Active Panel

Primary operating door panel.

Argon Gas

Colorless and odorless gas that is less dense than air. It is used to fill the air space between glass panes to increase energy efficiency.


Two or more window units mulled (attached) together to create one larger grouping.


A vertical moulding attached to a panel of a door against which the other panel closes. Usually head and footbolt devices will be found on the astragal side.

Awning Window Unit

A top-hinged window that swings out from the bottom with crank-out hardware.

Bay Windows

A series of windows installed in an angled “bay” formation with a head and seat board. Typically, two smaller operating units flank a larger fixed center window.

Bow Windows

A series of adjoining window units that are configured in a gradual arc.

Brick Mould Casing (BMC)

Borders the exterior material of the window. The casing serves as the boundary moulding for brick or other siding material.

Cam Lock

A lever operated lock used to prevent intrusion through the sash.

Capillary Tubes

A tube inserted into the insulating glass spacer that allows the inside and outside air pressure to equalize in higher elevations.

Casement Window

A side-hinged window that swings out from the left or right with crank-out hardware.

Check Rail

The horizontal portion of a double hung window where the top and bottom sash meet. Simulated check rails use bars to simulate the look of a double hung window in a casement or glider.


Moisture that forms on a surface. This could be a result of a difference in temperature between the surface and the air, or high humidity in the home.

Cottage Window

A window with unequal sash, top and bottom. Bottom sash is larger than top sash.

Daylight Opening (DLO)

The area of the window or door where light passes through; the width and the height of the visible glass.

Decorative Glass

Glass formed by running molten glass through special rollers. These rollers have a pattern on them causing the glass to become patterned and obscure to create the perfect combination of style and privacy.

Direct Glaze

Stationary or fixed window with no sash for maximum daylight opening. The glass is glazed directly into the frame. Infinity roundtops and polygons are direct glazed.

Divided Lites

Decorative bars permanently adhered to glass (Simulated Divided Lites) or between two panes of glass (Grilles Between Glass) to add architectural interest on a window or door.

Double Hung

Double hung windows have two movable sash (top and bottom) which are hung in the window frame and slide/operate vertically.


Used to describe a 3-wide picture unit or bay.


Optional locking device that locks to the sill on the Sliding French or Sliding Patio door. Keep door slightly opened and locked for ventilation or shut door and lock for added security.


The stationary portion of a window that surrounds either the glass (direct glaze) or the sash (operating or stationary). There are three components to the frame: the header across the top, the jambs down each side and the sill across the bottom.

French Door

A style of door that have wider stiles and rails for a more traditional look on either sliding or swinging doors.

Full-Frame Replacement

Existing windows are completely removed down to the studs and the new window is installed in the opening.


Installing glass into a window or door


Horizontal operating units which have one sash fixed while the other glides open left or right.

Grilles Between the Glass (GBGs)

Dividers placed between the panes of insulated glass to simulated authentic divided lites. GBGs allow for easier window cleaning with no bars on the exterior or interior surface of the glass.


A term used to describe the right or left hand operation of a window or door.


The locks, crank handles and hinges on windows and doors used to operate and secure them.

Head Jamb

The horizontal piece forming the top of the frame on a window or door.


A locking rod device installed vertically in the stile or astragal of a door or screen which when activated secures the door in a stationary position.

Inactive Panel

Fixed or non-operating portion of the door that holds the glass and is separate from the frame.

Insert Replacement

New windows are installed within the existing frame. Only the old sash, hardware and covers are removed and replaced.

Insulating Glass

Two panes of glass separated by a spacer and sealed tight.

Inswing French Door

An inswing French door has panels that open inward, allowing more space outside while providing optimal fresh air flow. Inswing French doors may be ideal for homes with limited exterior space or where an outswing door would interfere with landscaping or seasonality factors, such as snow in the winter.

Interior Casing

The casing trim used on the interior perimeter of the window or door. Generally supplied by others except in the case of round top casing which is factory supplied.

Jamb Extension

A jamb-like member, usually surfaced on four sides, which increases or extends the depth of the exterior or interior window or door frame.

Keyed Cylinder Lock

A lock providing an exterior entry and locking convenience.

Laminated Glass

Even more durable than tempered glass, laminated glass is often referred to as impact resistant or safety glass as it tends to remain in place when cracked.

Low E Glass

Extremely thin coating of special low emissivity (low E) metallic material are applied to glass pane to boost energy efficiency and block out UV rays.

Masonry Opening

A brick, stone or block opening into which a window or door unit is installed including the outside casing.


Mull: the actual components used to attach two or more windows and/or door units together to form an assembly.
Mulling: the process of attaching two or more window or door units together.


The vertical member of a sash, window or door frame between openings in a multiple opening frame.

Multi-Point Locking System

Multiple point locking mechanisms installed on Swinging French Door and Casement window.


Bars that form the decorative grille pattern on a window or door.


A moving sash, panel, or unit

Oriel Window

A window with unequal sash, top and bottom. Bottom sash is smaller than the top sash.

Outswing French Door

An outswing French door has panels that open outward, creating more room inside. Outswing French doors may be ideal for homes with spacious exterior space or where an inswing door would interrupt interior design or furniture layout. The outswing French door may be ideal in warmer climates where snow isn’t a concern with doors opening to the exterior.


The letters OX or XO identify the operation of window or door units as viewed from the exterior. The letter O stands for stationary while the letter X stands for operating.


Stationary or operating portion of the door that holds the glass and is separate from the frame.

Picture Window

A fixed/stationary window to align with the profiles of operating windows. Sash is non-operable and attached directly to the frame. Often available in significantly larger sizes than accompanying operating windows.


Windows that are direct glazed in various shapes such as triangles, rectangles trapezoids, pentagons, hexagons, and octagons.


The process Marvin uses to create Ultrex fiberglass by pulling strong cables of glass saturated with specially compounded resins through a machine to create various window and door profiles.


The resistance a material has to heat flow. Higher numbers indicate greater insulating capabilities.


The length of an imaginary line from the center point of a circle to the arc or circumference of a circle.


The horizontal part of a sash, door panel, or screen.


A term used to describe the steel drive worm, gears and crank device used for opening awnings and casements.

Rough Opening

The opening in the wall where a window or door unit is to be installed. Openings are larger than the size of the unit to allow room for insulation.

Round Top

An arched window that is directly glazed to the frame. Add visual interest to a room and natural light.


The operating and/or stationary portion of the window that holds the glass and is separate from the frame.

Sash Lock

A locking device which holds a window shut, such as a lock at the check rails of a double hung unit. Larger units utilize two locks.


A close-mesh woven screen material of metal or fiberglass attached to an aluminum or wood surround. Screens inhibit entry of insects, yet allow for light, air and unobstructed views.

Side Jamb

The left and right vertical pieces forming the frame on a window or door.


The lower, horizontal piece of a window or exterior door frame that supports the frame.

Simulated Divided Lites (SDLs)

Permanently adhered in our factory to the outside surfaces of the glass. SDLs have a spacer bar between the panes of glass to offer the traditional look of divided lites.

Single Hung

Looks like a double hung, but only the bottom sash moves up and down.

Sliding French Door

A French-style patio door available in two, three or four-panel configurations. Left, right and/or center panels operate when grouped in three. When grouped in four, two center panels slide out to the side to reveal a wide walk-through center opening.

Sliding Patio Door

A sliding door featuring a narrow profile for a more contemporary styling and increased daylight opening. Available in configurations similar to the Sliding French Door.

Solar Heat Gain (SHGC)

The Solar Heat Gain Coefficient (SHGC) measures how much heat from the sun enters your home. The lower the number, the less heat the window lets in. You’ll want a lower SHGC if you have high cooling costs in the summer; a higher SHGC can help warm a home in a colder climate during the winter.


Used to separate the two pieces of glass in an insulating glass panel.


A non-operating sash, panel or unit.


The upright or vertical members of the framework of a sash, door, screen or other panel assembly

Swinging French Door

A swinging French door features glass panels with wider top and bottom rails for a more traditional look. Swinging French doors can be either inswing or outswing, depending on your design preferences and available space. Swinging French doors provide optimal fresh air flow.

Tempered Glass

Increases glass strength to help prevent breakage. This option is ideal for windows that are close to the floor or located in high-traffic areas.


U-factor measures how well a window keeps heat inside your home. A higher number allows more heat to escape; a lower number allows less heat to escape. If you live in a colder climate, you’ll want to look for a low U-factor.


A pultruded composite material made of resin and glass fibers with an integrated proprietary finish. This superior material is used in Infinity products.


One single window or door.

Visible Transmittance (VT)

Measures the amount of visible light that passes through a window. A high VT maximizes daylight.


A strip of resilient material designed to seal the window or door in order to reduce air and water infiltration.


The letters OX or XO identify the operation of window or door units as viewed from the exterior. The letter O stands for stationary, while the letter X stands for operating.