dome

A dome is a rounded architectural element that forms the roof or ceiling of a building, typically a hemisphere or segment of a sphere. It defines interior space without columns and is carried by a supporting drum, pendentives, or a masonry shell.

In design, domes behave as compressive shells; their geometry directs weight to the base, allowing wide, open interiors. Traditional domes were built from brick, masonry, or concrete; modern versions may use steel frames with concrete or metal cladding, or lightweight panels in geodesic configurations.

Historically, domes appear in the ancient Mediterranean and Near East. The Pantheon in Rome (c. 126 CE) is a landmark example of a large unreinforced concrete dome. Byzantine architects advanced dome construction, culminating in Hagia Sophia. The Renaissance produced influential domes such as Brunelleschi’s dome for Florence Cathedral.

Types and variants include hemispherical domes, pointed or ogival domes, and onion domes, plus polygonal domes that approximate a sphere. Geodesic domes, designed by Buckminster Fuller in the 20th century, use a network of triangles for strength and light weight.

Domes remain common in religious architecture, civic buildings, planetariums, sports arenas, and mosques. They offer expansive interior spaces, distinctive acoustics, and dramatic exterior silhouettes.