Window Sizes

Choosing new windows for your home is an important task that should not be taken lightly. The more you educate yourself on basic window components and standard window sizes, the better equipped you will be to make the best choice for your home when it comes to window replacement.

There is a set of standard window sizes in Canada that serve to make window replacement as straight forward and simple as possible, allowing you to maximize the benefits of your new windows. These standardized window dimensions take a wide variety of window components into consideration, such as window profile, casings, brickmoulds, or jamb extensions.

The profile, or width of the window frame, is an incredibly important factor to consider when selecting new windows. Different window styles have differing window profiles, which can impact the amount of light that can enter a room as well as the level of glazing available.

Slider and End-Vent windows have lower profiled frames, while Awning and Casement windows tend to have higher profiles. Fixed picture windows are available in both high- and low-profile options, depending on your unique needs. The profile of each window frame directly influences the final surface area of the glass inserted into each window unit.

As mentioned, the dimensions of your window frame (the profile) impact the glass surface area of your window. The estimated surface area of the glass should help you make an informed decision when it comes to selecting windows for your home. Remember, the greater the surface area the more natural light that will enter your home.

It is important to note that this table specifically compares the difference between various sized high- and low-profile picture windows only. It is intended as a starting point to help you determine the appropriate size for your window replacement project.

Window casings, or window trim, also need to be considered when talking about window sizes. Window trim is installed around the window frame as the finishing touch and serve as a seal between your home and your windows. The trim you select can impact the overall aesthetic of your home, as well as the final dimension of your window. There are typically two standard casing measurements to choose from: 2 5/8 in. or 3 3/8 in. However, the shape of the window and the size of brickmould being used will impact the final casing measurement available for your replacement windows.

Brickmould for windows is a strip of material that is placed between your window casing and window wall. While it adds an attractive finishing touch to your windows, it is also essential in preventing air and water infiltration, which ensures the longevity and efficiency of your windows. Brickmoulds are generally manufactured to match existing brickmoulds on other windows in your home, the standard brickmould measurement being 1-inch (but can range anywhere from ¾ in to 7/8 in.). Brickmoulds can be used to adjust for minor differences in sizes between original and replacement windows.

Jamb extensions are also an important consideration when selecting replacement windows for your home. The size of jamb extension required is dependant upon the width of your window, as they are designed to fill the exposed areas that remain when the window frame is connected to the casing. Standard jamb extension measurements depend on wall construction. For example, homes with 2×4 walls generally require 1 3/8 in. jamb extensions while homes with 2×6 walls are typically fitted with 3 3/8 in. jamb extensions.

Just as there are building codes and specs for the size and style of your home, there are also regulations regarding allowable window sizes. Standard window sizes in Canada have been determined based on the minimum and maximum requirements set out by Canadian rules, which ensures dependable and reliable products from window manufacturers.

The following table outlines the minimum and maximum dimensions for various standard window frame sizes in Canada: