dome - Characteristics, Cupola, Famous domes, Xanadu House

Any curved termination to a building which is circular in plan; also called a cupola. The classic Renaissance dome is a slightly pointed hemisphere, as in St Peter's, Rome. Other shapes range from the flatter dish of the Pantheon in Rome to the bulging onion of St Mark's, Venice. The word also describes the whole architectural ensemble, including the cylindrical area (drum) below and the lantern above the actual dome itself.

For other uses, see Dome (disambiguation).

A dome is a common structural element of architecture that resembles the hollow upper half of a sphere. Though the oval dome is identified with churches of Bernini and Borromini, the first oval dome was erected by Vignola for a small chapel, Sant'Andrea in via Flaminia often called Sant'Andrea del Vignola, which was commissioned in 1552 by Julius III, and finished the following year , the biggest oval dome was built in the basilica of Vicoforte by Francesco Gallo.

Domes that have been disproportionately influential in later architecture are those of the Great Stupa in Sanchi (actually, a solid mound with stone facing), the Pantheon in Rome, Hagia Sophia in Istanbul, and the Dome of the Rock in Jerusalem. In Western architecture, the most influential domes built since the Renaissance have been those of St. Peter's Basilica in Rome and Jules Hardouin-Mansart's dome at Les Invalides in Paris. The dome of St. Paul's Cathedral in London was the inspiration for the United States Capitol in Washington, which in turn inspired domes of most of the US state capitols.

A cathedral is often referred to as a duomo in Italian or "dom" in German, not because so many are crowned with crossing domes over the space where transepts intersect the nave, but from the latin "domus", house, in this case the "domus dei", the house of God.

In the 20th century, thin "eggshell" domes of pre-stressed concrete by architect-engineers such as Nervi opened new directions in fluid vaulted spaces enclosed beneath freeform domed space which now might be supported merely at points rather than in the traditional constricting ring.

Characteristics

A dome can be considered as an arch which has been rotated around its vertical axis. Larger domes built after Brunelleschi's dome that triumphantly spanned the crossing of Santa Maria del Fiore, the duomo of Florence, have all been built as double domes, with inner and outer shells.

The concave triangular or trapezoidal sections of vaulting that provide the transition between a dome and the square base on which it is set and transfer the weight of the dome are called pendentives. (A less sophisticated version of a pendentive is a squinch.) Under the dome illustrated at left, the pendentives bear circular medallions in bas relief.

A pendentive is a constructive device permitting the placing of a circular dome over a square room or an elliptical dome over a rectangular room. The pendentives, which are triangular segments of a sphere, taper to points at the bottom and spread at the top to establish the continuous circular or elliptical base needed for the dome. Pendentives were commonly used in Renaissance and baroque churches, with a drum often inserted between the dome and pendentives.

Many domes are topped by a lantern, a structure with openings (or windows) to admit light in the cupola.

Many sports stadiums are domed, especially in climates that have widely-variable summer and winter weather. A major improvement to the domed stadium was accomplished with the construction of SkyDome in Toronto, Ontario, the first domed stadium with a retractable roof.

Saucer dome

A saucer dome is the architectural term used for a low pitched shallow dome.

Gaining in popularity from the 18th century onwards, the saucer dome is often a feature of interior design, viewed from below it resembles the shallow concave shape of a saucer.

Onion dome

The onion dome resembles more than half of a sphere, exemplified by Saint Basil's Cathedral in Moscow and the Taj Mahal.

Dome theater

Structures designed to fit a panoramic movie format.

Cupola

A cupola is a dome-shaped ornamental structure located on top of a larger roof or dome, often used as a lookout or to admit light and provide ventilation.

Famous domes

Listed in order of their completion:

c. 1250 BC - Treasury of Atreus, Mycenae, Greece (a corbel dome). 3rd century BC - The Great Stupa, Sanchi, India (not a true dome, as it is solid throughout). 691 - Dome of the Rock, Jerusalem, Israel. 1312 - Dome of Soltaniyeh, Iran. 1989 - Stockholm Globe Arena - Ø 110 m 1989 - SkyDome aka Roger's Centre , Toronto, ON, Canada. 2000 - The Millennium Dome, London, England (not a true dome, as it is not self-supporting).

Xanadu House

The Xanadu House was a home that used the concept of domes heavily in its shape and design.