quoins

Quoins, or quoin, are masonry blocks used to form the exterior corner of a wall or building. They are typically larger and more precisely cut than the surrounding masonry and may be made from stone, brick, or other masonry units. The term can refer to the block itself or to the entire corner formed by arranged blocks.

Quoins serve both structural and decorative roles. Structurally, corner blocks help tie adjoining wall sections together and protect the edge of the wall from weathering and damage. Aesthetically, quoins emphasize the corner and can be fashioned with beveled, rusticated, or chamfered faces to create a pronounced profile. In many historic buildings, quoins are set so the edges project slightly, creating a visual frame for the façade. In some cases, through-quoins extend through the full thickness of the wall for added stability, though decorative, non-structural quoins are also common.

Originating in classical and medieval masonry traditions, quoins remain a common feature in Beaux-Arts, Neoclassical, and various revival styles, as well as in some modern constructions that seek a traditional look. The word quoin derives from Old French coing or coigne, meaning corner or wedge. Today, quoins are used to convey strength and durability while providing a defined architectural finish at building corners.