Windows and Doors Glossary

With this Windows and Doors Glossary, transforming your space with new windows or doors from Windows Canada is easier than ever. Our team is committed to providing clarity and confidence in your choices, so we’ve crafted this comprehensive guide to demystify industry terms and streamline your decision-making. Browse the glossary below to find everything you need to make informed, straightforward choices for a more beautiful and energy-efficient home. And if you have questions, we’re here to help every step of the way!

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A

  • Air Infiltration – The passage of air through the seals of windows or doors, often due to poor insulation.
  • Annealed Glass – Standard glass is cooled slowly to reduce internal stress; it is less durable than tempered glass.
  • Argon Gas – An inert gas placed between glass panes to improve thermal efficiency and reduce energy loss.
  • Arched Window – A rounded top window typically used for decorative purposes in traditional architecture.
  • Awning Window — A window hinged at the top opens outward to create an awning effect, which is ideal for ventilation during rain.
  • Aluminum Clad WindowA window with a wood interior and an exterior covered (or "clad") with aluminum offers the warmth of natural wood indoors and the durability of aluminum outdoors.
  • Aluminum Window – A window frame made from aluminum, known for its strength, durability, and low maintenance.
  • Awning Window – A window hinged at the top that opens outward to create an awning effect, ideal for ventilation during rain.
  • Arched Doors – Adds a classic and elegant look, often used in Mediterranean or traditional styles, typically with wood or iron construction.
  • Accordion Doors – Doors that fold to save space ideal for closets or partitions.

B

  • Bay Window – A window unit that protrudes outward from the main wall, creating additional space inside. It often has a fixed central window and two side windows.
  • Bow Window – Similar to a bay window but made with more panels, forming a rounded shape.
  • Bifold Window – A window that opens by folding back along a track, similar to a bi-fold door.
  • Brickmould – A trim around the window frame that helps secure the unit to the wall and offers weather protection.
  • Butt Joint – A method of joining two pieces of material at their edges, often used in window frame construction.
  • Butt Doors – Regular hinged doors with two leaves joined at the hinge, often used for commercial settings.
  • Bifold Doors – Doors with panels that fold in pairs, popular for closets and pantries.
  • Battened and Ledged Doors – Simple doors with horizontal battens and vertical ledges, commonly used in rustic settings.
  • Barn Doors – Sliding doors inspired by traditional barn aesthetics, often used indoors for a rustic look.
  • Bi-Fold Door – A multi-panel door that folds against itself when opened, commonly used for wide entrances.

C

  • Casement Window – A window with hinges on one side, allowing it to open outward like a door.
  • Cladding – A protective layer, typically aluminum or vinyl, covering the window or door frame to improve durability.
  • Clerestory Window – A high, narrow window placed above eye level allows light into a room while maintaining privacy.
  • Cottage Window – A window with a larger bottom sash and smaller top sash, which is standard in traditional-style homes.
  • Composite Window – A window made from a combination of materials, such as wood and plastic, to provide durability and aesthetic appeal.
  • Condensation Resistance – The ability of a window or door to resist moisture build-up on its surfaces.
  • Curtain Wall – A non-structural exterior wall, typically made of glass and aluminum, attached to the building structure.
  • Composite Doors – Made from a combination of materials (wood, steel, glass), offering durability and insulation.
  • Craftsman Doors – are known for their clean lines and simplicity. They often feature natural wood and glass panels inspired by the Arts and Crafts movement.
  • Cased Opening Doors – Doorways without a door, framed to appear decorative, often used to transition between rooms.
  • Corner Windows – Placed at the corner of a structure, offering a panoramic view

D

  • Daylighting – The practice of using windows to bring natural light into a building, reducing the need for artificial lighting.
  • Double Glazing – Windows with two panes of glass and an insulating layer between them, enhancing thermal efficiency.
  • Double-Hung Window – A window with two sashes that slide vertically, allowing ventilation from the top or bottom.
  • Dormer – A window that extends vertically from a sloped roof, adding light and space to upper floors.
  • Dormer Windows – Installed on sloped roofs, commonly used in attics.
  • Drip Cap – A small angled strip installed above windows or doors to direct water away from the frame.
  • Door – An entryway panel that allows access to and from a space, typically hinged or sliding
  • Door Frame – The structural frame surrounding a door provides support and stability.
  • Dutch Door – A type of door divided horizontally, allowing the top half to open independently from the bottom half, often used for ventilation.
  • Double Doors – These large doors make a grand statement and are often used in larger homes with wood, glass, or iron details options.

E

  • Egress Window – A window large enough for emergency escape, typically required in bedrooms and basements.
  • Eyebrow Window – A curved or arched window set into the slope of a roof, often used for architectural interest.
  • Energy Star® Rating – Certification that verifies products meet Canadian energy efficiency standards.
  • Extrusion – The process of shaping materials like aluminum or vinyl into specific profiles used for window and door frames.
  • Exterior Door – A door designed for entry points to the outside of a building, built for durability and security.

F

  • Fenestration – The arrangement of windows and doors on a building’s facade.
  • Flashing – Water-resistant material installed around windows and doors to prevent water penetration.
  • Foam Spacer – A material that separates glass panes, reducing heat transfer.
  • Fiberglass Window – A window with frames made from fibreglass, known for energy efficiency and resistance to warping
  • Fixed Window – A non-operable window for light and views rather than ventilation.
  • Fibreglass Doors – Versatile and durable, these doors can mimic wood or metal finishes and are excellent for energy efficiency and weather resistance.
  • Frameless Doors – Glass doors without visible frames, offering a minimalist, modern look.
  • French Door – A pair of hinged doors with glass panes running the length of each door, often opening onto patios or balconies.

G

  • Garden Window – A small bay window typically installed above a kitchen sink for growing plants indoors.
  • Gas Fill – filling the space between panes with gases like argon or krypton for insulation.
  • Glazing – Refers to the glass itself or the process of installing glass in a window or door frame.
  • Grilles – Decorative bars placed on or between panes to simulate divided glass, enhancing the aesthetic appeal.
  • Glazing Bead – A strip holding the glass within a window frame provides a finished look.
  • Glass Doors—These doors incorporate glass panels for a welcoming look, with options for full or partial glass panels. They are ideal for modern homes and are often paired with additional security features.

H

  • Head – The top horizontal part of a window or door frame.
  • Hinge  – A mechanical component that connects a door or window to its frame, allowing it to swing open or close along a fixed axis.
  • Hopper Window – A window that opens inward from the top, commonly used in basements.
  • Hybrid Window – A window constructed from a combination of materials, such as wood on the inside and aluminum on the outside.
  • Hurricane Window – Impact-resistant windows designed to withstand high winds and flying debris during storms. 
  • Hollow-Core Doors – Lightweight doors with a hollow interior, mostly used in interior applications for cost efficiency.
  • Louvered Doors – Doors with slats for ventilation, often used for closets or utility rooms.

I

  • Impact-Resistant Glass – Glass designed to withstand strong impacts, often used in storm-prone areas.
  • Insulated Glass Unit (IGU) – A sealed unit consisting of two or more panes of glass with a spacer, enhancing insulation.
  • In-Swing DoorA door that opens inward, commonly used in entryways.
  • Insulated Door – A door with an insulating core to enhance energy efficiency, often made from fiberglass or steel.

J

  • Jamb – The vertical parts of a window or door frame, which hold the sash or door in place.
  • Jamb Extension – An extension added to the jamb of a door or window to accommodate thicker wall constructions.
  • Jalousie Window – A window with multiple horizontal glass slats that tilt open for ventilation.

K

  • Krypton Gas – An inert gas used between glass panes to enhance insulation, especially in thinner windows.
  • Keyed Cylinder Lock – A lock mechanism that uses a cylinder with a keyhole on one side, requiring a key to engage or disengage the lock.
  • Keeper Rail – A structural part of a window or door frame that holds the locking mechanism in place, securing the sash or panel when closed.
  • Keeper Stile – The vertical section of a door or window sash where the locking mechanism, or "keeper," is mounted, allowing it to engage with the latch or locking component on the opposite stile.
  • Knee Wall – A short wall that supports a window, typically found in attics or lofts.

L

  • Laminated Glass is glass with a layer of plastic between panes, which adds durability and safety by holding shattered pieces together.
  • Lintel – A structural support above a window or door opening, bearing the weight of the wall above.
  • Low-E (Low-Emissivity) Glass – Glass with a coating that reduces heat transfer, maintaining indoor temperatures.
  • Lift and Slide Door – A sliding door that lifts slightly to allow for smooth opening and closing.
  • Louvered Windows – Similar to jalousie but often larger and used in tropical climates.

M

  • Mullion – A vertical or horizontal bar between window units, providing structural support.
  • Muntin – Strips of wood or metal dividing the glass into smaller panes within a window frame, typically decorative.
  • Multi-Slide Door – A door system with multiple sliding panels that can open wide to create a seamless indoor-outdoor transition.
  • Metal Doors – Doors made from steel or aluminum, typically used for security and industrial applications.

N

  • Nailing Fin – A thin strip that extends from the window frame is used to attach it securely to the wall structure.
  • NFRC Label – National Fenestration Rating Council label that details a window’s energy efficiency, including U-factor and SHGC.
  • New Construction Window – A window designed for installation in new buildings, typically featuring a nailing fin for easy attachment.

O

  • Obscure GlassFrosted or patterned glass that allows light while providing privacy, often used in bathrooms.
  • Obscure Glass – Frosted or patterned glass that allows light while providing privacy, often used in bathrooms.
  • Operable Window – A window that can open for ventilation, unlike fixed windows.
  • Oval Window – A window with an oval shape, often used for decorative purposes.

P

  • Pane – A single sheet of glass within a window or door frame.
  • Picture Window – A large fixed window that offers an unobstructed view.
  • Pivot Window – A window that rotates around a central axis, providing a unique opening mechanism.
  • Patio Window – A large window that provides access to an outdoor patio, typically sliding or hinged.
  • Panel Door – A door comprising panels framed together, often featuring raised or recessed designs.
  • Patio Door - A type of door commonly used to access outdoor areas, such as a patio, terrace, or garden. Patio doors are often large, featuring glass panels that maximize natural light and provide a clear view to the outside. 
  • Pivot Doors – A contemporary choice, these doors rotate on a center hinge, offering a larger entry opening and a modern look.
  • Pocket Doors – Sliding doors that retract into a wall pocket, ideal for saving space.

R

  • R-Value – A measure of thermal resistance; the higher the R-value, the better the insulation.
  • Rough Opening – The space in a wall where a window or door is installed before the frame is added.
  • Replacement Window – A window that fits into an existing frame for upgrades or repairs without complete structural changes.
  • Roll-Up Doors – Doors that roll up overhead, often seen in garages and storage units.

S

  • Sash – The part of the window that holds the glass and can move in operable windows.
  • Shims – Thin materials used to adjust and level doors or windows during installation.
  • Sound Transmission Class (STC) – A measure of sound insulation; higher STC ratings indicate better noise reduction.
  • Spacer Bar – A bar separating panes in an IGU, often filled with a desiccant to prevent condensation.
  • Sill – The horizontal bottom part of a window or door frame, providing structural support and weather protection
  • Slider Window – A window that opens by sliding horizontally..
  • Single-Pane Window – A window consisting of a single sheet of glass, offering minimal insulation.
  • Steel Frame Window – A window with a frame made from steel, providing high durability and security.
  • Skylight Window – A window installed in the roof to provide natural light from above, often operable for ventilation.
  • Sliding Windows – Move horizontally along a track, easy to operate.
  • Storm Windows – Installed outside regular windows for added insulation and protection.
  • Steel Door is made from steel, offering high security, durability, and energy efficiency.
  • Sliding Doors – Doors that slide on a track are widely used for patios or interior partitions.
  • Storm Doors – Additional exterior doors designed to protect against the elements.

T

  • Tempered GlassSafety glass that shatters into small, blunt pieces, reducing injury risk.
  • Threshold – The bottom part of a door frame, often slightly raised to improve weather resistance.
  • Transom – A small window above a door or window, adding ventilation and light.
  • Tilt and Turn Window – A window with a dual-function mechanism that allows it to tilt inward for ventilation or swing open for cleaning.
  • Transom Windows – Above doors or other windows, often for decorative purposes.

U

  • U-Factor – A measure of heat transfer through a window or door; lower U-factors indicate better insulation.
  • Utility Door – A door designed for non-residential buildings or accessing utility areas, often made from durable materials.

V

  • Vent – A part of the window that opens to allow airflow, typical in awning or casement windows.
  • Visible Transmittance (VT) – A measure of the visible light passing through a window, where higher VT allows more light.
  • Vinyl Door – A door made from vinyl, known for its low maintenance and energy efficiency.
  • Vertical Slider Window – A window that opens by sliding one or more sashes vertically.

W

  • Weatherstripping – Material installed around doors and windows to prevent air and water infiltration.
  • Weep Hole – Small openings at the base of a door or window frame for water drainage.
  • Window Film – A thin layer applied to glass for UV protection, privacy, or energy efficiency.
  • Warm Edge Technology – Spacers made from less conductive materials that reduce heat transfer at the edges of a window.
  • Weatherboard – A horizontal board used to cover the exterior wall of a building, sometimes used as trim around windows.
  • Wooden Doors – are classic and timeless, offering warmth and durability. However, they require maintenance to prevent weather damage.
  • Wrought Iron Doors – Heavy and secure, they add intricate details and are often paired with glass panels for a bold, traditional look.

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