What characteristic defines frame construction in buildings?

Frame construction is characterized primarily by the use of wood or other combustible materials as the structural framework. This type of construction is commonly found in residential buildings, where the skeleton is formed by vertical and horizontal wooden members that provide support for the walls, floors, and roof.

The use of timber in frame construction allows for greater flexibility and ease in building design, and it is often more cost-effective than heavier, non-combustible materials. The walls in frame construction can be sheathed with various materials to provide insulation and a finished appearance, but the fundamental characteristic comes from the framing itself, which relies on these combustible materials.

Other construction types, such as those made with metal or concrete, or reinforced steel structures, are defined by their use of non-combustible materials, which significantly alters their fire resistance characteristics and construction techniques.