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. [openings and opening components]
8. openings (architectural elements)
9. [openings by form]
10. [windows and window components]
11. window components
12. [window frames and window frame components]
13. window frame components
14. window sills

Anotations

Scope note:

Window sills in a brick or stone wall, where the sill extends beyond the width of the window opening and with the ends of the sill set in the wall. Distinguished from "slip sills" which are just as long as the window is wide and fit into the walls between the jambs.