What are Bow and Bay style windows?

Bow and bay windows are valuable additions to many residential and commercial buildings. Here is a description of these windows.

Bay windows provide an attractive accent, increased ventilation and view; due to the fact that the flankers project from the building and face left and right.

A bay window is actually a collection of at least three window units including a left and a right flanker usually arranged at either 30º or 45º angles and at least one unit as a center window. See the picture above that shows the same sized window units being used as either a 30º or 45º bay unit. The 45º projects farther from building but the 30º is a longer window.

The window units can be either double hung (sash slide up and down) or casements (sash crank out). The flanker units are usually one of the above and the center units are usually picture units. Jamb sizes of units are usually 4-9/16”(depth) to fit 2x4 framed walls and extensions are added for other wall thickness’, for example 2x6 walls.

The designation of the assembly often consist of the angle and the name of the units, for example a double hung 45º 3442-18 would be 45º angle, 34 wide x 42 high center unit and 1’-8” (16” glass size) flankers, 42”high. Casement bay units are named much the same way although some manufacturers may have their own numbers for the unit.

Bow windows are assembly’s, like bays, but they are arranged at a much lesser angle, for example 10º or 12º, and bow windows therefore do not usually project as far from the building as bay windows. Each window assembly is usually made up of the same size casement units and all units open.