The framing material of any built object is the predominant material used in its framing system or load-bearing skeleton. Materials are usually chosen for their ability to carry loads, to resist bending or breaking under winds and earthquakes, and for their economy and availability.

Framing elements include columns, shear walls, beams of various kinds, and structural floorplates. They do not include facades or other finishing materials, foundations, or interior partitions that can be shifted or removed without affecting the structure's integrity.

When more than one material is used in a structural frame, there are two basic configurations that determine which material should be assigned:

In the first case, different parts of the frame are built using entirely different materials - for example, a frame using material "A" is stacked on top of a lower frame using material "B" - or a building with material "A" gets a new addition using material "B". In this case, both materials should be selected individually.

In the second case, two different materials are integrated into one frame (at the same floor levels), and act together to counter gravity and stresses. Usually one material (such as steel or wood) has very good tensile strength - it is not brittle, and can span long distances - and the other material (such as concrete or stone) has very good compressive strength - it cannot be bent or squeezed out of shape. When two materials are joined together in this way, the structure has a mixed frame.