Anatomy of a Window: How the Parts of a Window Work
Some parts of a window are more prominent than others. Here are the ones you need to know.
Getting to know the parts of a window can help you better understand how to operate and clean it your windows, and communicate trouble spots if your window needs maintenance or warranty service. Start by learning the four main components of a window, and use our window parts diagram to boost your home maintenance knowledge.
4 Major Components of a Window
Every window requires four components: a frame, sashes, spacers, and glass. Scroll through the slides and read more below to learn why each of these components of a window is essential to its performance and durability. The window parts diagram below illustrates where to find each component in your window.
What is a Window Sash? And Other Common Window Anatomy QUestions
What is a Window Sash?
The window sash is the part of the window you use most often. When you open or close a window, the sash is the part that moves up and down in a double-hung window, side-to-side in a slider, or cranks open or closed in casement windows.
A window sash is comprised of top and bottom rails, and vertical components called stiles. Double-hung and slider windows have two moveable sashes, while single-hung windows, casements, and other window types have only one sash.
Sashes must resist warping so they move smoothly within the frame, and should also be insulated to offer energy efficiency.
More About Window Glass
As the largest window component, glass seems simple but has several factors that contribute to its functionality. Here are some window glass terms you should know:
- Glazing – Refers to the glass components of a window.
- IGU – Insulated Glazing Unit. The IGU includes the window’s glass panes, the spacer, and the inert insulating glass between the panes. Together, this IGU assembly sits inside the window sash.
- Inert Gas – Most IGUs are filled with an inert gas, either argon or krypton, between the two panes of glass. Inert gases are denser than air, which prevents heat loss through the window glass, improving the window’s overall energy efficiency.
- Low-E – An abbreviation for Low-Emissivity. Low-E refers to a coating that is factory-applied to the glass panes. Low-E coatings improve a window’s energy efficiency by reflecting sunlight away from the window, and also help prevent UV rays from fading or damaging your interior finishes.
Understanding the Window Seal
The connection between the spacer and the glass panes is called the seal. Super strong adhesive creates the window seal, which is essential for keeping the window’s insulating gas between the panes of the IGU. Window seals usually deteriorate or fail after 5 to 7 years, causing fogging (pictured here), and reducing the effectiveness of an energy-efficient window.
Seal failure is a common window problem, but is usually left out of window warranties. Look for a company like Improveit with a lifetime warranty that covers seal failures.
Handy Window Parts Diagram
Get to know the parts of a window! These interior and exterior window parts diagrams help you understand how your window works, inside and out. Have more questions? Reach out to Improveit for a free window consultation and see how Performax54 windows work up close and personal!
Anatomy of a window: Other essential parts of a window
Round out your window parts vocabulary with this extensive list!
Head – The top horizontal piece of the window frame.
Jambs – The vertical sides of the window frame.
Sill – The bottom horizontal piece of the window frame
Stiles – The vertical side pieces of the window sash.
Rails – The horizontal top and bottom pieces of the window sash.
Check Rail – On a double-hung window, the check rail is where the bottom rail of the top sash, and the top rail of the bottom sash meet across the middle of the window. This is usually where the sash lock is positioned.
Mullion – When multiple windows are combined into one unit, such as for a bay or bow window, mullions are the structural components that hold these windows together.
Screen – The woven mesh that covers a window opening. Window material is stretched across its own frame, which sits in a channel in the window sash. Window screens can often be removed or slid out of the way for cleaning. Window screens should never be considered a safety element. Refer to “safety stops” below to learn more.
Weep Hole – Small holes in the across the exterior side of the window sill from which rainwater is evacuated from the frame.
Lift – Running horizontally along the bottom rail of a double-hung window sash, the lift allows you to grip the window to open it. On a slider window, the “lift” will be positioned vertically.
“Very, very pleased with the installation of our windows. Service tech was very knowledgeable on his work and answered all my questions and concerns. He was very, very professional. His eye for details showed in his work.”
– Ken B., Louisville, KY
Anatomy of a Window: Performax54 Special Features
Foam Insulation – Performax54 windows feature foam insulation that fills every nook and cranny of the window frame. This excellent insulation minimizes heat transfer through the window frame.
I-Beam Construction – Window frames must be structurally sound, so Performax54 window feature I-Beam construction that guarantees the frames won’t warp, bow, or sag, and helps the frame withstand expansion, contraction, and settling that happens with all homes.
SolarGold Spacers – The non-metallic SolarGold spacers in Performax54 windows are designed to seal out energy loss 72% better than standard spacers. The three hollow Air Cell Technology channels that run throughout SolarGold spacers are exclusive to Performax54 windows, and minimize warm-edge glass temperatures to reduce heat transfer.
Thermostat Glass – This smart glass technology in Performax54 windows works with the sun to maximize your energy efficiency. Strategic application of Low-E coatings reflect heat away from the window in the summer so your air conditioner doesn’t have to work overtime. In the winter, Thermostat glass allows low-angle sunlight to penetrate the glass, passively heating your home and reducing the heating load for your furnace.
Fusion-Welded Frames – While some windows are mechanically fastened with screws, Improveit’s Performax54 windows feature fusion-welded frames. This means the frames are assembled in the same manner as the steel frames from skyscrapers. Through the process of fusion welding, the welded seams on vinyl windows actually become stronger than the vinyl itself.
FlexScreen Window Screens – All Performax54 windows come with FlexScreen brand window screens, which effortlessly flex for easy removal and replacement. Backed by a lifetime warranty, every FlexScreen fills your entire window so you’re protected from pests and debris any time your window is open. And FlexScreen’s thin edge disappears inside the window frame so it never impedes your view.
Window Accessories, Additional Terminology, and Other Parts of a Window
Crank Handle – Casement windows feature a crank handle for operation. Mounted on the frame, turning the crank handle opens and closes the vertical casement window sash.
Fixed Window – Inoperable windows, including picture windows and architectural windows, are often called “fixed” windows because they are fixed – not moveable – within their frames.
Grids – Window grids are decorative elements that give the appearance of dividing the window into smaller sections. Sometimes called “grilles” or “divided lites,” window grids are available in multiple patterns, including colonial, prairie, and diamond, to suit the style of your home.
Safety Stops – Safety stops provide security when opening double-hung and slider windows. On double-hung windows, the safety stops are mounted on the stiles of the upper sash, approximately 4 inches above the check rail. When in the open or active position, safety stops prevent the bottom sash from raising more than a few inches. This allows the window to be open for ventilation without creating a fall hazard from inside the home, or allowing unwanted access from the exterior of the house.
Sash Lock – All operable windows should have a sash lock mechanism that locks the sash inside the frame for security. On double-hung windows, the sash lock is mounted on the check rail, while casement windows have sash locks either on the top and bottom rails, or the vertical stile where the sash meets the frame.
Tilt Latch – On tilt-to-clean double-hung windows, two tilt latches are situated on either side of the top rail of each sash. Disengaging these latches releases the window sash from the frame to tilt in for easy cleaning.
Window Components: People Also Ask
Vinyl windows are easy to clean with mild household cleaners or soap and water. Follow the instructions in the link below for easy cleaning steps. For wood windows, be sure to follow your manufacturer’s instructions on which wood-friendly cleaners to use.
Yes! Some of the window components mentioned on this page are specific to tilt-in windows, in which the sashes release from the frame and tilt into the room. This allows you to clean the exterior of the window without going outside, and is especially helpful for cleaning second-story windows.
Discussions about dual- and triple-paned windows are referring to the number of glass panes in the window’s IGU. Dual-paned windows have two panes of glass, while triple-paned have three. Each have their benefits, though triple-paned windows can be substantially more expensive.
Learn More: Product Comparison: Dual vs. Triple Pane Windows
There are about 10 different window types to choose from for your home. Double-hung windows are the most popular nationwide. The 10 window types in the Performax54 line include:
- Double-Hung
- Casement
- Slider
- Picture
- Architectural
- Awning
- Hopper
- Bay
- Bow
- Garden
Learn More: Replacement Window Styles
Whether you’re just learning this window terminology or have a long history of home improvement expertise, Improveit is happy to discuss your window project and provide all the education you need. Reach out today for a free consultation.
