Let’s Talk Window Terms

If you’re ready to window shop, let’s talk window terms. Double hung or single hung? Replacement or new construction? Since these are just two basic questions when you’re looking for new windows, we thought this would be helpful information for you to check out.


Let’s Talk Window Terms

  1. Frame – Structural support for a window consisting of head, sill and jamb.
  2. Head – The main horizontal piece at the top of the window frame.
  3. Jamb – The main vertical pieces forming the window frame. The top, sides, and bottom of the window frame (includes the head) can also be considered as the jamb.
  4. Stiles – Vertical supports of the sash at the sides of a window.
  5. Rails – Horizontal strips connecting the stiles at the top and bottom.
  6. Sill/Stool – A horizontal ledge located under the bottom of a window. This piece commonly juts out slightly from the wall.
  7. Sash (upper/lower) – The frame along a window consisting of stiles and rails; holds the glass in place. The top is the upper sash; the bottom is called the lower sash.
  8. Grid/Muntin/Grille – A strip which separates panes of glass. Can be placed outside (for decoration) or inside the window, holding the glass in place. It’s quite common for newer windows to have grids on the inside, allowing for easier maintenance.
  9. Apron – A horizontal board under the sill and attached to the wall.
  10. Casing – Decorative moulding surrounding a window. It hides any space between the wall and window.
  11. Glazing – The thickness of the glass in the frame.
  12. Hardware – Can include sash locks; handles for casement windows
Let's talk window terms

New construction windows with grids.

A Little More About Windows

So, now you know about the parts of a window. In addition, there are many styles of windows to consider. Single hung and double hung are most popular. The difference between the two? The upper sash of a single hung window doesn’t move, only the bottom sash can move up and down. A double hung window allows for both the upper and lower sashes to move.

As the name implies, new construction windows are best used for new homes where framing is done as the home is being built. A replacement window will fit into a space where a frame is already in place.

In addition to knowing the rough opening for the size of the window, consider an option such as LowE glass. LowE, or low-emissivity, glass minimizes the amount of infrared and ultraviolet light coming through the glass, without lessening the amount of light passing through. And a tilt-in sash is a great choice for cleaning windows. Also, grids and locks are other options.


Finally, visit your nearby Builder Surplus store in Rhode Island, Connecticut or Massachusetts. Come in and talk with our associates about windows and what you may need for your home improvement project.