Boss (architecture)

In architecture, a boss is a decorative knob on a ceiling, wall or sculpture.

Bosses can often be found in the ceilings of buildings, particularly at the keystones at the intersections of a rib vault. In Gothic architecture, such roof bosses (or ceiling bosses) are often intricately carved with foliage, heraldic devices or other decorations. Many feature animals, birds, or human figures or faces, sometimes realistic, but often Grotesque: the Green Man is a frequent subject.

The Romanesque Norwich Cathedral in Norfolk, United Kingdom, has the largest number of painted carved stone bosses in the world; an extensive and varied collection of over one thousand individual pieces. Many of these decorated bosses still bear the original gilt and pigments from the time of their creation.