In a previous blog we defined the terms used by the National Fenestration Rating Council on their window stickers. Recently we realized that we haven’t talked about some of the widely used terms to describe the parts of the windows. If you’re considering new windows soon, knowing these terms will help you make the best purchase decision.

New Construction Windows and Replacement Windows Differ

If you are building a new home, new construction windows make sense. However, if you’re replacing your windows, most of the time you’ll need replacement windows. This is because the design of the two differ. A replacement window is meant to fit into an existing frame. A new construction window is nailed into the home’s framed window opening. The only exception when new construction windows may make more sense is if you’re replacing both the siding and windows at the same time with the same company.

Window Frame & Sash

We’ve heard people mistakenly refer to the window itself as the window frame. However, the frame is the part that attaches to the home. Some of the frame is covered by siding or trim. The sash is generally considered the part of the window that opens and closes. The exception is in single hung windows where the bottom sash is the one that opens and closes and the top sash is stationary. Also, a picture window has a single sash.

Grids, Grilles, Muntins

These words are often used interchangeably, but they are different.

  • Muntins – Almost all old wood windows have actual muntins. The pattern in the window actually holds separate pieces of glass. Sometimes these windows are referred to as divided light windows.
  • Grilles – Window grilles are often mounted to the outside of the window to make removal, This makes cleaning entire pane of glass easier.
  • Grids – Most common in new and replacement windows today, grids are dividers between the two pieces of glass.

Admittedly, some window manufacturers and window companies use the terms grilles and grids interchangeably.


Your window hardware includes the handle to open the window, the locking mechanism and any other attachments on the window itself. You may have the option to choose from various finishes for your window hardware.

If you’re looking for replacement windows from a company who will clearly answer your questions, provide quality windows and make the process simple and affordable, call or text Affordable Replacement Window Systems today. You can reach us at (817) 264-6509 or fill out our contact form and we’ll call you.

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