Glossary – Wooden Sliding Sash Windows

1. Top Sash: The upper part / sash / opener of a sliding sash window

2. Bottom Sash: The lower movable part / sash / opener of a sliding sash window.

3. Mid Rail/Meeting Rail: The horizontal bar that separates the top sash from the bottom sash in a sliding sash window. When the window is closed, this rail typically meets the corresponding rail of the opposite sash.

4. Glazing Bars: Thin, decorative strips of material that divide a window sash or frame into smaller panes, adding architectural detail.

• Astragal Bars: Decorative bars applied to the surface of a window, simulating the appearance of individual smaller panes, characteristic of Georgian architecture.
• Georgian Bars: Narrow bars or mouldings dividing individual panes of glass within a window or door, enhancing the traditional aesthetic.

5. Box Sash Frame, Outer Liner: The outer frame of the sliding sash window that houses the sashes and counterweights. It provides support for the window and openers and houses the sliding mechanism.

6. Stiles: The vertical components of the sash frame that run along the sides of the window. They provide the window frame support and hold the openers/sashes inside the frame.

7. Decorative Horns: Small projections or extensions typically found at the top corners of the top sash in traditional sliding sash windows. They are primarily decorative but historically were also functional in preventing the sash from being overextended.

8. Top Rail: The horizontal top edge of each sash that runs along the top of the window frame.

9. Bottom Rail: The horizontal bottom edge of each sash that runs along the bottom of the window frame.

10. Cill: The horizontal ledge at the bottom of the window frame that extends outward from the wall, often serving as a shelf or decorative feature.

11. Box Sash Frame, Head Outer Liner: The horizontal top part of the outer frame of the sliding sash window. It forms the upper boundary of the window frame.