What You Need to Know About Mullions and Muntins

Your windows may have mullions or muntins. Typically, these elements are suitable for windows in Victorian and New England homes. Window mullions and muntins have an uncanny similarity, making it common for people to use the terms interchangeably. However, there is a subtle difference between them.

Mullions and Muntins

Continue reading to learn more about mullions and muntins.

What Are Mullions?

Mullions are large, single vertical bars dividing two sides of a window. Specialists call these mullions and serve as structural supports commonly used in a two-pane window design. These heavy and dense dividers can make a single unit look like two windows.

What Are Muntins?

Muntins are vertical dividers separating glass panes. Window replacement experts refer to the inner vertical pieces as muntins and the outer pieces forming the frame as stiles and rails.  

Much like mullions, muntins were structurally necessary. The outer walls of early buildings could not carry the weight of large windows, and muntins helped in distributing that weight vertically.

Grilles: The Modern Version of Mullions and Muntins

Muntins and mullions were necessary centuries ago because they provided additional structural support to the windows. Nowadays, whether they’re added to casement or double hung windows, muntins and mullions no longer serve any function. They are only meant to add aesthetic appeal. Furthermore, today’s window professionals refer to them as grilles, which are usually added to contribute to the design of a traditional-style home or preserve the look of a historic home. 

Renewal by Andersen® of Houston provides window installation services to customers in Houston, TX, and the surrounding areas. We offer a range of window styles, including sliding windows, bow and bay windows, specialty windows and more. We also provide sliding patio doors and French patio doors to suit various homes. Call (281) 547-6177, or fill out our contact form to schedule a consultation.