Bay windows have a long and rich history, showing up everywhere from medieval castles to modern American apartments. The term probably originates from the large windows that were located in the bay, or the area between the window frame and the interior wall, of a castle. This was often a dramatic looking area of the castle, with a high table or other type of dais standing in front of the window, where it could be best seen. While they had a medieval beginning, bay windows gained popularity in the Victorian era.
These windows tend to be very striking and beautiful, but they can also make small spaces appear larger and dramatically increase the amount of light in a room. In addition, bay windows tend to blur the visual boundary of a wall, making it look like the room opens right up into the open air. In fact, they can feel much like a porch or a balcony, only inside and safe from the weather.
Much of the effect of a bay window is visual, making the room feel larger and the wall farther away, but a bay window does actually provide more space as well. This extra space can be used for storage, as a bench for reading, or for many other purposes. Many bay windows are located in living rooms or sitting rooms, where they provide a comfortable place for curling up with a cup of tea and a book.
There are a few different types of bay windows, but they all bow out from the main wall, forming a space that can be round, square, or polygonal. The most traditional form of bay windows have angles of 90, 135, or 150 degrees, but many variations exist. Bay windows can be sash windows or casement windows, for example.
Box bay windows have a 90 degree angles to make a box shape. They include one large window with smaller windows on either side, often with storage or a sitting area in the middle. Other types of bay windows may have more sides and wider angles, such as 135 or 150 degree angles.
Bow windows are just curved versions of bay windows. They contain at least four window panes in a semicircle. This version of the bay window started during the Georgian period and became quite fashionable in Regency-style architecture. They were often used in English country homes, because they provided a view without the discomfort of being outside during cold and damp weather, which the English countryside has a lot of. A circle bay window is an even more pronounced bow window.
Oriel windows are another type of rounded bay window. They tend to exist on the upper floors of buildings and do not reach down to the ground level, but are closer to enclosed balconies. During the Gothic period, they often contained home chapels. In Middle Eastern architecture, these windows are common also, and are called mashrabiyas.
In England, bay windows gained popularity in the late 1800s, due to some changes in London building codes that allowed houses to have windows that weren’t even with the exterior wall. In the United States they became popular around the same time and have remained fairly common ever since. Today, bay windows can be found in many different styles of architecture as people tend to be instinctively drawn to them, whether or not they know the history.