Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. architectural elements
7. [structural elements and components for structural elements]
8. structural element components
9. [balloon and platform frame components]

Anotations

Scope note:

Horizontal members laid across the bottom of an unfinished opening to act as a base during construction of window frames or door frames. For the horizontal members that rest on the foundation at the bottom of a wood structure, use "sill plates."