Get a FREE Quote

By submitting this form, I agree to be contacted by a window dealer in my area to schedule a free consultation, as well as receive product information by email. I understand I may also call your service center at (844) 247-6226 to be put in contact with a local window dealer.

Sashes, argon, grilles, glazing — what do all of these things mean? At Great Lakes Window we’re working hard to serve our customers by offering quality windows and doors. But for those who are trying to learn more about their replacement window and door options, some of the window terms can be confusing. As always, we’re here to help with this glossary!


Argon Gas

Argon gas is colorless and odorless. We use it to fill the space between panels of window glass, adding insulating performance to our window products. Learn more about our energy efficient windows here.


Air Infiltration

This refers to the amount of air that can leak in or out of a building. In the context of windows and doors, it’s air that enters or escapes through or around these products. An energy efficient home is one with windows and doors that reduce and discourage air infiltration.



Casing can be internal or external. It covers the space between a frame and the wall.



The window or door frame is the part that does not move. In our windows, the frame encloses the sash.



Glazing is the installation of glass into your windows and doors. It can also refer to the glass itself. You may hear about single glazing or double glazing, which refers to the number of panes within each window or door construction.



Grilles are decorative elements that divide a window or door, attached on the interior of the sash or fitted inside of a glass unit. It’s less expensive and time consuming than glazing each individual panel of a divided light door or window. You can see our grilles and designer glass options here.


Heat Gain/Loss

This refers to the transfer of heat between a home and the outdoors. Heat gain is when heat goes from the outside to the inside, and heat loss is when heat goes from inside to outside. Well insulated windows will prevent this from happening.



This stands for low emissivity. The lower emissivity is, the more glass blocks solar radiation, which means you get better protection from heat (or thermal protection). Check out our UV resistant windows here.


Rough Opening

You might hear our dealers using this window term, which refers to the opening in a wall where your window or door will be installed. It’s bigger than the actual window or door unit, to leave room for installation, so don’t be worried if it seems large. Our dealers are highly experienced and skilled, and your final installation will look great.



A window sash is separate from the frame, made up of vertical and horizontal stiles and rails. It holds the glass itself.


Our dealers are experts on all things windows and doors, so if you have any questions about the window terms in this glossary, want to learn more about your window and door options, or are otherwise looking for information about all that Great Lakes Window has to offer, find a dealer today.

Comments are closed.