parapet

Parapet refers to a low protective wall along the edge of a roof, balcony, terrace, or other elevated edge. In architecture, parapets are designed to prevent falls and to shield workers and pedestrians from wind and weather. In fortifications, a parapet is a raised defensive wall along a rampart that allows defenders to observe and fire from above the parapet line. Some parapets are integrated into bridges and public structures.

The term comes from the Italian parapetto, meaning a little shield, from para- to shield and petto breast. Through Latin and French usage, parapet entered English in medieval and Renaissance periods, retaining both defensive and architectural senses.

Parapets are built of stone, brick, concrete, or modern reinforced concrete, and may be solid, open with balustrades, or crenellated with merlons and embrasures. Coping stones or metal caps protect the top edge from weather. On rooftops, parapets may house equipment, vents, or ductwork and can be designed as a decorative element or a safety barrier. In bridges and balconies, parapets often incorporate railings or glass panels.

Modern parapets are subject to building codes and safety standards that specify height, load, and infill requirements to prevent falls and to resist wind pressures. The appearance and function vary with style, ranging from plain utilitarian walls to ornate balustrades or crenellated forms.

Related terms include balustrade, ledge, merlon, crenellation, and coping.