What's a Quoin? The Corner Stones

A Defining Architectural Detail

Accentuated corners or quoins on a 17th century mansion in England
Quoins on the Corners of Uppark Mansion in Sussex, England. Photo by Howard Morrow/Getty Images (cropped)

Quite simply, a quoin is a corner. The word quoin is pronounced the same as the word coin (koin or koyn), which is an old French word meaning "corner" or "angle." Quoin has come to be known as the accentuation of a building's corner with short side header bricks or stone blocks and long side stretcher bricks or stone blocks that may differ from the wall masonry in size, color, or texture.

Quoins are very noticeable on buildings. Sometimes they stick out more than their surrounding stone or brick, and very often they are a different color. The architectural detail we call the quoin or quoins of a structure is often used as decoration, defining space by visually outlining the geometry of a building. Quoins may have possible structural intent, also, to strengthen walls in order to add height. Quoins are also known as l'angle d'un mur or "the angle of a wall."

Quoins are most often found in European or Western-derived architecture, from ancient Rome, to 17th century France and England, and 19th century buildings in the United States.

Additional Definitions of Quoin:

"Prominently beveled stones (or wood in imitation of stone) used to give emphasis to corners."—George Everard Kidder Smith, Architectural Historian
"The dressed stones at the corners of buildings, usually laid so that their faces are alternately large and small."—The Penguin Dictionary of Architecture
"quoin: the dressed or finished stones at the corners of a masonry building. Sometimes faked in wooden or stucco buildings."—John Milnes Baker, Architect
"Large, prominent masonry units outlining windows, doorways, segments, and corners of buildings."—The Trust for Architectural Easements

About Uppark Mansion:

Sometimes it takes multiple definitions to get a true sense of architectural details. Uppark Mansion, shown here in Sussex, England, can use all of the definitions above to describe its quoins—the corners of the building are emphasized, the stones are laid "alternately large and small" at the corners, the stones are finished or "dressed" and are a different color, and the "large, prominent masonry units" also outline the facade protrusion, acting like columns that rise to the Classical pediment.

Built in approximately 1690, Uppark is a good example of how architectural details combine to form what becomes known as a style, which is really just a trend. Uppark's Classical elements of symmetry and proportion combine with medieval-era stringcourse—the horizontal band that seems to cut the building into upper and lower floors. The roof style invented by French architect François Mansart (1598-1666) is modified into the hipped slate roof with dormers we see here—all characteristics of what became known as 18th century Georgian architecture. Although used in ancient, Renaissance, and French provincial architecture, decorative quoins became a common feature of the Georgian style, after the rise of the line of British kings named George.

A National Trust property, Uppark House and Garden is remarkable to visit for another reason. In 1991, a fire gutted the mansion. The cause of the fire was workmen ignoring construction safety orders. Uppark is a fine example not only of quoins, but also of superior restoration and preservation of a historic manor house.

Sources: quoin, Encyclopædia Britannica online; Source Book of American Architecture by G. E. Kidder Smith, Princeton Architectural Press, 1996, p. 646; The Penguin Dictionary of Architecture, Third Edition, by John Fleming, Hugh Honour, and Nikolaus Pevsner, Penguin, 1980, p. 256; American House Styles: A Concise Guide by John Milnes Baker, AIA, Norton, 1994, p. 176; Glossary of Architectural Terms, The Trust for Architectural Easements [accessed July 8, 2017]