ABC Chart

A-Air Tightness, the highest rating for air is A3; B – Water Tightness, the highest rating for water is B7; C – Wind Load Resistance, the highest rating for wind is C5.

American Architectural Manufacturers Association (AAMA)

This trade association is the source of performance standards, product certification and educational programs for the window, door and skylight industry.


A treatment process to apply a protective coating to bare aluminum.


An apron is an interior trim component installed below the stool of a window.

Architectural Doors

Doors designed for commercial and industrial applications meeting specific standards of construction (e.g. fire rating, sound transmission). Generally used to represent higher standards than residential door requirements.


A natural, inert and chemically stable gas that replaces air between glass panes to increase R-value.


The center member of a double door, which is attached to the fixed or inactive door panel. Also prevents air infiltration.

Awning Window

A window with a sash that is hinged at the top and opens from the bottom.

Azurlite glass

This blue-tinted glass is popular in regions where shading is desired.


Back bead

Back bead is sealant that is applied on both sides when glazing an insulated glass unit into a sash or frame.


This is a material or compound used to seal the glass to a window sash.


This is the distance from the edge of a door to the center of the hole where the handle set or lock is inserted.

Ball bearing hinge

A commercial hinge option, used in applications where a door will get more than residential-type usage. Suggested for entry application and frequent-use areas, it reduces the rubbing friction of the hinge flange.

Bay Window

A bay window is made up of three or more windows. The side or flanker units project out from the building in 30, 45, or 90 degree angles. The center is parallel with the building wall and is made up of one or more windows. All the units can be stationary,

Block and tackle system

This pulley system is used to raise or shift a window sash.

Bow Window

A series of four or more adjoining window units, commonly five in number, projecting 10°-20° from the wall of the building, forming a radius.


A type of casing which frames windows and doors.


A form of exterior casing for windows and doors that serves as an aesthetic boundary between the siding and the frame.

Brickmould dimension

This refers to a dimension used in replacement applications.

Butt Hinge

The complete door hinge mechanism: the round central part (knuckle), flat portions (leaves or flaps), and the pin, which inserts into the knuckle.


Cam Lock

A single-point locking mechanism that uses a “cam” action to lock and to pull the window sash against the frame forming a tight weather seal; large windows may have more than one cam lock.


Deliniates shapes within the glass window like lead does in a stained glass window.

Casement window

A casement window is hinged on either side so the sash opens outward, to the right or left, in a swinging motion. It provides maximum ventilation.


Trim molding of various widths, thickness and shapes applied to the framework of window and door units.


Chalking is caused when the resin systems at the surface of a finish begin to degrade, primarily due to ultraviolet (UV) exposure. The resin and imbedded pigment particles then lose their ability to properly adhere to the surface. When this occurs, the pa

Check rail

On a double-hung window, the bottom rail of the upper sash and the upper rail of the lower sash, where the lock is mounted.


A generic term referring to any of a variety of window units with one or more curved frame members, often used over another window or door opening.

Clerestory window

A venting or fixed window above other windows or doors on an upper outside wall of a room.


Condensation occurs when excess humidity in warmer air is released in the form of water droplets onto a colder surface such as a pane of glass.

Condensation Resistance Factor (CRF)

CRF is a rating that indicates a window’s ability to resist condensation. The higher the CRF, the less likely condensation is to occur.

Cottage double-hung

A double-hung window in which the upper sash is shorter than the lower sash.



This is a drying agent, such as silica gel, that’s used in manufacturing of insulated glass between the panes to prevent fogging of the insulated unit. It is an extremely porous crystalline substance used to absorb moisture from within the sealed air spac

Dew Point

The temperature at which condensation occurs.

Door Bevel

An angled cut on the lock side of a door, usually 3 degrees, that enables it to swing free of the door frame when opening and closing.

Door casing

A door casing is a piece of trim that surrounds the jamb of the door or entry system.

Door Core

A core placed inside the door to provide either strength or fire rating. Core types are corrugated honeycomb paper, polyurethane foam, particleboard, wood stave, and mineral fiber.

Door Frame

A complete door frame consists of two jamb legs available rabbetted (built-in stop) or with a separate stop applied (stitched) and one header, also with stop applied with staples. Once installed in the rough opening, a door may be hung on the frame.

Door lite

A door lite is a glass insert installed in a door panel.

Door striker

This component is a slightly beveled metal plate, which is set into a door jamb to receive and guide a door latch to its socket when closing.


A space which protrudes from the roof of a house, usually including one or more windows.

Double glazing

Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits.

Double-hung window

A window unit that has two operable sashes which move vertically in the frame.

Drip cap

A molding placed on the top of the head brickmold or casing of a window frame.

Dual durometer

A material that has two or more levels of flexibility.

Dual-arm operator

This type of hardware is used to open awning and casement windows. It is composed of two arms - one pulls the sash, while the other pushes.


E-Gard® hardware

Window hardware made with a multistage coating process to protect both steel and zinc parts from the effects of cleaning agents as well as corrosion caused by acid rain, ultraviolet radiation, and wood preservatives. This hardware is not manufactured by J

Egress Code

Building requirement defining the minimum opening of a window to allow for safe exit in case of emergency.

End Rails

Rails at each end of door.


A form produced by forcing material through a die. Our window frames are constructed with extruded vinyl.



A fabricator is the person or firm that assembles all the component parts into a complete window, door or sash unit.


An architectural term referring to the arrangement of windows in a wall. From the Latin word, "fenestra," meaning window.

Fire Door

Fire doors are designed to meet independent testing facilities' (Underwriter's Laboratory [UL] and Warnock Hersey [WH]) standards for fire ratings 20, 30, 45, 60 and 90 minutes. The desired rating is achieved by using special door core and frame material.

Fire-Rated Door

A door that is noncombustible in the average structure fire for a minimum period of time. A fire-rated door takes a certain number of minutes to burn; usually 20, 60 or 90 minutes.


Refers to a window or door that is non-venting or inoperable.


The two end windows in a multiple unit.


A thin strip of metal or synthetic material that diverts water away from a window or skylight.

Flush bolt

A flush bolt is a mechanical fastening device found at the bottom and top of the T-astragal of a French, garden or swing door with active and inactive panels. Used to hold the inactive door of the French door unit closed.


Fogging is a deposit or film left on an interior surface of a sealed insulating glass unit. It occurs due to extreme conditions or failed seals.

Folding crank handle

This type of hardware is used to operate casement windows; the handle folds away when not in use.


The enclosure in which window sash or door panels are mounted.

Frame Size

The overall width and height excluding brick moulds of a window or a group of windows. Width measurement always precedes height.

Full screen

This type of screen fills the entire window opening of a double-hung window.



Glass in a window or door; the act or process of fitting with glass.

Glazing stop

The part of the sash or door panel which holds the glass in place.

Glue Chip glass

This type of glass features a feathered or frost-like texture and provides an obscured view.


A term referring to windowpane dividers or muntins. When between two panes of glass, they will last longer and allow for ease of cleaning.


Half screen

This type of screen does not fill the entire opening of a double-hung, single-hung or half-slide window. It only covers one sash.


The main horizontal member forming the top of the window or door frame.


A horizontal framing member placed over the rough opening of a window to prevent the weight of wall or roof from resting on the window frame.

Heat Loss

The heat transmission rate multiplied by the area of the door.


The vertical door dimension. Standard residential door heights are 78" to 80".


A window unit in which the top of the sash swings inward.



Heat loss due to air escaping through cracks or spaces around an exterior door.

Insulating glass (IG)

A combination of two or more panes of glass with a hermetically sealed air space between the panes of glass. This space may or may not be filled with an inert gas, such as argon.


Where the upper and lower sash meet on a vertical or horizontal slider, the interlocking mechanism brings the two sashes together for a tighter seal.


Jamb extensions

Used to bridge the distance from the window to the casing.


The main vertical members forming the sides of a window or door frame. Jambs are of various widths and thickness. The most common sizes are 11/16" thick by 4-9/16" wide (for interior use).


A J-channel is a space that allows a home’s siding to slip between the trim and nailing fin. This feature also allows for easy installation and produces a clean, streamlined appearance.


Trim used to finish the window both functionally and aesthetically on the exterior. Allowing siding to fit behind the front of the moulding for a cleaner and attractive look.



A lock which, when activated, prevents the sash from opening.


A groove that often holds weatherstrip.

Keyed lock

A keyed lock is a mechanism using the same key configuration as other locks in a home or building.

Knocked down (KD)

Unassembled window or door unit. Pre-machined & ready-to-assemble, with a matching jamb and header.


Laminated glass

This glass is constructed by placing a plastic interlayer between two panels of glass. The interlayer helps protect the glass from impacts and prevents shattering.

Lean manufacturing

This is a business philosophy and strategy that’s focused on eliminating all manufacturing steps or processes that do not add value to the final product or service.

Legs Legs

Commonly called jambs - The side pieces of the door frame running vertical.


A condition that exists when a surface is exactly horizontal.

Lift Rail

The lip that is attached to the sash of a slider window to allow the homeowner to grasp and open the window.


A separately framed piece of glass in a window or door. A traditional single-hung window, for instance, often has several lights divided by muntins in each sash. Such windows are described as six-over-six, eight-over-one, twelve-over-twelve, etc., to indi

Low-E glass

This type of insulating glass significantly blocks harmful ultraviolet (UV) rays and the sun’s infrared heat, so homes stay cooler in the summer and interior furnishings fade less. In the winter, it helps keep homes warmer and reduces condensation.


Masonry opening

This is the opening in a masonry wall, which accepts a window or door unit, the same as a rough opening in a frame wall.


Fire rated core of a door available in 45 min., 60 min., & 90 min. versions.


The joint created when two windows are attached to each other at the jambs and head.

Multipoint locking system

A multipoint locking system has more than one locking point.

Muntin Bars

Also known as grills or blocks, the grid between two pieces of glass in a thermal unit.

Muntin/Muntin Bars

Any short or light bar, either vertical or horizontal, used to separate glass in a sash into multiple lights. Also called a windowpane divider or a grille.


Nailing Flange

The perforated part of a vinyl window that allows the window to be face-nailed to the sill or sheathing that acts as a temporary fastening method.

National Fenestration Rating Council (NFRC)

The NFRC is an independent third-party certification organization with industry-accepted standards for evaluating and certifying energy performance. The NFRC Certificate contains U-factor, SHGC (Solar Heat Gain Coefficient), and VT (Visible Transmittance)

Night Security Latch

A safety device available on Premier Plus® vertical sliders that allows the sash to be open a few inches for ventilation, but prevents maximum opening.


A no-bore door does not include cavities to fit a door knob, handle, lockset or other hardware.


A nominal dimension is the industry term used to approximate a door size.


Obscure glass

This is any type of decorative textured glass that fully or partially obscures the view. It allows for privacy while still letting light enter a home.


Palladian window

A large, arch-top window flanked by smaller windows on each side.


A piece of glass.

Panic hardware

This is a locking system that allows for the quick opening of commercial exit doors, such as hospitals, universities and schools, concert halls, shopping centers, hotels and offices.


These elements are gables placed over a door or window. They generally include horizontal moulding (i.e., a cornice).

Picture frame casing

This type of weatherstrip that has pile (or “fuzz”) that helps reduce air or dust around a window sash or door panel.

Picture Window

A fixed window typically of a large size in relation to adjacent windows.


Pilasters are decorative elements that emulate engaged piers or pillars.


A condition that exists when a surface is exactly vertical.

Prairie grilles

This type of divided lite grille pattern borders the glass on the perimeter of the frame or sash. Also known as Queen Anne grilles.


Polyvinyl Chloride (PVC) is an extruded or molded plastic material framing and a thermal barrier.



A quarter-round is a radius and geometric shape available for vinyl and aluminum windows.


Rail Rail

The top and bottom horizontal members of the framework of a window sash.

Raised Panel Door

A flush door using a raised door facing (slab) that has been hydraulically pressed to create a simulated raised panel design and may have either a smooth or textured finish.


An interior trim attachment to accept drywall or wood – 1/2” or 3/4”.

Rough opening

The pre-finished framed opening in a wall into which a window or door unit is to be fitted.

Round top

This is a feature on a window or door with a 180-degree curve at its top. It is also called a true radius top.


Rough Stud Opening or the size of hole in which the window will be installed including an allowance for shimming.


Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.



An assembly of stiles and rails that forms a frame for holding the glass in a window.

Sash Balance

The mechanism that balances the load of the sash.

Sash Lock

In an operating or opening window, locks are provided for extra security and tightness of the unit.

Sash snubber

This component on a window ensures the sash seals tightly against the frame.


Simulated Divided Light. Grill bars are applied to exterior and interior surface for old-fashioned look.

Seal failure

This is the loss of the hermetic seal around the perimeter of the insulated glass (IG) unit which results in fogging between the panes of the IG unit.

Segment top

This is a feature on a window or door that’s rounded at its top.

Setting Block

Small pieces of vinyl or rubber in the bottom rail to protect and support the insulating glass unit.


Narrow fixed units mulled or joined to door units to give a more open appearance.

Sight lines

These visual lines are used to align sash or panels of mulled units or units placed on the same elevation.


The bottom part of the frame of a window or door.

Simulated divided lites

This divided lite option offers the most authentic true divided lite appearance. It includes interior wood bars, optional shadow bars between the glass, and exterior metal bars that are permanently attached to the exterior glass.

Single glazing

Use of single panes of glass in a window. Not as energy-efficient as double glazing.


A type of window in which the top sash is fixed or inoperable.

Single-hung side-load window

A window with stationary top sash and a bottom sash that slides vertically. It also features a side-load removable sash that makes cleaning particularly easy.


A window installed in the roof to allow more light and sometimes heat into the structure. Depending on which direction they face, skylights can bring in more light and heat than windows.


Main surfaces of a door. HOMEGUARD® door slabs are 24 gauge hot dipped galvanized steel faces, primed white or factory painted white and carry a 10 year rust and corrosion resistance warranty.

Sliding Patio Door

A door with one or more panels that slide horizontally.

Solar Heat Gain Coefficient (SHGC)

Solar heat gain coefficient is a measurement of the amount of solar radiation through a piece of glass or door material. The lower the SHGC, the fewer UV rays that cause heat gain come through the glass.

Solid Core (S.C.)

Wood block, particleboard or fire-rated mineral fiber used in the core of a door. Solid Core doors are either flush or raised panel.

Stacked Unit

A combination unit where one unit is fixed on top of another.


The main vertical members of the framework of a sash.


An interior trim piece on a window which extends the sill and acts as a narrow shelf.


A molding used to hold, position or separate window parts; wood or metal strip attached to jambs and header, with or without for and to keep door from swinging through.

Stress crack

A defect in an insulated glass unit, this type of crack results from a stress condition on the edge of the glass.

Super Spacer®

Silicone foam spacer bar that reduces thermal transfer at edge of glass. Also called Warm Edge


This is the weather-strip attached to the bottom of a door.


Tempered glass

Glass manufactured to withstand greater than normal forces on its surface. When it breaks, it shatters into small pieces to reduce hazard. Standard on all ALLSCO patio doors.

Thermal break

The addition of a thermal insulating material between two thermally conductive materials.

Thermal Transfer

The movement of heat or cold through a substance.

Thermal Unit

Two pieces of glass separated by a spacer to allow for a dead air space that gives the window extra insulation value.


The depth dimension of a door. Standard residential door thicknesses are 1-3/8" and 1-3/4".


This is a frame component on a swing door designed to act as a barrier to external elements.

Tilt latch

A tilt latch is a mechanism at the end of a window checkrail that allows a sash to release from the jamb liners and tilt into the structure.

Tinted glass

This glass has a subtle coloring (usually grey, bronze or green) that protects a home’s interior harsh direct sunlight.


A window, usually rectangular, placed over a door or window. Transoms, or fanlites, were first used in the 18th century on exterior doors. They increased the amount of light let into the front hall, and because of them, the size of the front door could be


This is a four-sided geometric shape available for a vinyl or aluminum picture window frame bar.


This is a three-sided geometric shape available for a vinyl or aluminum picture window frame bar.

Triple Glazing

Three panes of glass with an airspace between each pane.

True Divided Lite

A window opening comprised of multiple individual smaller panes of glass separated by muntins.



U-factor or U-value is a number that represents the rate of heat loss through a window or door. The lower the number, the greater a window resists the transfer of heat. A U-factor of 0.35 or lower represents good insulating value.

Ultraviolet (UV)

UV refers to the type of rays outside of the visible spectrum (at its violet end). These rays are found in everyday sunlight and can cause fading or chalking of dark paint finishes. Extreme UV exposure can cause certain plastic materials to distort.


Unplasticized polyvinyl chloride makes vinyl rigid. All Atlantic Windows are made of UPVC.


Rate of heat flow-value through the complete heat barrier, from room air to outside air. The lower the U-value, the better the insulating value.


Vent Unit

A window or door unit that opens or operates.

Vinyl (PVC)

A thermally efficient, long lasting, structurally sound material used by ALLSCO to make window and door frames.



A material or device used to seal the openings, gaps or cracks of venting window and door units to prevent water and air infiltration.

Weep Hole

The visible exit or entry part of a water drainage system used to drain water out of a window or patio door.

Window and Door Manufacturers Association (WDMA)

The Window and Door Manufacturers Association (WDMA) researches, tests and provides certifications for windows and doors.

Window Styles

Single hung, double hung, single horizontal, double horizontal, casement, awning, octagonal and specialty shapes.



From the outside looking in for sliding fenestration products, the O represents the fixed sash and X represents the operating sash.

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