ossature

Ossature is a French noun used to denote the internal framework or skeleton of a system. In architectural and civil engineering contexts, the ossature refers to the load‑bearing skeleton of a building or other structure: a network of elements such as columns, beams, and braces that transfer loads to foundations. The ossature determines the structure's stiffness, strength, and ductility, and may be realized as a steel frame, a reinforced concrete frame, or a timber frame. The distinction is often drawn between a rigid frame (skeleton) and the exterior envelope or cladding, with design focusing on ensuring stability under vertical and lateral loads, such as wind or seismic actions.

In biology, the term is used to describe the skeleton of an organism. The ossature comprises the bones and cartilages that form the axial and appendicular skeleton, providing support, protection for internal organs, and a system for movement. It also serves as a reservoir for minerals and a site for hematopoiesis in bone marrow.

Etymology: from French os (bone); the term has been adopted into architectural discourse to emphasize the internal framework as the "bone" of a building.

See also: skeleton, structural frame, framework.