As you plan your window replacement project, you might encounter unfamiliar terms such as “muntin” and “mullion.” They sound almost alike which is mostly why their definitions tend to be confused with each other. Renewal by Andersen® of Phoenix explains the differences between the two here:
Mullions
According to the Oxford English Dictionary, a mullion is essentially the vertical bar between the glass panes of a window. Compared to muntins, mullions are traditionally designed to divide larger window frames and are often heavier. Mullions also traditionally refer only to the vertical pieces of wood separating the panes of glass.
Muntins
Although modern muntins are also associated with windows, they actually refer to any kind of vertical divider for doors, wood panels and furniture. They’re also referred to as the vertical dividers that separate glass panes in windows. Muntins were first designed with a functional purpose of providing additional support to the outer walls of early structures that had large windows. Without them, the walls alone were unable to carry the weight of the large glass in windows. Muntins are a structural necessity as they essentially keep the weight transmitted vertically.
What’s the Difference?
For many window companies, differentiating the two words isn’t much of a priority. That is because not all buyers take the time to understand their similar definitions. However, it helps to know the difference if you’re planning to add them as a visual upgrade for your new windows. They don’t normally affect a modern window’s performance, after all, as they’re simply made by sandwiching thin strips of aluminum or plastic between a double-paned glass.
Alternatively, you can consider grilles instead if you want to add such design elements to your windows. Both mullions and muntins often fall under this category as it’s a universal term that’s also easy to remember. Grilles also encompass other terms such as grids and windowpane dividers.
For your window replacement needs, get in touch with Renewal by Andersen of Phoenix by calling (602) 562-1176 or filling out our online form for a consultation. We serve homeowners in Scottsdale, Phoenix and the surrounding communities.