What Is a Cornice? It Depends On Whom You Ask

Cornice Types Can Be Decorative and Functional

Detail of a building cornice in downtown Madrid, Spain
Detail of a building cornice in downtown Madrid, Spain. Photo by Bartomeu Amengual/Stockbyte/Getty Images

In Classical architecture, and even Neoclassical, a cornice is the uppermost horizontal area that protrudes or sticks out, like moldings along the top of a wall or just below a roof line. It describes an area or space that overhangs something else. As space is a noun, cornice is also a noun. Crown molding is not a cornice, but if the molding hangs over something, like a window or air vent, the protrusion is sometimes called a cornice.

The function of the cornice overhang is to protect the structure's walls. The cornice is traditionally by definition decorative.

However, cornice has come to mean many things. In interior decorating, a cornice is a window treatment. In hiking and climbing, a snow cornice is an overhang you don't want to walk on because it is unstable. Confused?  Don't worry if this is too difficult to comprehend. One dictionary describes it this way:

cornice 1. Any molded projection which crowns or finishes the part to which it is affixed. 2. The third or uppermost division of an entablature, resting on the frieze. 3. An ornamental molding, usually of wood or plaster, running round the walls of a room just below the ceiling; a crown molding; the molding forming the top member of a door or window frame. 4. The exterior trim of a structure at the meeting of the roof and wall; usually consists of bed molding, soffit, fascia, and crown molding.— Dictionary of Architecture and Construction, Cyril M. Harris, ed., McGraw- Hill, 1975, p. 131

Where does the word come from?

A way to remember this architectural detail is to know where the word comes from—the etymology or origin of the word. Cornice is, indeed, Classical because it comes from the Latin word coronis, meaning curved line. The Latin is from the Greek word for a curved object, koronis—the same Greek word that gives us our word crown.

Types of Cornices in Architectural History:

In ancient Greek and Roman architecture, the cornice was the uppermost part of the entablature. This Western building design can be found throughout the world, in various forms including:

  • architrave cornice, which has no frieze beneath it
  • cavetto cornice or Egyptian gorge
    (view Figure 67, The Egyptian Gorge or Cornice, from the Project Gutenberg EBook of A history of art in ancient Egypt, Vol. I by Georges Perrot and Charles Chipiez, 1883)

Cornice Types in Residential Architecture:

The cornice is a decorative architectural element not found in more modern homes or any structure that lacks ornamentation. Today's builders generally use the word eave to describe the protective overhang of the roof. However, when the word "cornice" is used in home design description, three types are common:

  • box cornice, illustrated by this Elevation Drawing from the James Longest House, Special Collections Research Center at NCSU Libraries
  • open or skeleton cornice, where rafters may be seen under a roof overhang
  • close or closed cornice, which offers very little wall protection and is often accompanied by gutters

Window and Door Cornices:

Since an exterior cornice is decorative as well as functional, the decorative cornice has made its way to interior decor, including window treatments.

The box-like structures over windows, hiding the mechanics of shades and drapes, are called window cornices. A door cornice may be a similar decoration, protruding over a door frame. These types of cornices often add an elegance and sophisticated formality to interiors.

What is Cornice Molding?

You may see what's called cornice molding (or cornice moulding) at the Home Depot store all the time. It may be molding, but it's generally not used in a cornice. The interior molding may have stepped projections, like a Classical exterior cornice design, but it's more of a marketing description than architectural. Still, it's commonly used. The same goes for window treatments—What is the Difference between Valances, Swags, and Cornices?

Source: Webster's New World College Dictionary, Fourth Edition, Wiley, 2002, p. 325