Flying buttress

Lore & Background

The flying buttress was developed during late antiquity and later flourished during the Gothic period (12th–16th c.) of architecture. Ancient examples can be found on the Basilica of San Vitale in Ravenna and on the Rotunda of Galerius in Thessaloniki. Architectural-element precursors derive from Byzantine architecture and Romanesque architecture, such as at Durham Cathedral, where arches transmit the lateral thrust of the stone vault over the aisles, hidden under the gallery roof. Early designs, such as at Chartres Cathedral (ca. Later architects refined the design, narrowing the flyers, as seen at Amiens Cathedral, Le Mans Cathedral, and Beauvais Cathedral. Late Gothic buildings featured flying buttresses with flyers decorated with crockets and sculpted figures set in aedicules.

Reader's Guide

The flying buttress allowed outer walls to be less massive and heavy, reducing wall surface and enabling larger windows, often glazed with stained glass. Vertical mass was concentrated onto external buttresses. The system is a two-part composite: a semi-arch extending to a massive pier, providing most load-bearing capacity of a traditional buttress while being lighter and more cost-effective. In Gothic churches, two arched flyers were often applied: the lower resisted lateral thrust of the vault, the upper resisted wind-loading on the roof. Vertical buttresses were capped with pinnacles to provide additional vertical-load support. The Renaissance eschewed flying buttresses in favor of thick-wall construction, but the design was revived in the early 20th century by Canadian engineer William P. Anderson for lighthouses. The flying buttress became a defining factor of medieval Gothic architecture, contributing to open space and light in cathedrals, and creating a sense of coherence and continuity between interior and exterior.

Did You Know?

• The flying buttress is not in contact with the wall at ground level, unlike a traditional buttress.
• Ancient examples of the flying buttress can be found on the Basilica of San Vitale in Ravenna and the Rotunda of Galerius in Thessaloniki.
• In the early 20th century, the flying-buttress design was revived by Canadian engineer William P. Anderson to build lighthouses.