Window Types

    Great windows are a powerful selling point


    Windows bring light and air to an interior space and provide a view of the outdoor scenery. In older houses, windows may have just one layer of glass per pane, which is called single glazing. More contemporary and energy efficient windows have two layers of glass per pane, or double glazing. Low-emission glass, referred to as "Low-E" glass, has a special coating that allows light to enter a room but prevents heat from escaping; this is used to conserve energy.


    Bay windows project from the side of a house, adding light and extra square footage to a room. The area inside a bay window creates a cozy nook well-suited for a window seat or a dining area.

    Box bay

    Box bay windows project from the side of a house. They have a square shape with 90-degree angles at the corners. The shape of the window creates a shelf that's ideal for added space in front of a kitchen sink or a desk.


    Casement windows hinge on one side of the window frame so they open like a door. These are widely used in both traditional and contemporary design. Casement windows are typical of the Tudor style of architecture and are particularly convenient over a kitchen sink where it's easier to open a window with a hand crank than to lean over a countertop and push up.


    Bow windows project from the side of a building like bay windows, only with a curved shape. It's typically more expensive to build a bow window than a bay window.


    Double-hung windows have two sashes that slide up and down vertically. Early double hung windows had many panes of glass per sash and were called "12 over 12," meaning 12 panes per sash. This is a common type of window that is quite versatile, as you can open it a little or a lot from either the top or the bottom.

    Label Mold

    Label molding is a horizontal projection over a window or doorway that drops vertically to about a third of the way down the sides of the opening. This type of molding, like hood molding, is used to divert rainwater away from a doorway or window. Label molding was used in Gothic and Tudor architecture.

    Ribbon Windows

    Ribbon windows are a row of windows separated by vertical posts, called mullions. Ribbon windows can be used up high on a wall to bring added light to a room. Windows installed near the ceiling like this are called clerestory windows.


    Oriel windows project from the side of a building, like a bay window, but are located on the second floor or higher and supported by brackets or columns. Oriel windows bring added light and space into a room and have been used in many styles of architecture.

    Paired windows

    Paired windows are two windows next to each other often times under an arch. The support between the windows is called a mullion.

    Hood Mold

    Hood molding is the projection from a wall over an arch. This type of molding, seen typically in Gothic architecture, was used to protect the archway from rainwater. It also serves as a decorative frame for the top of an arch.


    Palladian windows are named after the 16th century Italian architect Andrea Palladio, who used this window design in developing what is known as the Palladian style of architecture. This window will be a focal point in a room and has been widely used in a variety of traditional architectural styles.

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