buttresses

Buttresses are architectural supports that resist lateral forces pushing a wall outward. They transfer such thrusts to adjacent structures, providing stability for tall walls and large openings, especially in vaulted buildings.

There are several forms of buttresses. External buttresses stand outside the occupied space and connect to the wall to reinforce it. Flying buttresses, a hallmark of Gothic architecture, consist of an arched element that rises from a separate exterior support to channel thrust from the wall to a distant pier. Internal buttresses perform a similar reinforcing function inside the building.

The primary purpose of buttresses is to counteract the lateral thrust generated by vaulted ceilings and heavy roofs. By directing these forces away from the wall, they allow thinner walls and larger windows, enabling taller, more luminous structures.

Historically, buttresses appear in ancient and medieval architecture and became a defining feature of Gothic cathedrals in the 12th to 16th centuries. The development of pointed arches and rib vaults increased outward thrust, which the flying buttress helped manage while preserving interior space for windows.

Materials and variations vary by period and region. Traditional buttresses are made of stone or brick; modern examples may use reinforced concrete or steel where appropriate. While primarily structural, buttresses also contribute to the exterior silhouette of a building and can be decorative elements in some designs.

Notable examples include Gothic cathedrals such as Notre-Dame de Paris and Chartres Cathedral, where buttresses are integral to both engineering and architectural expression.