Pendentive is the term given to a construction element that allows a dome to be placed over square or rectangular spaces. Pendentives are triangular segments of a sphere that spread at the top and taper to points at the bottom, thereby enabling the continuous circular or elliptical base needed to support the dome. The horizontal curve of the dome’s base is connected directly to the vertical curves of the four supporting arches on each corner. Where the curve of the pendentive and dome is continuous, the vaulting form is known as a pendentive dome.
The pendentives receive the outward force from the dome’s weight and concentrate it at the four corners where it is directed down the columns to the foundations beneath. Prior to the development of pendentives, dome construction either demanded that the supporting structure was round, such as in Rome’s Pantheon, or were supported by corbelling or the use of squinches (a construction filling to form a base) in the corners of a room that allowed the dome to sit on top of four arches. Both of these methods limited the possible width and height of the dome. By directing force away from the walls, pendentive domes could be constructed much larger and higher.
The Romans were the first to experiment with pendentive domes in the 2nd-3rd century AD. They saw the supporting of a dome over an enclosed square or polygonal space as a particular architectural challenge.
Byzantine architects perfected the construction methods, and as a result pendentives are a common feature of Islamic architecture, often used with delicate ribbing. Pendentive domes were commonly built for Orthodox, Rennaissance and Baroque churches, in particular in Roman Catholic Europe and Latin America.
 Related articles on Designing Buildings Wiki
- Barrel vault.
- Classical orders in architecture.
- Conoid shell.
- Flying buttress.
- Folded plate construction.
- Geodesic dome.
- Hagia Sophia.
- Hyperbolic paraboloid.
- Millennium Dome.
- Portal frame.
- Shell roof.
- The development of structural membranes.
- The history of fabric structures.
- Types of dome.
Featured articles and news
Read about RSHP's British Museum extension which has been shortlisted for the 2017 Stirling Prize.
Read our introductory article to building a house extension.
More updates from DCMS about the large-scale testing of cladding systems and the number of buildings affected.
UandI secure resolution to grant planning consent for major new regeneration project.
IHBC article considers how heritage is dealt with when infrastructure schemes are authorised.
It was the tallest structure in the world for 3,800 years, but to this day the exact construction techniques are a mystery.
Shortlist for the industry's most coveted award announced.
Government responds to Mark Farmer's review of industry, rejecting the call for a levy on clients.
Peter Hansford to examine what wider lessons can be learned from the fire.
Every project is subject to uncertainty. How can construction better understand uncertainty for performance improvement?
MAD Architects reveal their designs for a futuristic campus for electric car manufacturer.
Homebuyers could borrow more with better forecasting of energy bills, according to industry consortium's new report.
Read our introductory article on carbon capture and storage.