Artifacts originally created as part of a building's fabric. Although building components are distinct objects, they function as parts of larger structures rather than as independent units. Building components can be separate, distinct, and generally interchangeable structural, functional, or decorative parts of buildings such as beams, sinks, or architectural ornaments. This classification also includes architectural samples integral to buildings, such as wall sections, staircases, or porches, as well as certain whole-structure building system components such as ventilators or furnaces. Excluded from this classification are parts of buildings that are not integral parts of the structure, such as furnishings or lighting devices, which are included in the Furnishings category