Air infiltration
Infiltration is the unintentional or accidental introduction of outside air into a building, typically through cracks in the building envelope and through use of doors for passage.

Argon is the third most common gas in the Earth’s atmosphere, at 0.93% - making it more common than carbon dioxide. Argon is colorless, odorless, and nontoxic as a solid, liquid, and gas. It is used for thermal insulation in energy efficient windows.

Window style with a top-hinged sash that swings out at the bottom.

A multi-panel window, with three panels set at different angles to create a protrusion from the wall line.

A multi-panel window, with more than three panels set at different angles to create a protrusion from the wall line.

Is a transitional moulding or casing, which goes around the frame of exterior door or window openings. Forming the outer edge of a door or window frame, brickmould conceals the gap between the exterior cladding of the structure and the door or window jamb.

Window style consisting of a side-hinged sash that opens left or right, similar to a door.

A maintenance-free material that is placed over another material for added performance or aesthetic appearance.

The altering of a gas to a liquid form. Warm air can hold more vapor than cold air. When warm air cools, its ability to hold water vapor reduces proportionately. Excess moisture then condenses on the warm side of the glass.

Egress window
A window big enough and low enough so that occupants can escape through the opening in an emergency, such as a fire. In Canada, exact specifications for emergency windows in bedrooms are given in many building codes.

Energy Rating
The Energy Rating (ER) value is calculated using a formula that balances a product’s U-value with its potential solar heat gain coefficient (SHGC) and its air-tightness. The higher the number, the more energy efficient the product.

ENERGY STAR is an international standard for energy efficient consumer products. It was first created as a United States government program by the Clinton Administration in 1992, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted the program.

The associated head, jamb and sill that houses the sash or glazing units.

Installation of glass into a window or door frame. Also refers to various glass types.

Glazing Stops
PVC components which hold the glass securely to the sash. Located at the perimeter of the glass, on the interior of the sash.

Modern windows are usually glazed with one large sheet of glass per sash, while windows in the past were glazed with multiple panes separated by “glazing bars”, or “muntins”, due to the unavailability of large sheets of glass. Today, glazing bars tend to be decorative, separating windows into small panes of glass even though larger panes of glass are available, generally in a pattern dictated by the architectural style at use.

Horizontal Slider
Windows with a fixed sash and a sash that slides horizontally.

The horizontal member at the top of a window or door frame.

Hinged Doors
A door unit that swings inward or outwards with the aide of a series of hinges affixed to the edge of the door slab and the door frame.

Insulated Glass Unit (IGU)
A combination of two or more panes of glass, factory sealed using a spacer bar and sealants.

The upright or vertical members of window and door frames.

Low-e Coating
Specially designed coatings, often based on metallic oxides, are applied to one or more surfaces of insulated glass. These coatings reflect radiant infrared energy, thus tending to keep radiant heat on the same side of the glass from which it originated, while letting visible light pass. This often results in more efficient windows because: radiant heat originating from indoors is reflected back inside, thus keeping heat inside in the winter, and infrared radiation from the sun is reflected away, keeping it cooler inside in the summer.

Multi-Point Hardware
Hardware type which locks at multiple points. This type of hardware is used on door units, as well as casement windows.

Polyvinyl chloride, (IUPAC Poly(chloroethanediyl)) commonly abbreviated PVC, is a thermoplastic polymer. UPVC or Rigid PVC is often used in the building industry as a low-maintenance material.

Rotary Hardware
Hardware located on operating windows (Awnings & Casements) used to open and close the sash.

The R-value is a measure of thermal resistance used in the building and construction industry. Under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux. The bigger the number, the better the building insulation’s effectiveness. R-value is the reciprocal of U-value.

Rough Opening
The hole in a building envelope that a window or door will be placed into. The rough opening is generally 1” larger than the frame size.

The inner frame which holds the glass units in a fixed or operating window.

Screen Bar
The aluminum surrounding frame which houses the insect screen.

The horizontal member at the bottom of a window or door frame.

Single Hung
Windows with an upper fixed unit and a lower sash which operates upward.

Sliding Patio Door
Door unit with a fixed door slab and a slab that slides horizontally. Dependent on the model type, both door slabs may move.

Solar Heat Gain Co-efficient (SHGC)
Solar gain (also known as solar heat gain or passive solar gain) refers to the temperature in a space, object or structure that results from solar radiation. SHGC is expressed as a number between 0 and 0.87, The lower a window’s SHCG, the less solar heat it transmits, and the greater its shading ability. SHGC may be expressed in terms of the glass alone or may refer to the entire window assembly.

Strike Plate
The metal plate affixed to the locking side of the door jamb. Used to re-enforce and for adjusting the door slab against the weather-stripping.

The U-value (or U-factor), more correctly called the overall heat transfer coefficient, describes how well a building element conducts heat. It measures the rate of heat transfer through a building element over a given area, under standardized conditions (Lower U-values represent more energy efficient windows).

A component of a window or door used to seal edges and gaps from exterior elements.