For Homeowners > Glossary

 

Apron:
Inside trim applied to the wall under the window stool cap (sill).
Arch-Top:
A door or window with a radius top door panel and matching radius frame.
Architectural Specialty Window:
A general term used to describe any number of differently shaped windows. Includes circle tops, eyebrow, arch-tops and geometric shapes such as pentagons, trapezoids and circles. Most shapes are only available as fixed windows, but some are available venting.
Argon Gas:
Refers to a colorless, odorless gas used to fill the airspace between the panes of insulating glass. Argon gas increases the thermal performance of the glass by minimizing the transfer of heat in or out. Argon gas is usually coupled with a Low-E coating to maximize the energy efficiency of glass.
Astragal:
The center molding in a double door setup which covers the gap in the middle of the doors.
Authentic Divided Lite (ADL) or True Divided Lite (TDL):
Single or insulating glass as true individual panes in a particular pattern.
Awning:
A window that cranks out from the bottom and hinges on the top.
Backset:
The distance from the edge of the door to the center of the lock bore.
Baluster:
The upright support for the handrail on a staircase. Wood pin top balusters have turned, round tops. Wood square top balusters require plowed handrail and fillet (filler for the plowed handrail). Balusters come in wood or wrought iron.
Bay:
A multiple assembly of windows made from casements or double-hungs and/or picture windows. Bay windows come in a 30, 45 or 90-degree angle, projecting out from the wall of the house.
Bifold:
A door that hinges in the middle and stacks to either side of a door opening. Usually used in closet openings. Available in wood, molded and mirror.
Bore:
The hole milled in a door to accept the knob or dead bolt; usually a cylindrical hole.
Boxed Unit:
A replacement window that comes inside it's own thin frame. Also called an insert window.
Bow:
A multiple assembly of casement windows, arched to create an average 10-degree angle projecting out from the house.
Bypass:
A door unit whose panels hang on a track at the top of the door opening and slide back and forth. Usually used in closet openings. Available in wood, molded and mirror.
Caming:
Decorative metal grid work that replicates leaded or stained glass in a door.
Casement:
A window that cranks out from the bottom and hinges on either side.
Casing:
Trim on the inside or outside of the window. Examples include colonial, flat and brickmould casing.
Checkrail:
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.
Cladding:
The exterior covering on the window. Cladding materials include aluminum and vinyl.
Colonial Door:
A door with raised panels.
Cross or Lock Rail:
The center horizontal member of a door.
Cupola:
A small, decorative wooden structure on top of a building; most often has a copper roof and weathervane.
Deadbolt:
The metal bolt which slides from the door into the frame to prevent the door from opening. An extra security feature for doors. Can be keyed on both sides, or have a thumb-turn on the inside.
Design Pressure (DP):
Indicates the amount of pressure (in pounds per square foot) a window or door is designed to withstand when closed and locked. The higher the DP, the better the performance. The Design Pressure rating was created by the American Architectural Manufacturer’s Association (AAMA)/Window and Door Manufacturer’s Association (WDMA).
Distressed:
Refers to a hardware finish with an aged or antiqued appearance.
Divided Lites:
Real, or the look of real, individual panes of glass.
Double Hung-Cottage Style:
A double-hung window that has a smaller top sash than bottom sash, or vice-versa.
Double Hung:
A window with two sashes that slide up and down.
Dummy:
A knob or lever on a door that is applied to the face of the door and has no latch. 
Edge Pull:
A door pull mortised into the edge of a door, usually a pocket door.
Egress Window:
A window large enough to provide egress, or exit, in case of emergency. Egress requirements are outlined in local building codes.
Extension Jamb:
Wood molding pieces that apply to the inside edges of a window frame to extend its width to match the thickness of the wall.
Fenestration:
Refers to the arrangement of windows in a wall.
Flush Bolts:
The head and foot-bolts that secure the passive door in a pair of doors. The flush bolts are usually used in conjunction with an astragal.
Flush Door:
A door with no panels and just a smooth face.
Frame Size:
The tip-to-tip size of the unit. Sometimes called the “make size” on a vinyl replacement window.
French Door:
A door with glass divided lites, usually 10 or 15.
Gable End Louver:
A small louver installed on the sides at the top level of a house to help vent the attic. Available in square, triangular, round, and half round shapes.
Glazing Bead:
A plastic or wood strip applied to the window sash around the perimeter of the glass.
Glazing:
The glass of a window. Single glazing=1 sheet of glass. Insulated glazing=Two sheets of glass, sealed with space between the sheets of glass.
Glider:
A window with a horizontally gliding sash.
Green Building:
According to the EPA, “the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building’s life-cycle from siting to design, construction, operation, maintenance, renovation, and deconstruction…Green building is also known as a sustainable or high performance building.”
Grille Between Glass (GBG):
Aluminum flat or contoured bars installed between the panes of an insulating glass window.
Grille:
Removable wood muntins installed against the glass on the interior to give the look of Authentic Divided Lites.
Handing:
Refers to which way the door swings. A left-hand door pulls toward you with the knob on the left; a right-hand door pulls toward you with the knob on the right.
Header:
The top of a window frame.
Hinge:
A jointed device on which a door swings.
Hopper Window:
Most popular in basements, a rectangular window that hinges on the top or bottom and pulls into the house.
Impact Resistant Glass:
Single or double pane glass using one or more laminating glass layers.
Inswing:
Refers to an exterior door that swings into the house.
Jack Stud:
Framing members that form the inside of the window or door rough opening.
Jamb Liner:
A metal or plastic track, covering the sides of a double-hung window frame, on which the sashes run up and down.
Jamb:
The left and right vertical sides of a window or door frame. Available in different widths depending on the total wall thickness of the house or other building.
Lite:
A single area of glass within the window sash or a pattern of divided lites.
Low-E Glass:
Low-E (“low emissivity”) refers to a microscopic metallic coating on glass which improves its thermal performance. Simply put, Low-E glass keeps the intense heat out during the summer months, and helps preserve the heat inside during the colder months. Low-E glass also reduces damage from UV (ultraviolet) rays.
Magnetic Catch:
A cupboard catch that uses a magnet to hold the door closed.
Masonry Opening:
The opening in a masonry wall to receive a window or door unit.
MDF:
Medium Density Fiberboard is an engineered wood product, made up of compressed wood fibers and some type of wax or resin.
Molded Door:
An interior door with various panel designs made from a compressed particleboard core and either a smooth or wood grain fiberboard skin.
Molding:
Another term for trim or casing. (Alternative spelling: moulding)
Mortise and Tenon Joint:
A type of joint used to join two pieces of wood together, such as in a window frame. A mortise, or hole is cut in one piece wood and a tenon, or projection, in the other piece of wood is inserted in the mortise to produce a strong joint.
Mortise Lock:
A type of lock which has a rectangular lock box as part of the hardware assembly. Installs in the core of the door. Requires a special prep in the door.
Mulling:
Refers to the act of attaching two or more window units together. A mullion refers to the vertical or horizontal joint between joined windows.
Multiple Assemblies:
Sometimes called a “mulled” unit. Windows are connected to create a single unit, allowing for limitless possibilities.
Multipoint Lock:
A type of lock which has bolts that lock into the center as well as the upper and/or lower jamb.
Muntins:
The bars that divide glass into lites.
New Construction Windows:
New construction windows generally come with a nail flange and are installed in a rough stud opening.
Newel:
The posts at the top, bottom and at various points on a staircase
NFRC:
The National Fenestration Rating Council—a non-profit organization which provides independent, accurate energy performance ratings for windows and doors.
Operator:
The crank hardware for a casement or awning window.
Outswing:
Refers to an exterior door that swings out of the house.
Over-the-Post:
Stairways that have a continuous handrail set on top of the newels and balusters.
Passage Function:
A knob or lever set that does not lock. Most frequently used on interior and closet doors.
Picture Window:
A fixed window that does not open.
Pocket Door:
A door that slides into the wall, as opposed to swinging into a room.
Post-to-Post:
Stairways that have a handrail that connects into the upper part of the newel.
Pre-Hung Door:
A door set up in a frame with or without casing applied.
Privacy Function:
A knob or lever set that locks from inside the room, such as a bedroom or bathroom. Has an emergency release feature on the outside.
PVD:
Short for “Physical Vapor Deposition”: This refers to a process for coating finishes on hardware. A PVD finish is very evenly coated, resistant to breakdown, and exhibits a shiny, durable, long-lasting finish, unlike simple lacquer coating.
R-Value:
Indicates the resistance a material has to heat flow. The higher the R-Value, the greater the insulating capabilities of the unit.
Rails, window:
The horizontal sides of the sash.
Rails, door:
The horizontal top and bottom members of a panel door.
Replacement Window:
A new window designed to fit inside existing window opening frame, so as not to disturb the inside and outside trim and siding. Replacement windows are available as boxed units or sash kits. Styles include double hung, basement, and casement replacement windows.
Riser:
The front facing of each step on a staircase.
Roof Window:
An operable roof window that opens manually or electrically.
Rosette, moulding:
A small, square decorative molding piece that often goes in the corners of window and door trim. Most popular in a “bullseye” pattern.
Rosette, hardware:
The back-plate, often decorative, of a knob or lever.
Rough Opening:
The opening in a wall to receive a window or door unit. The rough opening should leave room for shimming the unit to make sure it is plumb, level, and square.
Sash Balance:
A system of weights, cords and/or coiled springs, which assist in raising double-hung sash and keeping them in place.
Sash Kit:
A replacement window with separate window sashes and tracks for the sides of the existing frame.
Sash Lock:
The lock on the sash.
Sash:
The glass and wood operating or stationary portion of a window installed into the frame of the window. The sash consists of stiles (the vertical sides of the sash) and rails (the horizontal sides of the sash).
Shaker Door:
A door with flat panels and either square or no sticking.
SHGC:
Solar Heat Gain Coefficient is a measure of how well a product blocks heat from the sun. The lower the SHGC, the less solar heat is transmitted and the greater the product’s shading ability.
Shims:
Wood, plastic or composite wedges used to make a window or door square, level and plumb in a rough or masonry opening.
Sidelights:
Fixed door panels, usually with glass, that go on either side of a door to create an entrance unit.
Sill:
The bottom of a window frame.
Simulated Divided Lite (SDL):
Muntins permanently fixed to the inside and outside of the glass, with or without a spacer bar. Meant to give the appearance of individual panes.
Single Hung:
A window with a stationary top sash; the bottom sash slides up and down.
Skylight:
A fixed roof window, usually flat, but also available as bubbles, pyramids and other shapes.
Spacer Bar:
Aluminum bars inserted between Simulated Divided Lite muntins to give the look of true individual panes.
Stairway components:
Include caps, volutes, turnouts, starting easings and rosettes.
Starting Step:
The first step of a staircase, which includes a finished front.
Sticking:
The small moulding around the perimeter of a door panel. Examples include ogee, ovolo and shaker.
Stiles:
The vertical (side) members of a panel door.
Stiles:
The vertical sides of the sash.
Stool Cap:
Another term for inside window sill.
Storm Door:
An aluminum or wood exterior door that installs outside the main door to provide ventilation and offer protection from harsh weather. Most storm doors come with an interchangeable storm/screen option.
Tempered Glass:
Safety glass which breaks into small beads, instead of shattering into dangerous shards. Often used in bathrooms, or when a window is close to the floor. Doors automatically come with tempered glass.
Transom:
A window, usually a rectangle, that goes over the top of another window.
Tread:
The stair steps. Available in oak, pine, maple and other species of wood.
True Divided Lite (TDL) or Authentic Divided Lite (ADL):
Single or insulating glass as true individual panes.
U-Factor:
Measures heat transmission through a wall, window or door. The lower the U-Factor, the better the insulating value.
Vapor Barrier:
A watertight material used to prevent the passage of moisture into or through floors, walls and ceilings.
VOC:
“Volatile Organic Compound” (or VOC) refers to organic compounds that can have chronic negative health effects. Examples would be solvents such as acetone and formaldehyde found in some paints and building products. Low VOC products are an important component of Green building practices.
Weatherstripping:
The rubber, metal or plastic gasketing around a door to seal out water, drafts and debris. A door bottom is the weatherstripping on the bottom of a door.