Types and Parts: Glazing

Glazing refers to the glass portion of a window. Window can have one or multiple panes, and glazing is one of several important factors that determine a window’s energy efficiency or suitability in a specific climate. The Window Selection Tool considers the number of panes in windows to suggest options ideal for your house.   

Single-glazed windows are the most affordable but least-efficient option. They allow the greatest amounts of sunlight and heat to pass through them.

Double-glazed windows are the most popular choice in the U.S. because they balance efficiency and affordability. Double-glazed windows offer more efficiency options, which can lead to lower monthly utility bills by reducing reliance on heating and cooling systems. Those options include low-e (emissivity) coatings, which are transparent and block specific types of sunlight from passing through them, and filling the space between the panes with safe, non-toxic gases that reduce the amount of heat passing through a window. 

Triple-glazed windows are typically the most energy-efficient windows widely available, but also the most expensive. Like double-glazed windows, they are available in a variety of configurations.