Simply put, window mulling is the process of joining two windows together. Mulled replacement windows are connected to each other by their frames.
What are the benefits of having two separate windows combined?

The Advantages of a Mulled Window
For one thing, the combined glass area of two windows can let in more sunlight, which can make a cramped interior feel more spacious and improve the mood in a room. Plus, a wider glass area gives you a better view of the scenery outside. Design-wise, a mulled window would serve as a larger visual focal point that can help draw more attention to your exterior or highlight certain features in your interior.
Factors to Consider Before Combining Window Units
You can purchase new mulled windows, or you can have contractors combine the windows in your home. However, not all windows can be mulled. Your contractor will need to take into account several factors, such as the window glass area and the size of the window itself. There’s usually a limit to how big a mulled window can be – if the combined window units are too big or heavy, your home’s walls may not be able to support your mulled window.
Mulling your windows might also void their manufacturer’s warranty. As such, before making a decision, you should go through the window warranty or check the window manufacturer’s website.
Window-Shopping Tips
If, however, you decide to purchase mulled windows, make sure to look for the ENERGY STAR® label, which indicates a window has met energy performance standards. After all, since mulled windows have a wider glass area, there’s a higher chance heat can escape or pass through the window glass. For more window-shopping tips, consult an experienced contractor.
WMGB Home Improvement, a company with more than three decades of experience, offers a wide variety of premium windows, including egress window options. To get a free quote, call us at (616) 243-3700, or fill out our form here. We serve homeowners in Kalamazoo and Grand Rapids, MI, as well as the surrounding communities.