Window and Door Glossary of Terms

Have you ever been confused when talking to a window and door contractor? Window and door terms can be confusing to average homeowners, so we hope this page is a good resource!

Window & Door Terminology

Awning windows: a type of window that operates by pivoting outward on hinges set on the top.

Bay windows: a window style that protrudes out from the wall and extends beyond the foundation. Most bay windows have three sashes and project out at 30 or 45 degrees.

Bow windows: also called compass or radial bay windows, these rounded windows project from the wall in an arch shape. They usually consist of five sashes.

Box bay windows: a window style that protrudes out from the wall and extends beyond the foundation at a 90-degree angle.

Casement windows: a type of window that operates by pivoting outward on hinges set on one side. Casements can open on the left or right, inward or outward.

Bottom rail: bottom horizontal part of a window sash

Casing or trim: exposed molding or framing around a window or door that covers the space between the frame and wall

Caulk: rubber based material used to seal cracks and fill joints to prevent water and air leakage

Coated glass: glass with a reflective exterior surface; can help protect you from UV rays

Composite windows: a type of window made from several different materials combined together. The window benefits from having multiple materials rolled into one.

Double hung windows: a type of window that operates by sliding up and down. Both the upper and lower sashes are operable. Read more here.

Drip cap: horizontal molding used to divert water from the top casing so that it drips beyond the outside of the frame; this can prevent water damage

Fenestration: the design and placement of window openings in a home or building

Fiberglass windows: a type of window where the frame and sash are made of fiberglass. High strength, durability, and performance make this a good choice for many homeowners.

Fixed window: type of window that doesn’t open

Folding door system: a type of exterior door with multiple panels that are hinged to pivot and fold together when opened. Folding doors may include anywhere from two to four or more panels.

Forced-entry resistance (FER): the ability of a door or window to resist entry from the outside while in the locked position.

Garden windows: a window style that protrudes out from the wall to provide a ledge to set small plants and herbs, often installed above kitchen sinks.

Geometric windows: a unique window shape designed to add aesthetic appeal to a home. Geometric windows don’t operate.

Hinge: a moveable joint that allows a window to swing open

Hopper light: inward opening sash that is hinged at the bottom

Integrated door: a type of exterior door that comes with all working hardware and the door integrated into a single package. Centor is a popular manufacturer of integrated doors.

Jamb depth: width of the window frame from the inside to the outside

Jambs: the vertical components of a window or door frame.

Lite: a pane of glass used in a window, door, or skylight.

Moisture barrier: a material that protects your windows and doors from water damage; polyethylene is often used

Mullion: a thick bar separating adjoining windows set into the same frame.

Muntin: a thin grille separating a window lite into smaller sections.

Orientation: placement of windows in regard to access, view, sun, etc.

Pane: a sheet of glass for glazing a window

Passivehaus: a European energy trend originating in Germany and Norway. Promotes energy-efficiency in homes as well as renewable sources of energy to make your home more environmentally-friendly.

Picture windows: a large window doesn’t operate. It provides natural light and a view of the exterior, but no ventilation.

PVC: a molded plastic material used for window frames and as a thermal barrier for aluminum windows

Reflective glass: type of glass that reflects the sun’s rays

R-value: measure of resistance to heat flow; the higher the value, the better the heat insulating properties

Sash: framework in which the pane of a window is set

Side lite: the name for a lite installed on one or both sides of a door.

Single hung window: a type of window that operates by sliding up and down. Only the lower sash is operable.

Sliding door: a type of exterior door that opens by sliding to the left or right. Sliding doors are comprised primarily of glass.

Sliding windows: a type of window that operates by sliding horizontally. One or both sashes may operate.

Transom: a window installed above an interior or exterior door. Read more here.

U-value: the rate of heat flow through a building (difference between the indoor and outdoor air temperature)

Vinyl Windows: type of window where the frame and sash are created out of vinyl. Great choice for buyers looking for an efficient and cost-effective window material.

Venting windows: a unique type of picture window that opens evenly on all sides by just an inch or two to allow for passive air exchange.

Weatherstrip: flexible material used to cover the joint of a window between the sash and frame; helps reduce air and water intrusion

Weephole: small holes in the bottom edge of the storm sash to allow rain to wash away from the sill to the outside; helps prevent water damage

Heard a term that isn’t on this list? Want to learn more about these window and door terms? Contact Gulf Coast Windows & Doors today!