What Is a Cornice?

The horizontal moulded band that projects out at the top of a wall or building, capping it and casting a shadow line against the sky, is a cornice. It is one of the most common and least noticed elements in architecture — yet a cornice does real work, both visually and practically. It crowns and completes a facade, gives it a finished edge, and, by projecting outward, throws rainwater clear of the wall below. From classical temples to terraced houses to the tops of interior walls, the cornice is everywhere once you start to look.

This article explains what a cornice is, where it came from, the practical job it does in shedding water and shadow, the main types — including interior cornices — and why it remains a useful element in both traditional and contemporary design.

What a cornice is

A cornice is a projecting, usually moulded element that runs horizontally along the top of a wall, building or other architectural feature, crowning and finishing it. Its defining characteristic is that it projects outward beyond the face of the wall below, creating an overhang and a strong horizontal line at the top of the composition.

The word and the form come from classical architecture, where the cornice is the uppermost of the three parts of the entablature — the horizontal band carried by columns, made up of the architrave (bottom), the frieze (middle) and the cornice (top, projecting). In that context the cornice is the crowning, overhanging member that completes the order. By extension, the term is now used for any projecting moulding that caps a wall, a building, a door or window, or the junction of wall and ceiling indoors.

Where the cornice came from

The cornice originates in the classical architecture of ancient Greece and Rome, as the top element of the entablature in the Doric, Ionic and Corinthian orders. In the Greek temple it was a richly profiled band, often with carved detail such as projecting blocks (mutules or modillions) on its underside, crowning the colonnade and forming the base of the pediment above.

From the classical tradition the cornice passed into the whole Western architectural language. Through the Renaissance, Baroque, Georgian, Victorian and later classical revivals, the cornice remained the standard way to crown a facade and give it a dignified, finished top. Even buildings that were not strictly classical adopted the projecting cornice as the natural way to terminate a wall against the sky. It became so habitual that a wall without a cornice can look oddly unfinished, as if it has been cut off rather than completed.

What a cornice does: shadow and water

A cornice is not only decorative; it does two practical jobs that explain its enduring use.

First, it sheds water. By projecting outward beyond the wall face, a cornice throws rainwater running down off the roof or upper wall clear of the wall below, so the water drips off the front edge rather than running down and staining or saturating the facade. A well-designed cornice usually has a small groove on its underside, called a drip, that stops water from creeping back along the underside and running down the wall by surface tension. This water-shedding function protected masonry walls long before modern guttering, and it remains a genuine benefit.

Second, it gives the facade a strong horizontal line and shadow. The projection casts a deep shadow beneath it, emphasising the top of the building and visually “capping” the composition. This shadow line gives a facade weight, finish and proportion, and helps relate the building to its neighbours along a street. The cornice line is one of the elements that gives a street of buildings its rhythm and coherence.

Types of cornice

Cornices take several forms depending on where and how they are used:

Classical entablature cornice: the crowning member of an architectural order, richly profiled and sometimes ornamented with modillions or dentils (small projecting blocks).
Building or eaves cornice: the projecting moulding at the top of a facade, often at or near the roofline, capping the wall and throwing water clear.
Parapet cornice: a cornice that crowns a parapet wall rising above the roof, common on terraced and commercial buildings.
Door and window cornice: a smaller projecting moulding capping an opening, sometimes combined with a pediment.
Interior cornice (cornice moulding): the moulding that runs along the junction of wall and ceiling inside a room, finishing the joint and adding character. This is the form most people encounter daily, and it is a familiar feature in interior design.

Cornices today and their upkeep

In contemporary architecture the elaborate classical cornice has largely given way to simpler ways of terminating a wall — a clean parapet, a recessed shadow gap, or a flush edge that lets the wall meet the sky without a projecting moulding. Modernism deliberately stripped away applied ornament like the traditional cornice in favour of plain, abstract edges. Yet the underlying ideas persist: many modern buildings use a projecting coping or a deliberate shadow line at the top of a wall to perform the same finishing and water-shedding roles in a stripped-back way.

For owners of older buildings, the cornice is also a maintenance matter. A heavy projecting cornice, especially in stone, masonry or moulded render, is exposed to the weather and relies on its fixings and the wall behind to stay in place. Over decades, water ingress, corrosion of embedded fixings, or decay of the supporting masonry can make a cornice unstable — and a projecting element high on a facade that becomes loose is a safety concern. Inspecting and, where needed, repairing or refixing cornices is part of keeping a facade safe. If you are assessing or restoring a building with significant cornices and need their condition and fixing checked, our structural-engineering consultancy can help, and you can get in touch to arrange it.

Frequently asked questions

What is a cornice?

A cornice is a projecting, usually moulded element that runs horizontally along the top of a wall or building, crowning and finishing it; its outward projection creates a strong horizontal line and throws rainwater clear of the wall below.

Where does the cornice come from?

The cornice comes from classical Greek and Roman architecture, where it is the uppermost, projecting part of the entablature carried by columns, above the architrave and frieze; from there it passed into the whole Western architectural tradition.

What is the practical purpose of a cornice?

A cornice sheds water by projecting beyond the wall so rain drips clear of the facade rather than running down and staining it, often aided by a drip groove on its underside; it also gives the facade a strong shadow line and a finished, dignified top.

What is an interior cornice?

An interior cornice is the moulding that runs along the junction between wall and ceiling inside a room, finishing the joint and adding decorative character; it is the form of cornice most people encounter in everyday rooms.

Do old cornices need maintenance?

Yes; a heavy projecting cornice is exposed to the weather and depends on its fixings and the wall behind, so over time water, corrosion or decay can make it unstable, and a loose cornice high on a facade is a safety concern that needs inspection and repair.

Restoring or assessing a building with significant cornices and need their condition checked? Talk to our consultancy or get in touch.