What is a mulled window?

A mulled window is a type of window that is created by combining multiple individual windows into a single unit. These windows are typically used when a larger window is desired or when several smaller windows need to be combined in order to create a specific aesthetic or function. The process of mulling involves joining the frames of the individual windows together, which creates a seamless appearance and helps to improve energy efficiency. Mulled windows can be made from a wide variety of materials, including wood, vinyl, fiberglass, and aluminum. They are commonly used in residential and commercial buildings and can be customized to meet specific requirements and design preferences.