Windows & Doors
WINDOWS AND DOORS
Astragal
The center member of a double door, which is attached to the fixed or inactive door panel.
Awning window
A window unit in which the bottom of the sash swings outward.
Bay window
A composite of three windows, usually made up of a large center unit and two flanking units at 60- or 45-degree angles to the wall.
Bow window
A composite of four or more window units in a radial or bow formation.
Brickmold
A type of external casing which frames windows and doors.
Casement window
A window unit in which the single sash levers outward, to the right or left.
Casing
Molding of various widths, thickness and shapes applied to the framework of window and door units.
Circlehead
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.
Cladding
An aluminum material locked to the outside faces of many Pella® products to provide a durable, low-maintenance exterior surface.
Clerestory window
A venting or fixed window above other windows or doors on an upper outside wall of a room.
Dormer
A space which protrudes from the roof of a house, usually including one or more windows.
Double glazing (STANDARD FEATURE)
Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits.
Drip cap
A molding placed on the top of the head brickmold or casing of a window frame.
Double Weatherstripping
A material that has two or more levels of flexibility. An example is the weatherstripping used between the frame and sash of a Pella casement window.
Extrusion
A form produced by forcing material through a die. Pella window frames are clad with extruded aluminum.
Fixed
Non-venting or non-operable.
Flashing
A thin strip of metal or synthetic material that diverts water away from a window or skylight.
Foam Spacer
Foam material placed in the airspace of the insulating glass in windows to enhance the appearance and improve the performance of the window.
Frame
The enclosure in which window sash or door panels are mounted.
French hinged door
Hinged door(s) which have wider panel members around the glass.
Glazing
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.
Grille
A term referring to windowpane dividers or muntins, usually a type of assembly which may be detached for cleaning.
Head
The main horizontal member forming the top of the window or door frame.
Header
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.
Hopper
A window unit in which the top of the sash swings inward.
Insulating glass (IG) (STANDARD FEATURE)
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.
Jamb
The main vertical members forming the sides of a window or door frame.
Jamb liner
In a modern double-hung window, the track installed inside the jambs on which the window sashes slide.
Knocked down (KD)
Unassembled window or door unit.
Light
A separately framed piece of glass in a window or door. A traditional double-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 indicate the number of lights in each sash. Sometimes spelled ‘lite.’
Low-emissivity (low-E) glass
A special type of glass having a transparent material fused into its surface which acts as a thermal mirror.
Masonry opening
The space in a masonry wall left open for windows or door.
Mortise
A slot or rectangular cavity cut into a piece of wood to receive another part.
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. Used as a corner joint in Pella sashes.
Mullion
A wood or metal part used to structurally join two window or door units.
Muntin
Applies to 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.
Panel
Usually refers to the separate panel or panels in a door frame.
Rail
The top and bottom horizontal members of the framework of a window sash.
Rough opening
The framed opening in a wall into which a window or door unit is to be installed.
R-Value
Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.
Sash
A single assembly of stiles and rails made into a frame for holding glass.
Sash lift
A protruding handle screwed to the inside bottom rail of the lower sash on a double-hung window. Available on all Pella double-hung windows.
Sash weights
In older double-hung windows, the concealed cast-iron weights which are used to counterbalance the sash.
Sidelights
Narrow fixed units mulled or joined to door units to give a more open appearance.
Sill
The main horizontal member forming the bottom of the frame of a window or door.
Simulated divided light
A method of constructing windows in which muntins are affixed to the inside and outside of a panel of insulating glass to simulate the look of true divided light. These windows use gray foam spacers between the exterior and interior muntins to enhance the authentic look. Other brands of windows use shiny metal spacers or no spacers at all, resulting in a look that is less authentic.
Single glazing
Use of single panes of glass in a window. Not as energy-efficient as double glazing.
Single-hung
A double-hung type of window in which the top sash is fixed or inoperable.
Stile
The main vertical members of the framework of a sash.
Stool
An interior trim piece on a window which extends the sill and acts as a narrow shelf.
Stop
A molding used to hold, position or separate window parts.
Tempered glass (STANDARD)
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 H&H doors.
Tenon
A rectangular projection cut out of a piece of wood for insertion into a mortise.
Thermal break
The addition of a thermal insulating material between two thermally conductive materials.
Transom
A small window that fits over the top of a door or window, primarily for additional light and aesthetic value.
True divided light
A term which refers to windows in which multiple individual panes of glass or lights are assembled in the sash using muntins.
Vent Unit
A window or door unit that opens or operates.
Vinyl
A plastic material used by some window manufacturers.
Weatherstripping
A material or device used to seal the openings, gaps or cracks of venting window and door units to prevent water and air infiltration.
Windload
Force exerted on a surface by moving air.
Windowpane divider
See muntin.
