A window casing — is the decorative frame around an opening on the façade, whether a window or a door. It also serves a structural purpose, covering the gap between the wall and the frame.

It can be open, U-shaped, or wrap around all four sides.

Every architectural style brought its own features to the look of the casing. The Baroque style, for example, is known for casings with ears and stucco.

Modernism calls for less opulence and more elegance.

Russian carpentry, starting in the 15th century, introduced openwork carved casings with rich ornamentation.

In the conservative version of the English style, the window frames are restrained — light stone set against dark brick.

Modern casings can be styled in many different directions, using materials such as coated polystyrene foam, fiber-reinforced concrete, fiberglass, natural stone, and more.