on the exterior of the building and that separate conditioned and unconditioned space.

L

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Labeled: Devices, equipment, appliances, assemblies, or materials to which have been affixed a label, seal, symbol, or other identifying mark of a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of the production of the above-labeled items and by whose label the manufacturer attests to compliance with applicable nationally recognized standards.
Listed: Equipment, appliances, assemblies, or materials included in a list published by a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of listed equipment, appliances, assemblies, or material, and whose listing states either that the equipment, appliances, assemblies, or material meets nationally recognized standards or has been tested and found suitable for use in a specified manner.
Longitudinal Seam: A duct seam that is parallel to the direction of air flow.
Low-voltage Lighting: Lighting equipment that is powered through a transformer such as cable conductor, rail conductor, and track lighting.
Luminaire: A complete lighting unit consisting of a lamp or lamps, along with the parts designed to distribute the light, hold the lamps, and connect the lamps to a power source. Also called a fixture.

M

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

MEC: The Model Energy Code. The MEC was first published in 1983, with subsequent full editions published in 1986, 1989, 1992, 1993, and 1995.
Mechanical System: The system and equipment used to provide heating, ventilating, and air conditioning functions as well as additional functions not related to space conditioning, such as, but not limited to, freeze protection in fire protection systems and water heating.
Metal Building Walls and Roofs: Special attention to the design and construction of metal buildings is required to ensure these buildings meet the COMcheck-EZ requirements. Two key elements exist in metal buildings that are not found in other building classes - thermally broken connections between the purlin and metal roof sheet and compression of insulation behind wall girths and roof purlins.

COMcheck-EZ includes requirements for metal building walls and roofs. These requirements are specified in the "Walls Framed - Metal Framing" category and in the "Roofs Metal Purlin" category in the Prescriptive Packages. There are two classes of metal building roofs. One class uses traditional techniques that drape the insulation over the purlin and fasten the metal roof sheets through the insulation directly to the purlin. The second class requires that a thermal block be placed between the metal roof sheet and purlin.

A thermal block consists of foam blocks or other materials/techniques that prevent heat from migrating from the purlin directly to the metal roof sheet. Compressed fiberglass batt insulation does not qualify as a thermal block.
Metal Halide Lamps: A type of high intensity discharge (HID) lamp in which most of the light is produced by radiation of metal halide and mercury vapors in the arc tube. Available in clear and phosphor-coated lamps.
Multifamily: A multifamily building is a residential building three stories or less in height that contains three or more attached dwelling units. Multifamily buildings include apartments, condominiums, townhouses, and rowhouses. Hotels and motels are considered commercial rather than residential buildings.

N

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

NAECA: The National Appliance Energy Conservation Act of 1987, 42 USC 6291 et seq., as amended, Public Law 100-12.
NCSBCS: The National Conference of States on Building Codes and Standards
Net Wall Area: The net wall area includes the opaque wall area of all above-grade walls enclosing conditioned spaces, the opaque area of conditioned basement walls less than 50% below grade (including the below-grade portions), and peripheral edges of floors. The net wall area does not include windows, doors, or other such openings, as they are treated separately.
NFRC: National Fenestration Rating Council
NWWDA: National Wood Window and Door Association

O

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Occupancy Type: The type of activity occurring within a building.
Occupant-Sensing Device: A device that detects the presence or absence of people within an area and causes any combination of lighting, equipment, or appliances to be adjusted accordingly.
Opaque Areas: Opaque areas referenced in this guide include all areas of the building envelope except openings for windows, skylights, doors, and building service systems. For example, although solid wood and metal doors are opaque, they should not be included as part of the opaque wall area (also referred to as the net wall area).
Outdoor Air: Air taken from the outdoors and, therefore, not previously circulated through the system.

P

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Packaged Boiler: A self-contained unit that generally requires little maintenance.
Packaged Terminal Air Conditioner (PTAC): A factory-selected wall sleeve and separate unencased combination of heating and cooling components, assemblies, or sections (intended for mounting through the wall to serve a single room or zone). It includes heating capability by hot water, steam, or electricity.
Packaged Terminal Heat Pump: A packaged terminal air conditioner capable of using the refrigeration system in a reverse cycle or heat pump mode to provide heat.
Performance Approach: A performance approach (also known as a systems performance approach) allows you to compare your proposed design to a baseline or reference design and demonstrate that the proposed design is at least as efficient as the baseline in terms of annual energy use. This approach allows greater flexibility but requires considerably more effort. A performance approach is often necessary to obtain credit for special features, such as passive solar design, photovoltaic cells, thermal energy storage, fuel cells, and other nontraditional building components. This approach requires an annual energy analysis for the proposed design and the reference design. The COMcheck-Plus software automates this approach. We do not offer residential software products at this time to comply using this approach, but future versions of the REScheck software will include the DOE-2 energy analysis engine to perform the necessary calculations needed to determine compliance.
Permanently Wired Luminaires: Light fixtures physically attached to a surface (e.g. ceiling or wall) using a permanent mounting system and wired directly to a power source. Examples include fluorescent fixtures located in a ceiling grid and wall sconces.
Perm Rating: The amount of water vapor that passes through an area in a certain period of time.
Photocell: A light sensing device used to control luminaires and dimmers in response to detected light levels.
Plenum: An enclosure that is part of the air-handling system and is distinguished by having a very low air velocity. A plenum often is formed in part or in total by portions of the building.
Positive Cooling Supply: Mechanical cooling deliberately supplied to a space, such as through a supply register. Also, mechanical cooling indirectly supplied to a space through uninsulated surfaces of space-cooling components, such as evaporator coil cases and cooling distribution systems which continually maintain air temperatures within the space of 85°F (29°C) or lower during normal operation. To be considered exempt form inclusion in this definition, such surfaces shall comply with the insulation requirements of this code.
Positive Heat Supply: Heat deliberately supplied to a space by design, such as a supply register, radiator or heating element. Also, heat indirectly supplied to a space through uninsulated surfaces of service water heaters and space-heating components, such as furnaces, boilers and heating and cooling distribution systems which continually maintain air temperature within the space of 50°F (10°C) or higher during normal operation. To be considered exempt from inclusion in this definition, such surfaces shall comply with the insulation requirements of this code.
Prescriptive Packages Approach: A prescriptive packages approach lists the minimum R-value or maximum U-factor requirements for each building component such as windows, walls, and roofs. For lighting systems, a prescriptive approach would simply list the allowable watts per square foot for various building types. For mechanical systems and equipment, a prescriptive approach would list the minimum required equipment efficiencies. This approach is quick and easy to use, but you may find the approach somewhat restrictive because the requirements typically are based on worst-case assumptions and all requirements must be met exactly as specified. By locating the correct climate zone and looking up the appropriate table of packages, you can verify that your project meets one of the packages listed for that climate zone.
Projection Factor: The exterior horizontal shading projection depth divided by the sum of the height of the fenestration and the distance from the top of the fenestration to the bottom of the external shading projection in units consistent with the projection depth.

R

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Repair

A repair includes the reconstruction or renewal of any part of an existing building for maintenance purposes.

Raised Truss

Raised truss refers to any roof/ceiling construction that allows the insulation to achieve its full thickness over the plate line of exterior walls. Several constructions allow for this, including elevating the heel (sometimes referred to as an energy truss, raised-heel truss, or Arkansas truss), use of cantilevered or oversized trusses, lowering the ceiling joists, or framing with a raised rafter plate.

RECD

The Rural Economic and Community Development, formerly the Farmer's Home Administration.

Residential Buildings

For the purposes of the code, Group R residential buildings include:

Type A-1 - Detached one- and two-family dwellings
Type A-2 - All other residential buildings, three stories or less in height

R-Value

A measure (h ft2 °F/Btu) of thermal resistance, or how well a material or series of materials resists the flow of heat. R-value is the reciprocal of U-factor.

Roof Assembly

A roof assembly shall be considered to be all roof/ceiling components of the building envelope through which heat flows, thus creating a building transmission heat loss or gain, where such assembly is exposed to outdoor air and encloses conditioned space. The gross area of a roof assembly consists of the total interior surface of all roof/ceiling components, including opaque surfaces, dormer and bay window roofs, treyed ceilings, over-head portions of an interior stairway to an unconditioned attic, doors and hatches, glazing and skylights exposed to conditioned space that are horizontal or sloped at an angle less than 60° (1.1 rad) from the horizontal (see "Exterior wall"). A roof assembly or portions thereof having a slope of 60° (1.1 rad) or more from horizontal shall be considered to be in the gross area of exterior walls and thereby excluded from consideration in the roof assembly. Skylight shaft walls 12 inches (305 mm) in depth or greater (as measured from the ceiling plane to the roof deck) shall be considered to be in the gross area of exterior walls and are thereby excluded from consideration in the roof assembly.

S

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

SBCCI

The Southern Building Code Congress International, Inc.

Screw Lamp Holders

A lamp base that requires a screw-in-type light such as an incandescent or tungsten-halogen bulb.

Seasonal Energy Efficiency Ratio (SEER)

The total cooling output of an air conditioner during its normal annual usage period for cooling, in Btu/h (W), divided by the total electric energy input during the same period, in watt-hours, as determined by DOE 10 CFR Part 430, Subpart B, Test Procedures. New equipment ranges from about 10 to 16 SEER. Higher SEER ratings indicate more efficient equipment.

SEER

See Seasonal Energy Efficiency Ratio.

Service Water Heating

The supply of hot water for purposes other than comfort heating and process requirements.

SHGC

Solar heat gain coefficient; SHGC is the glazing's effectiveness in rejecting solar heat gain. SHGC is part of a system for rating window performance used by the National Fenestration Rating Council (NFRC). SHGC is gradually replacing the older index, shading coefficient (SC), in product literature and design standards. If you are using glass whose performance is listed in terms of SC, you may convert to SHGC by multiplying the SC value by 0.87.

Shading Coefficient

The ratio of solar heat gain through fenestration, with or without integral shading devices, to that occurring through unshaded 1/8-in.-thick double-strength glass.

Single Family

A detached one- and two-family residential building, irrespective of height.

Single-zone, Unitary HVAC Systems

Unitary HVAC systems that serve a single zone. Single zone systems can provide either heating or cooling, but provide supply air at the same volume and temperature to the entire zone which they serve.

Skylight

Glazing that is horizontal or sloped at an angle less than 60° (1.1 rad) from horizontal.

Slab Edge

Slab edge refers to the perimeter of a slab-on-grade floor, where the top edge of the slab floor is above the finished grade or 12 in. or less below the finished grade. The slab perimeter should include the length of all edges of a slab foundation that are part of the building envelope and are less than 12 in. below grade (i.e. all edges separating conditioned space from unconditioned space). The insulation can be installed using any of the following configurations, but in all cases it must start at the top of the slab:

The slab insulation extends from the top of the slab downward to the required depth.
The slab insulation extends from the top of the slab downward to the bottom of the slab and then horizontally underneath the slab for a minimum total linear distance equal to or greater than the required length.
The slab insulation extends from the top of the slab downward to the bottom of the slab and then horizontally away from the slab for a minimum total linear distance equal to or greater than the required depth. The horizontal insulation must be covered by pavement or at least 10 in. of soil.

The top edge of insulation installed between the exterior wall and the interior slab can be cut at a 45° angle away from the exterior wall.

Slab-On-Grade Floor

A floor that is poured in direct contact with the earth.

Slab-On-Grade Floor Insulation

Insulation around the perimeter of the floor slab or its supporting foundation when the top edge of the floor perimeter slab is above the finished grade or 12 inches (305 mm) or less below the finished grade.

Solar Heat Gain Coefficient

See SHGC.

Split System

Split-system HVAC equipment has the indoor and outdoor coils within separate cabinets. For a cooling only system, the outdoor cabinet would contain the condenser coil and the indoor cabinet would contain the evaporator coil.

Standard Truss

Any construction that does not permit the roof/ceiling insulation to achieve the required R-value over the exterior walls.

Structural Masonry Wall

A wall construction category used with masonry, precast and poured-in-place concrete, and concrete masonry units. In COMcheck-EZ™, you can select from among six specific types of masonry wall constructions by clicking the Ext. Wall button and selecting Structural Masonry Wall or by clicking the Basement button.

Switched Receptacles

The ability to turn power on and off to an electrical outlet by using a control switch.

T

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Tandem Wiring: A wiring option in which a ballast is shared by two or more luminaires. This reduces labor, materials, and energy costs.
Temperature Reset Controls: Controls that automatically reset supply water temperatures by representative building loads (including return water temperature) or by outside air temperature.
Thermal Bridge: A component, or assembly of components, in a building envelope through which heat is transferred at a substantially higher rate than through the surrounding envelope area.
Thermal Conductance: Time rate of heat flow through a body (frequently per unit area) from one of its bounding surfaces to the other for a unit temperature difference between the two surfaces, under steady conditions (Btu/h × ft²× °F) [W/(m² × K)].
Thermal Resistance (R): The reciprocal of thermal conductance
(h × ft² × °F/Btu) [(m² × K)/W].
Thermal Transmittance (U): The coefficient of heat transmission (air to air). It is the time rate of heat flow per unit area and unit temperature difference between the warm-side and cold-side air films (Btu/h × ft² × °F) [W/(m² × K)]. The U-factor applies to combinations of different materials used in series along the heat flowpath, single materials that comprise a building section, cavity airspaces and surface air films on both sides of a building element.
Thermostat: An automatic control device responsive to temperature.
Thermostat Set Back: Usually done at night to reduce the amount of conditioning provided at night by allowing the interior temperature to drift naturally to a marginal temperature during the night and then to recondition it to normal conditions in the morning.
Trade-Off Approach: A trade-off approach allows you to trade enhanced energy efficiency in one component against decreased energy efficiency in another component. These trade-offs typically occur within major building systems-envelope, lighting, or mechanical. You can, for example, trade decreased wall efficiency (lower R-value) for increased window efficiency (lower U-factor), or increase the roof insulation and reduce or eliminate slab-edge insulation. For lighting systems, the trade-off typically would occur between proposed lighting fixture wattages in various spaces within a building. The only trade-off allowed for mechanical systems and equipment is found in Chapter 8 of the IECC. You may trade off higher cooling equipment efficiency against a requirement for an economizer. Typically, this method is less restrictive than prescriptive approaches because components that exceed the requirements can compensate for those that do not meet the code. The REScheck and COMcheck-EZ software automates this approach.
Transverse Seam: All duct seams other than the longitudinal seam (which runs parallel to the direction of air flow).

U

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

UA: U-factor X Area; REScheck performs a simple UA calculation for each building assembly to determine the overall UA of your building. The UA that would result from a building conforming to the code requirements is compared against the UA for your building. If the total heat loss (represented as a UA) through the envelope of your building does not exceed the total heat loss from the same building conforming to the code, then the software declares that you pass. A high-efficiency equipment trade-off can also be performed.
U-Factor: A measure (Btu/h ft2 °F) of how well a material or series of materials conducts heat. U-factors for window and door assemblies are the reciprocal of the assembly R-value. The smaller the number, the less heat flow.
UL 181A: A test procedure for tapes and mastics used to seal ductwork.
UL 181B: A test procedure for tapes and mastics used to seal ductwork.
Unconditioned Space: An enclosed space within a building that is not a conditioned space.
Unitary Cooling and Heating Equipment: One or more factory-made assemblies that include an evaporator or cooling coil, a compressor and condenser combination, and that shall be permitted to include a heating function as well. When heating and cooling equipment is provided in more than one assembly, the separate assemblies shall be designed to be used together.
Unitary Heat Pump: One or more factory-made assemblies that include an indoor conditioning coil, compressor(s) and outdoor coil or refrigerant-to-water heat exchanger, including means to provide both heating and cooling functions. When heat pump equipment is provided in more than one assembly, the separate assemblies shall be designed to be used together.
Unitary-Packaged: Each package is a standalone system which provides all of the heating and cooling requirements for the area of the building which it serves.

V

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Vapor Retarder: A component that retards water vapor diffusion, but does not totally prevent its transmission. Vapor retarder material is usually a thin sheet or coating. However, a construction of several materials, some perhaps of substantial thickness, could also constitute a vapor retarder system.
Variable-Air Volume (VAV) System: HVAC system that controls the dry-bulb temperature within a space by varying the volume of heated or cooled supply air to the space.
Variable-Frequency Drive: Changes the speed of the motor by changing the voltage and frequency of the electricity supplied to the motor based upon system requirements.
Ventilated Naturally: The process of supplying or removing air by natural means to or from any space.
Ventilated Mechanically: The process of supplying or removing air by mechanical means to or from any space. Such air may or may not have been conditioned.
Ventilation: The process of supplying or removing air by natural or mechanical means to or from any space. Such air shall be permitted to be conditioned or unconditioned.
Ventilation Air: That portion of supply air that comes from outside (outdoors) plus any recirculated air that has been treated to maintain the desired quality of air within a designated space (see ASHRAE 62 and definition of "Outdoor air").
Visible Light Transmittance: The fraction of solar radiation in the visible light spectrum that passes through the fenestration.

W

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Wall: Opaque portion of the building envelope.
Water Heating: The process or system used to heat service water.
Water Temperature Reset: Temperature shall be reset by at least 25% of the design supply-to-return water temperature difference.
Window: The terms "fenestration", "window", and "glazing" are often used interchangeably. However, window actually describes a system of several components. Window is the term given to an entire assembly comprised of the sash, glazing, and frame.
Window Projection Factor: A measure of the portion of glazing that is shaded by an eave or overhang.
Window-Wall Ratio: The gross window area divided by the gross wall area.

Z

Top | A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Zone: A space or group of spaces within a building with any combination of heating, cooling, or lighting requirements sufficiently similar so that desired conditions can be maintained throughout by a single controlling device.