Bow Windows | Bow Replacement Windows

What Is a Bow Window?

The bow window is European in origin, first appearing in Britain in the 1700s. In fact, bow and bay windows are considered typically British. Bow and bay windows were created to allow the English to enjoy their much-loved country gardens and landscapes without suffering the effects of the typically inclement weather. By extending the room beyond the fixed walls of the house, bow and bay windows are meant to situate the viewer outside while still allowing him or her to enjoy all the creature comforts of home (chiefly staying warm and dry).

Bow windows migrated to the U.S. between 1780 and 1830, during the Federal period. Almost two hundred years later, in the 1970s and 1980s, bow windows experienced another upswing in popularity in both the US and the UK. Today they can be seen in period (or period inspired) architecture such as Tudor, Queen Anne, Victorian, and Federal structures, but they can also be seen in many other styles, including contemporary. The curve of the arc can be as full or flat as desired, and the shape is often chosen to match the building's style.

Replacement bow windows add ventilation and light to any room, making it seem warmer and more inviting. Bow windows are not flush with the wall of the home, so they add dimensions to the house – inside and out. They introduce a heightened sense of realism, because they place the home outside and bring the outside in, just by manipulating the sense of space and altering the limits of the room.

Replacement bow windows can be used on any level of the house and in any room that lends itself to the dramatic flair they can provide. Bow windows offer a broader view of the world beyond – much greater than what a typical in-wall window can offer. Bow windows can even be stacked to span multiple floors, creating an inviting wall of sunshine.

Replacement Bow Windows: Combinations

Bow windows are not flush with the window space they occupy. Replacement bow windows are designed to extend a home's viewing area, projecting out from the fixed plane of the wall. This is accomplished by combining windows in a series that stretches in an arch from one side of the space to another, but at a distance from the wall. This opens up the area and creates a panoramic view of the garden, ocean, mountains, or city just beyond the window. In creating this scenic space, the soft, graceful arc of the window itself becomes a focal point of the room.

To fashion a continuous arc that is gentle and not jarring, with curves and no sharp angles, four or more windows are joined in a half-circle that spans the space and creates an elegant rounded shape. The window configuration is usually made with fixed or vented casement windows, but double-hung or picture window combinations are also possible.

In most bow windows, the window lites are equal in size and arranged to form a gentle curve. This differs significantly from the bay window, whose central pane is typically larger than the others and which juts out from the house using sharp (usually 30- or 45-degree) angles.

Bow Window Structure and Components

Head and seat boards, typically stainable or veneered, serve to improve the interior aesthetics but also to close the openings created by the window's bow. Many manufacturers produce insulated seat boards for improved efficiency. Edge banding finishes the exterior, wrapping and protecting the hardwood veneer, making casing installation easier, and offering additional moisture protection. For support, bow windows generally utilize threaded steel rod mulling, turnbuckles, and a cable-free chain support system, possibly with an external knee brace.

Replacement bow windows, which project beyond the home's original frame, generally require their own roof system. They can incorporate a custom or prefab roof system, or a roof clad kit in copper or Kynar® painted aluminum. Sometimes a bow or bay window, depending on how deep the eaves are, can be tucked under the roof overhang without adding a separate roof structure. Other homeowners might choose a glass roof for their bow window, making it a greenhouse window, to take full advantage of the sunlight.

Most bow windows are formed by the window configuration and a seat board that encloses the window, and do not have any structure beneath them. However, walk-out bow windows are another option, with the floor extending out to meet the window projection. This involves significant changes to the home's structure and requires joists or other supports (even a new slab on first floor walk-outs), but the result can be quite stunning.

Bow Window Patterns

Bow windows tend to be a series of 4 windows set at 10 degrees, or 5- or 6-panel windows at 15 degrees, although the arch can be as shallow or pronounced as desired (and include more windows). For a fuller, rounder curve, more windows will be necessary. The greater the contrast between the window's arc and the wall's flat plane, the more striking the window will be.

The lites of a bow window may be any combination of fixed and operable windows and any configuration of window types, though casement configurations are the most common. Many replacement bow windows feature only a few functional windows (often just the windows at each end) with fixed center windows. The terminal windows are usually the operable windows because they are uniquely situated to capture the breezes that a bow window is exposed to.

As bow windows project from the wall, they are ideal sources of natural cross-ventilation. However, while it's possible for all of the windows to be operable, it's also an option to have none of the windows vent and to install the entire bow window as a fixed-frame unit.

Bow Window Support and Efficiency

Bow windows require extra support because they are cantilevered from the wall. Replacement bow window designs often involve sophisticated chain support systems, knee braces, and changes to the floor joists. Walk-out bow windows require even more structural modifications.

One thing to note when considering replacement bow windows is that, due to their protrusion from the wall, bow windows receive more exposure than traditional windows. Bow windows with seat board insulation and low-E glass are recommended. Other energy-efficient features include gas fills, foam-insulated mullions and frames, and glazing beads for water tight seals.

A Summary of Bow Windows

A replacement bow window adds a dramatic flourish to any room, and depth to a home's exterior. Replacement bow windows bring the outside in by expanding the view and pushing the room into the great outdoors, beyond the limits of the wall. Bow windows add dimension to a room, inside and out.

Bow windows introduce a softer, subtler change to the shape of a room than a bay window's jutting angles, but achieve the same effect. A bow window will transform a room, introducing more natural light and making the room seem brighter, larger, and more inviting. Replacement bow windows can be installed in the existing window space without modifications to the home's structure. Replacement bow windows are graceful, stylish, and memorable, and are a cost-efficient way to add value and beauty to your home.