IBC - International Building Code.

ICC - International Code Council. A national organization that publishes model codes for adoption by states and other agencies. Codes include the International Residential Code (IRC), International Building Code (IBC) and the International Energy Conservation Code (IECC).

IECC - International Energy Conservation Code published by the ICC. The successor to the Model Energy Code, which is cited in the 1992 U.S. Energy Policy Act (EPAct) as the baseline for residential Energy Codes in the United States.

IGCC - Insulating Glass Certification Council - directs a certification program of periodic accelerated laboratory testing and unannounced plant inspections to ensure sealed insulating glass performance is in conformance with ASTM E 774-88.

IGMA - Insulating Glass Manufacturers Alliance.

Inactive Door or Leaf - The last door of a pair of doors to be released when unlocking, usually the one not equipped with a primary lock.

Incompatibility - Adverse reaction.

Infill - Various materials glazed into a framing system.

Infiltration - See air leakage.

Infrared Radiation - Invisible, electromagnetic radiation beyond red light on the spectrum with wavelengths greater than 0.7 microns.

Inside Snap Trim - Used in retrofit work to cover the inside gap between the new window and the existing opening.

Insulated Shutters - Insulating panels that cover a window opening to reduce heat loss.

Insulating Glass Unit (IG) - An integral glass unit made up of two or three individual lights of glass separated by an air space.

Insulating Value - See U-factor.

Insulation - Material that has the ability to reduce heat or cold transmission.

Integral Mullion - A frame member trapped within the master frame to separate vents or fixed glass.

Interior Glazing - A method in which glass is secured in an opening from the interior of the building.

Interlock - An upright frame member of a panel in a sliding window or sliding glass door which engages with a corresponding member in an adjacent panel when the window or door is closed. Also called Interlocking Stile.

Intermediate Butt Hinge - A butt hinge located between the top and bottom hinges on a door.

IRC - International Residential Code.

Jack Stud - Vertical framing members, generally 2x4's, which form the inside of the window or door rough opening. They support the header and run down to the sole plate.

Jalousie - Window made up of horizontally-mounted louvered glass slats that abut each other tightly when closed and rotate outward when open.

Jamb - The end vertical member of an aluminum framing system which terminates at the intersection of a wall. It is often referred to as a wall jamb.

Jamb Anchor - A metal device inserted in the back of a metal frame to anchor the frame to the wall. A masonry anchor is used in a masonry wall and a stud anchor in a wall built with wood or metal studs.

Jamb Extension - Pieces of material used to extend the depth of the jamb to equal the depth of the rough opening.

Jamb Liner - In a double-hung window, the track installed inside the jambs on which the window sashes slide. Vinyl or metal covering applied to the side jambs of double-hung and single-hung windows. They are generally formed to include an integral balance system and stops for the exterior and interior surfaces of the sash.

Joint Design - The design of a void to be filled with sealants to prevent air or water leakage.

Keeper - Part of a door or window that the lock latches onto.

Kerf - The channel or groove cut by a saw or other tool.

Keyed-Alike Cylinders - Cylinders operated by the same key. (Not to be confused with master-keyed cylinders.)

Keyed-Different Cylinders - Cylinders requiring individual keys for their operation.

Keyway - The keyhole of a cylinder lock.

Kick Plate - A plate applied to the face on the bottom of a door or sidelight to protect against abrasion or impact loads or maintain sight lines.

King Stud - A full-length stud nailed to the end of the header.

Knob - A round handle for actuating a locking or latching device.

Knocked Down (kd) - Unassembled window or door unit. Not including glass.

Knuckle - The parts of a butt hinge which enclose the hinge pin.

Krypton - An inert, nontoxic gas used in insulating windows to reduce heat transfer.

KWH - KiloWatt Hour. A unit of energy or work that is equal to one-thousand watt-hours.

Laminated glass - Two or more sheets of glass with an inner layer of transparent plastic to which the glass adheres if broken. Used for safety glazing and sound reduction.

Latch - A mechanism having a spring-activated beveled latch bolt. Retraction of the latch bolt is by lever handle or knob.

Latch Lock - See Lock.

Leaf - An individual door used either in a single or multiples (leaves).

LEED - Leadership in Energy and Environmental Design. Rating system for the design, construction, and operation of high-performance green buildings.

Left or right sliding - Location information, always outside looking in, that is used to specify direction, e.g., "the operating sash slides to the right."

Level - The condition of perfect horizontal alignment.

Lever Handle - A bar-like grip which is rotated about an axis at one of its ends to operate a locking or latching device.

Lift - Handle for raising the lower sash in a single-hung or double-hung window. Also called Sash Lift.

Light or Lite - A separately framed piece of glass in a window or door. Sometimes spelled 'Lite." A single (monolithic) glass pane or piece.

Light-to-Solar-Gain Ratio - A measure of the ability of a glazing to provide light without excessive solar-heat gain. It is the ratio between the visible transmittance of a glazing and its solar-heat gain coefficient.

Lintel - A horizontal structural member that spans an opening at the head to carry the weight of construction above the opening.

Liquid Crystal Glazing - Glass in which the optical properties of a thin layer of liquid crystals are controlled by an electrical current, changing from a clear to a diffusing state.

Lite - Same as Light.

Liveload - Loads from non-permanent parts of the building (window washing and glazing rigs are liveloads).

Lock Backset - Distance from the edge of the locking stile to the centerline of the cylinder, measured parallel to the face of the door.

Lock Face Plate - The exposed plate set on the edge of a door to cover a locking mechanism.

Lock, Dead lock - A lock in which a bolt is moved by means of a key or thumb turn and is positively stopped in its projected position.

Long-Wave Infrared Radiation - Invisible radiation, beyond red light on the electromagnetic spectrum (above 3.5 micro meters), emitted by warm surfaces such as a body at room temperature radiating to a cold window surface.

Louvers - Glass, metal, or vinyl slats, either movable or fixed; as in a Jalousie window

Low-Conductance Spacers - An assembly of materials designed to reduce heat transfer at the edge of an insulating window. Spacers are placed between the panes of glass in a double- or triple-glazed window.

Low-E Glass - Low emissivity glass; a type of reflective glass used to reduce radiation heat transfer and improve the U-value of the glazing.

Low-Emittance (Low-E) Coating - Microscopically thin, virtually invisible, metal or metallic-oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow. A typical type of low-E coating is transparent to the solar spectrum (visible light and short-wave infrared radiation) and reflective of long-wave infrared radiation.

Marine Glazing - A U-channel of soft PVC which is wrapped around the edge of the glass, cushioning the glass against the aluminum or vinyl. This process allows for unrestricted expansion and contraction and watertightness masonry opening. The space in a masonry wall left open for windows or door. The opening in a masonry wall to accept a window or door unit; also known as a rough opening in a frame wall. The header (or lintel) in a masonry opening is usually a steel beam.

Master Key - A key that will operate a number of different locks, each of which is different from the rest.

Master Keying - A system of keying cylinders so that one master key will operate all of them, secondary keys will operate only certain groups, and other keys will operate only certain individual cylinders.

Medium Stile - See Stile.

Meeting rail - The part of a sliding glass door, a sliding window, or a hung window where two panels meet and create a weather barrier.

Meeting Stile - The stiles of the active and inactive leaves which meet when a pair of doors is closed.

Micron - One millionth (10-6) of a metric meter.

Mil - One thousandth of an inch, or 0.0254 millimeter.

Mill Finish - The original finish of aluminum before finishing.

Miter - A joint made up of two members, each of which is cut one-half the total angle of the joint.

Model Building Code - A construction code developed from input from industry, building officials, and others for use as a guide for the development of state and local building codes. Model building codes have no legislative or jurisdictional power.

Model Energy Code (MEC) - The Model Energy Code is cited in the 1992 U.S. Energy Policy Act (EPAct) as the baseline for residential Energy Codes in the United States. It has been succeeded by the International Energy Conservation Code (IECC).

Mortise - A rectangular cutout which is fabricated in the aluminum entrance door and/or frame in preparation to receive a lock or butt hinge.

Mortise Lock - A lock designed to be installed in a mortise on the stile of the door rather than applied to the door's surface.

Mortise Type - Possesses a threaded surface for screwing it directly into a lock case and has a cam on the interior end which engages the lock mechanism.

Mortise-And-Tenon - A strong wood joint made by fitting together a mortise in one board and a matching projecting member (tenon) in the other.

MSDS - A Material Safety Data Sheet is a detailed information bulletin prepared by the manufacturer or importer of a chemical that describes the physical and chemical properties, physical and health hazards, routes of exposure, precautions for safe handling and use, emergency and first-aid procedures, and control measures. Information on an MSDS aids in the selection of safe products and helps prepare employers and employees to respond effectively to daily exposure situations as well as to emergency situations.

Mullion - A major structural vertical or horizontal member between window units or sliding glass doors.

Muntin - A secondary framing member used to hold panes within a window, window wall or glazed door.

Nail Fin - A fin on a window or door that is used to fasten the product into a rough opening. Usually not seen after installation is complete.

Narrow Stile - See Stile.

Neoprene - A synthetic rubber having physical properties closely resembling those of natural rubber but not requiring sulphur for vulcanization. Extremely good weather resistance (both heat and cold) with ultraviolet stability. Commonly used for commercial glaze.

NFRC - National Fenestration Rating Council.

Nite Latch - Hardware which, when engaged, restricts the sash opening to a predetermined dimension.