Window Sash or Sill? Window Terminology 101

Whether you’re a weathered DIYer or just beginning your home renovation journey, knowing basic window lingo, like understanding the difference between a window sash and window sill, will help you navigate future projects and become a more seasoned homeowner. Common single-hung, double-hung, and sliding windows have many main components, but always remember that glass is 80% of your window — so be sure to invest in quality products when upgrading. 

Anatomy of a Window  

The master frame supports the entire window system — it encompasses the head, jambs, sashes, and sill. The window sash frame holds the panes of glass to the master frame (depending on style of window)  and can be removed for cleaning. Jambs are the vertical sides of the windows, while the window sill is a horizontal component that is essential for keeping water from pooling at the base of your window. 


In single-hung windows, the bottom window sash can move up and down while the top pane is inoperable. The top and bottom sashes can both move in double-hung windows, which are easy to clean because they tilt out for ease-of-use. Most sliders, including single-slide, move side-to-side but have a fixed pane on one side. Double sliders can also lift out for cleaning. 

Low-E and Powerful Insulators 

To create an energy-efficient window, manufacturers use smart tints and gases to help reduce heat transfer between your home and the outdoors. Low-E is short for “low emissivity” — meaning that the glass is tinted with a thin film that assists with heat control without blocking natural light. Argon and krypton gas are two powerful insulators that regulate the temperature of your home between the panes of glass. They are six and 12 times thicker than air, which helps block thermal energy from traveling through your window. Both argon and krypton gases are safe, odorless, colorless, non-toxic, and non-flammable. Triple pane windows are usually the most energy-efficient. 

We’re happy to help you begin your home renovation experience by walking you through window styles, benefits, and — of course — terminology. Call us today for a free in-home consultation to start saving big!


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