Definitions- Learn the Basics

A-C

Astragal
The center member of a double door, which is attached to the fixed or inactive door panel.

Awning Window
A window that has a single sash in which the bottom of the sash swings outward. Awnings are typically wider than they are tall.

Bay Window
A composite of three windows usually made up of a large center unit and two flanking units, typically they are 30 or 45 degree angles to the wall. A bay window refers to the angle of departure from the plane of a wall.

Between-The-Glass Window Fashions
Blinds, fabric shades and grilles tucked between panes glass. Protected from dust and damage.

Bottom-Up Shades or Blinds
A standard operating shade or blind that can be raised and lowered to any position.

Bow Window
A composite of four or more window units in a radial formation. Typically at a 12 or 14 degree angle to the wall.

Brickmold
Exterior casing around a wood window or door through which nails are driven to install the unit. Covers the gap between the frame and masonry opening. In some cases, siding is installed up to the edge of the brickmold.

Casement Window
A window unit in which the single sash is either fixed or opens outward to the left or right. Casements are generally taller than they are wide.

Casing
Exposed molding or framing around a window or door, on either the inside or outside, to cover the space between the window frame or jamb and the wall.

Check Rail
The bottom rail of the upper sash and the upper rail of the lower sash on a double or single-hung window where the lock is mounted which meet when closing. Also known as Meeting Rail and Lock Rail.

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. Also known as Round Top or Half Round.

Cladding
An aluminum material bonded to the exterior faces of Dunn Wright wood products.

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

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


D-F

Design Pressure
The pressure a product is designed to withstand. This value is a measure of a product’s capacity to withstand the forces of windloading, in both positive and negative directions, while it is closed and locked.

Dormer
A projection through the slope of a roof for a vertical window.

Double-Hung Window
A window unit that has two operable sashes which move vertically in the frame. A counterbalance mechanism usually holds the sash open or closed.

Drip Cap
Horizontal molding to divert water from the top of a window unit so water drips beyond the outside of the frame. May be metal or wood.

Dual Durometer
A material that has two or more levels of flexibility. An example is the weatherstripping used between the frame and sash of Dunn Wright casement window.

EnduraHardware™
Dunn Wright's collection of hardware that offers superior corrosion resistance and is backed by a 10-year warranty.

ENERGY STAR®
A government-backed program helping businesses and individuals protect the environment through the use of high-efficiency products. ENERGY STAR® qualifying products, such as windows and doors, mean these items use less energy, save money and help protect the environment.

Extrusion
A form produced by forcing material through a die. Dunn Wright uses aluminum extrusion on the exterior of the frame on clad wood units.

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

Fixed
Non-venting or non-operable.

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

Foam Spacer
Foam material placed in the airspace of the insulating glass in Dunn Wright windows or doors to give it the look of true divided light (TDL). See Integral Light Technology.

Frame
The combination of head, jambs and sill to form a precise opening in which a window sash or door panel fits.

French hinged door
A hinged door normally with wider stiles and rails but having glass panes constituting all or nearly all of its surface area.

French sliding door
A sliding patio door, which has more substantial (wider) panel frame members giving it the look of French hinged doors.
G-I

Glazing
The process of applying or installing glass into a window sash or door panel. Also refers to the type of glass used in the process.

Glazing Stop
A molding around the interior or exterior of a window sash or door panels holding the glass in place. Also called a glass stop.

Grille (Grilles)
Wood, plastic or metal dividers, (grilles, grids, bars) designed for a single light sash or panel to give the appearance of muntins in as multi-light sash or panel. These can be removable or fixed. Also called Muntins.

Grilles-Between-The-Glass (GBG)
Grilles are permanently installed between the panes of the insulating glass.

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 or door to prevent the weight of wall or roof from resting on the window frame.

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

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.

Integral Light Technology™
The technology developed by Dunn Wright which incorporates a foam grid between the panes of insulating glass. Muntins (grilles) are then permanently bonded to the interior and exterior pieces of glass. Provides the look of True Divided Light with the performance of insulating glass.
J-L

Jamb
The main vertical members forming the sides of a window or door frame.

Jamb Liner
The track in single hung and double hung window frame jambs on which the sashes slide.

Knocked Down (KD)
An unassembled window or door unit.
M-O

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 part and a matching projecting tenon in the other. Used as a corner joint in Dunn Wright sashes.

Mullion
A wood, metal or vinyl 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.

Muntin Bar
Any small bar that divides window or door glass. Also called a grille or windowpane divider.
P-R

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

Pane
A framed sheet of glass within a window or door frame.

Panel
Usually refers to the separate panel or panels in a door frame. A panel may be operable or stationary.

Parting Stop
A narrow strip, either integral or applied, that olds a sash or panel in position in a window or door frame.

Precision Fit® Double-Hung Window
A fully assembled double-hung that slides easily into the existing sash pocket of your old double-hung with no damage to wallpaper, paint or plaster. For use in replacement applications only.

Rail The horizontal top and bottom members of a window sash or door panel.

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. It is the inverse of the U-Value (R=1/U).
S-U

Sash
A single assembly of stiles and rails made into a frame for holding glass.

Sash cord
The rope or chain which attaches to the sash and the balance system of a single-hung or double-hung window.

Sash lift A handle used to assist in raising and lowering the sash of a single-hung or double-hung window.

Sidelights
A fixed frame of glass beside a window or door.

Sill
The main horizontal member forming the bottom of the frame of a window or door.

Simulated Divided Light
Grilles permanently bonded to the interior and exterior of the insulating glass simulating a divided light appearance.

Single Gslazing
Single thickness of glass in a window or door.

Single-Hung A double-hung type of window in which the top sash is fixed or inoperable.

Sliding Patio Door
Patio door in which a vent panel moves horizontally on a track system past a fixed panel.

Slimshade® Blinds
Dunn Wright exclusive blinds positioned between the exterior and interior glass panel. Available on Designer Series products in tilt-only and cordless raise and lower configurations.

Solar Heat Gain Coefficient (SHGC)
A measure of how effective a window or door is at keeping out solar heat. It is calculated by taking the amount of solar heat that enters a room through a window or door (center glass), divided by the amount that is actually contacting the exterior of the unit. The lower the value, the better the unit keeps out solar heat.

Sound Transmission Class (STC) Rating
Measures the amount of noise reduction that can be achieved with a given product. A noise reduction of 10 decibels represents cutting the noise level in half, as interpreted by the human ear. So a rating of 25 means that the product reduces the outside noise by approximately 25 decibels, cutting the noise in half 2-1/2 times, or cutting it by over 80 percent.

Stile
The vertical members of a window sash or door panel.

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.

SureLock® System
Dunn Wright's patented unison locking system on casements which secures the window at two locking points by operation of one handle. Locks reach out to lift and pull the sash against the weatherstripping to form a tight seal. Standard on all casement windows over 29" tall.

Tempered Glass
Glass manufactured to withstand greater than normal forces on it surface. It is approximately five times stronger than annealed glass. When it breaks, it shatters into small pieces to reduce hazard. Tempered glass can not be cut after tempering.

Tenon
A rectangular projection cut out of a piece of wood for insertion into a mortise.

Thermal Break
An element of low conductance placed between elements of higher conductance to reduce the flow of heat (or cold). Often used in non-wood windows.

Tilt-Only Blinds
Blinds are fixed at the top and bottom of the window and tilt for light control.

Top-Down Shades
When extra privacy is desired, choose a top-down shade -- shade is only adjustable from the top, allowing light to come through the top of the window.

Transom
A small window that fits over the top of a door or window, primarily for additional light and aesthetic value.

U-value
The rate of heat transfer through a window, door or skylight (center-glass). The lower the U-value, the better the insulating properties of the unit or glazing system.
V-Z

Vent Panel
The panel that moves horizontally on a sliding patio door.

Vent Unit
A window unit that opens and closes.

Weatherstrip
A material of device used to seal the openings, gaps or cracks of venting windows and doors to minimize water and air infiltration.

Windload The pressure, positive or negative, acting on an external surface of a building caused by the direct action of the wind.