What terminology should I become familiar with while shopping for windows and doors?

When replacing the windows in your home, you may be faced with a number of terms and phrases that are unfamiliar. Nobody should make you feel uncomfortable by using language that leaves you wondering what they mean.

Here are some terms it would be beneficial for you to become familiar with:


Small honeycomb spaces within the sash and frame which help to insulate and strengthen the window.

The amount of air that passes between a window sash and frame. In windows it is measured in terms of cubic feet or air per minute, per square foot of area. The lower the number, the less air the window lets pass through.

Special features such as Argon gas is combined with Low-E coating to increase energy efficiency and improve the insulation value of your windows. Argon gas is used to fill the space within the panes of glass, which are called “sealed units”. Argon gas which is non-toxic, non-reactive, clear and odorless is heavier than air. It is inert–only moving under pressure–and so minimizes convection currents which can occur inside the sealed unit. On cold winter days, this reduces the tendancy for windows to collect frost starting at the bottom of a window gradually moving upwards, as the argon gas evenly distributes the tempurature inside the sealed unit.

An astragal is commonly used to seal between a pair of doors. The astragal closes the clearance gap for the purpose of either providing a weather seal, ensuring privacy, preventing sound from leaking in or out of a room, minimizing the passage of light between the doors, or retarding the passage of smoke or flame during a fire.

Doors are typically the weakest link in any partition that is designed to block sound. This is often due to poor sealing around the perimeter of the door. Astragals, perimeter gasketing, drop seals and door sweeps can all be used to prevent sound from leaking through cracks around the door perimeter.

Covers the balance cavity holding the coil-spring balance system inside the jamb.

Device for holding vertically sliding sash in any desired position through the use of a spring or weight to counterbalance the weight of the sash.

The brickmould is on the outside of the window or door and enhances your home’s exterior appearance. It attaches to the frame and makes the overall window appear larger. The brickmould also covers the gap between your home’s exterior (siding or brick) and the window frame.

Frame Out installation, also called Brick to Brick installation, is the recommended solution to your window project. This method removes the entire frame and is taken back to the studding of your home. Insulation is placed around the inside and outside of your new frame. All new trim is installed on the inside of the window and maintenance free vinyl finish on the outside. Aluminum capping is available upon request.

Advantages: eliminates all rot and mould from wood frames in the building envelope, extremely energy efficient, maintenance brick mould on the outside, fresh trim on the inside of your home. Full window installation can be excellent, and depending on the type of windows you want, this might be your only choice, it’s best to work with an experienced window installer to ensure that the job is done correctly.

A rubber material that seals the glass to the spacer, creating an airtight and water-tight IG unit. Butyl has the lowest gas permeability of all rubbers.

The mechanisms which pull the sash together when placed in the locked position.

A measure of the effectiveness of a window or glazing system to reduce the potential for condensation. The higher the condensation resistance factor, the more efficient the window and glazing system.

Energy transfer from one material to another by direct contact.

Heat transfer by currents that flow from a warm surface to a colder one.

The space between the panes of glass of an I.G. Unit.

A direct set side lite creates brighter spaces as light is able to travel through a larger opening. Equally safe as they are beautiful, each direct set side lite glass is custom-made and sealed inside two panes of tempered glass.

Decorative, clear or wrought iron glass inserts that is installed into an entry door when it is manufactured.

The relative ability of a surface to reflect or emit heat by radiation. Emissivity factors range from 0.00 to 1.00 and are typically measured in a U-Value (or it’s inverse R-Value). The lower the emissivity, the less heat that is emitted through a window system.

An ER-Rating is derived from solar heat gain, heat loss through frames, centre and edge of the glass, and air leakage heat loss. The combined effect is measured in number of watts per square metreand is either positive or negative. A positive number represents a net heat gain and helps in reducing the home’s heating costs. A negative number indicates that the product loses more energy through heat loss and air inflitration than it gains in solar energy absorbed from the sun (i.e. the home’s heating system has to work harder in colder weather).

ER-Ratings range widely depending on the type of window and design options. For example fixed windows score better ER-ratings than operating ones. Operating windows and sliding doors typically have a negative ER- number ranging from -30 (indicating weaker energy performance) to -5. Fixed windows can be designed to have positive numbers ranging from -20 to +10.

A fixed side lite creates the impression of a seemless alignment with the door. It magnifies an entranceway. Reinforced with aluminum the fixed side lite can also be modified to include Atlantic’s casement or hung windows.

The process of joining materials by melting them together with extreme heat (over 500ºF), resulting in the materials uniting into a one-piece unit.

The process of sealing the glass to the sash.

A strip of vinyl which surrounds the edge of the glass and holds it in place in conjunction with other sealants.

Decorative horizontal or vertical bars installed between the glass panes to create the appearance of the sash being dividing into smaller lites of glass.

The horizontal top portion of the main frame.

A vinyl shape cut the width of a product and placed on the head, fitting over it snugly. This piece is used as a filler to expand or lengthen the unit from the head and take up the gap in the opening between the unit and the opening in the unit.

Two or more lites of glass separated by a spacer and hermetically sealed at the glass edges.

Solar heat that passes through a material and is captured naturally, not by mechanical means.

Renovating your home should be a positive experience, enjoyable and free from worry and stress. You should have full confidence in your renovator and know that you are getting the best. That’s why you should look for a RENOMARK renovator as your assurance that you have hired a professional who will provide high quality services.

The RenoMark program is nationally sanctioned by the Canadian Home Builders’ Association and has been adopted by local associations coast to coast. Central to the entire RenoMark program is the renovation-specific Code of Conduct designed to benefit and protect you- the homeowner.

Retrofit windows are great options for those on a tight budget. These windows replace the glass in your old window frames, but leave the frame alone. Retro-Fit installation, also known as Frame-In installation, is the least expensive method of replacing your windows. The Master Frame stays in the opening and so does all your interior trim. The exterior is finished off with maintenance free aluminum capping.

Measures the resistence of heat transfer through the glass. The higher the R-Value, the better the window insulates.

Sealed units can be double or triple glass window panes separated by an air or other gas filled space to reduce heat transfer across a part of the building envelope.The glass panes are separated by a “spacer”. A spacer is the piece that separates the two panes of glass in an insulating glass system, and seals the gas space between them.

A side lite is a window usually with a vertical emphasis, that flanks a door. Sidelights are narrow, usually stationary and found immediately adjacent to doorways.

A measure of the rate of nonsolar heat flow through a material or assembly. The lower the U-Value, the greater the window’s resistence to heat flow and the better the insulating value.

The percentage or fraction of the visible light spectrum that is transmitted through the glass of a window or skylight as reduced by the sash material and reluctance of the glass.