Term Definition
Air Infiltration Air that leaks into a building through cracks or gaps.
Approved Contractor A contractor approved by the organization offering the incentive.
Attic Cards Attic cards (supplied by manufacturers of blown-in insulation) show the type and R-value of the insulation, the thickness as well as the installer's name and company address. They should be placed near the attic opening.
Attic Rulers

When blown insulation is used, NAIMA recommends that attic rulers should be installed, one for every 300 square feet of attic area.  The installed thickness of blown insulation should not be less than the minimum settled thickness on the attic card.  The Federal trade Commission does not require attic cards, but it is typical practice and helpful to the current and future homeowner. Consult CABO/MEC Guidelines on attic cards & rulers.

Baffles Device to maintain a ventilation space between the insulation and roof deck, assuring air flow from the eave/soffit vents to ridge vent or other roof vents provided in attics and cathedral ceilings.
Batts Pre-cut pieces of insulation in standard sizes; batts may have a facing of kraft paper, aluminum foil or poly (plastic) or no facing at all.
Blankets Rolls of Insulation; may have facing of kraft paper or aluminum foil backed paper.
Blow-In-BlanketĀ® Systems (BIBS) A patented application process that combines loose-fill and mineral wool fiber glass insulation with a fine adhesive mist, then blows it into a home's cavities behind netting.
Builders/Developers Those who build or develop houses, housing units or commercial structures.
Building Envelope The exterior assembly that encloses the interior space of a building. It serves as the outer shell to protect the indoor environment as well as to facilitate its climate control. Building envelope design is an application area that draws from all areas of building engineering, especially building science and indoor climate control. Building envelope design includes four major performance objectives: Structural integrity, Moisture control, Temperature control, Control of air pressure boundaries (this includes air movement into and out of the interior space and through the components of the building envelope-interstitial)). The physical components of the envelope include the foundation, roof, and walls, along with the insulation encompassed in these components, as well as the doors and windows.
Cavity The empty space between studs or joists typically filled with insulation.
Commercial Pertaining to incentives available to owners of businesses that may be housed in buildings or structures other than homes.
Condensation The liquid water that results when water vapor from the air changes to liquid form. This commonly occurs when warm moist air comes in contact with cold surfaces.
Conduction The direct transfer of heat through building elements such as walls, ceilings, floors, and windows. This is a major area of home heat loss.
Convection The transfer of heat energy by air or fluid movement. This motion is a spontaneous circulation due to the combined actions of gravity and changes in air or fluid density. In space heating, the operation of a baseboard heater is a good example of convection.
Crawlspace Vents An opening to allow the passage of air through the unfinished area under a first floor. Ideally there should be at least two vents per crawlspace. Refer to your local building code for requirements in your area.
Density The mass of a substance per unit of volume of that substance.
Eligibility The types of structures eligible for the incentive.
Energy Code Local requirement that outlines the minimum level of insulation and other energy-efficiency measures for new construction. Energy Codes are updated on an ongoing basis, and minimum levels of insulation are set by considering the cost of energy and what level provides a reasonable payback.
Energy Efficient Mortgage A mortgage that offers favorable terms to homeowners and/or business owners in order to finance the purchase of energy efficient buildings or make energy efficient upgrades.
Existing Buildings Homes or commercial structures currently standing.
Face Staple Stapling facing flange to the front side of a stud or rafter, along the 1-1/2" dimension.
Faced Insulation Insulation with a facing already attached. Kraft paper or foil-backed paper are common facings.
Fiber Glass Insulation An effective resistor of heat flow that is made from molten sand and recycled glass which is spun into fibers.
Fiber Glass or Glass Fibers Glass in a strand form.
FSK Foil Skrim Kraft (FSK) is a reflective facing that is laminated to fiber glass insulation. When exposed (where codes permit), the reflective surface helps maximize lighting efficiency and may reduce lighting requirements. It also serves as a excellent vapor retarder.
Grant A sum of money given for a specific purpose.
Heat Flow The rate at which heat moves from an area of higher temperature to an area of lower temperature. Btu/hr (W/hr). Heat flow is generally used to quantify the rate of total heat gain or heat loss of a system.
Home Audit or Energy Audit An assessment performed by an energy specialist in order to identify how a structure's energy efficiency can be improved. Many incentives or rebates require an audit be conducted before and after the improvements in order to verify savings.
HVAC Acronym for Heating, Ventilation and Air-Conditioning systems.
Incentive Type The form of financial assistance offered by utilities, states, and/or local organizations to encourage homeowners and/or businesses to increase energy efficiency. Examples include loans, rebates, grants, tax incentives, and free services.
Industrial Pertaining to incentives available to owners of businesses in the manufacturing environment where incentives are given for improving the energy efficiency of a manufacturing process.
Inset Staple Stapling to the inside portion of the stud or rafter.
Insulation Density Denser insulation products have more fibers per square inch and generally have greater insulating power through higher R-values.
Insulation Type The type of insulation eligible for the incentive (wall, ceiling, pipe, etc.).
Joist Horizontal framing member to support the floor or ceiling.
Knee Walls Walls of varying length. Used to provide additional support to roof rafters with a wide span or to finish off an attic.
Kraft-Faced Vapor Retarder Created by coating kraft paper with a thin layer of asphalt adhesive. The coated side of the kraft paper is then applied to the unfaced insulation material. The asphalt adhesive bonds the kraft paper and the insulation together, which acts as a vapor retarder. Kraft-faced vapor retarders are combustible and should never be left exposed in a building. See Vapor Retarder
Loan A sum of money lent at interest.
Loose-Fill Insulation Small pieces of insulation, made from fiber glass, mineral wool that is blown into a home using a machine that houses a blowing machine. Loose-fill insulation is typically installed by a professional. Loose-fill is used for general purposes and is especially effective at filling small and irregularly-shaped spaces.
Low-Income A household with a combined income that qualifies them for certain incentive programs. The definition of low-income can vary from organization to organization and is expressed in relation to the Federal poverty level Contact the organization offering the incentive for more information.
Manufactured Home A house that is put together in standardized sections that are built off-site in a factory.
Mineral Wool A broad term used typically to refer to rock wool and slag wool. In some countries, this term is also used to refer to fiber glass.
Mortgage Rate Reduction A favorable mortgage rate granted to homeowners and/or businesses to finance the purchase of energy efficient buildings or make energy efficient upgrades.
Multi-Family A structure housing more than one family.
NAIMA North American Insulation Manufacturers Association, a trade organization representing manufacturers of fiber glass and rock and slag wool insulation products in North America.

This is a technical term used in the building industry to refer to products that are not capable of combustion. The glass fibers in fiber glass insulation and the rock and slag wool in mineral wool insulation have a natural fire resistance and are considered non-combustible when tested in accordance to ASTM E136.

Personal Tax Incentive A deduction or tax credit on an individual income tax return for the purchase (and in some cases, installation) of energy efficiency products.
Post-Project Inspection/Rating An assessment performed after energy efficiency improvements are made.
Radiation The transfer of heat by direct rays traveling through space to a solid substance, but without heating the air (similar to light rays). An example is the sun warming the earth. Radiant heat can also be reflected (via a mirror) or absorbed (through dark clothing).
Rebate A deduction from an amount charged or a return of a price paid.
Requirements The criteria an applicant or project must meet in order to receive an incentive, or steps that must be taken in order to receive the incentive, such as having a home energy audit performed or using an approved contractor.
Residential Pertaining to a home or homes.
Rock Wool Insulation Man-made material comprised of natural minerals like basalt or diabase which are spun into a fibrous form.

The measure of resistance to heat flow. Insulation materials have tiny pockets of trapped air. These pockets resist the transfer of heat through material. The ability of insulation to slow the transfer of heat is measured in R-values. The higher the R-value, the better the insulation material's ability to resist the flow of heat through it. The Federal Trade Commission prohibits expressing R-value in terms of inches, because R-value is not a linear measurement.

Sales Tax Incentive A reduced sales tax rate or an exemption from paying sales tax on energy efficiency products.
Single Family House A structure housing no more than one family.
Slag Wool Insulation Man-made material made primarily from iron ore blast furnace slag which is spun into a fibrous form.
Sound Transmission Class (STC) A numerical rating of the sound control performance of a wall or ceiling; the higher the number, the better the sound control.
Stapling Flange A protruding edge on faced insulation used to staple the insulation to the framing.
Stud An upright metal or wood post in the framework of a wall for supporting an approved interior material such as gypsum wallboard.
Unfaced Insulation Insulation with no attached vapor retarder.
Vapor Retarder A material which retards the transmission of water vapor. It is rated in perms ("permeance"). The lower the perm rating, the better the water vapor permeance. A vapor retarder should have a perm rating no greater than 1.0.
Ventilation Creates a positive flow of air that allows the house to “breathe” and helps prevent moisture build-up year round.
Warm-in-Winter Side Refers to the living area of a house in climates where it is colder outside in the winter than it is inside. This is useful information for determining the proper placement of a vapor retarder.
Weatherization Free services or grants available to low-income households for improvements to the thermal efficiency of dwellings (typically insulation, caulking, and weatherstripping).
Disclaimer: The definitions offered herein are generic definitions and may not precisely reflect legal or technical definition provided by governmental or other sources.