Parts of a Window – A Diagram and Guide for Homeowners

How can you enhance your home’s appearance, boost its curb appeal, and increase its energy efficiency? You can achieve all of this by replacing old windows with new ones. However, before you go shopping for windows, it’s important to know what you’re looking for.

This begins with understanding the various components, thereby ensuring that the manufacturers and installers you choose will provide the kind of windows (and appearance) you want and desire. In the following guide, we will review the parts of a window, so you can make an informed buying decision.

What are the Parts of a Window Called?

Balance

The balance is the mechanical device used to counterbalance the sash’s weight during both opening and closing – be it a single-hung window or a double one.

Frame

The window frame supports the whole system and is made up of the sill, jamb and head.

Glass

Inside the window frame is a piece of glass to keep the elements out and the cool/warm air in.

Head

This part of the window is located at the top of the frame and is horizontal.

Jambs

The vertical part of the window create the window frame’s sides.

Jambliner

These are the strips added to the window sides to ensure a snug fit for the sash.

Lift

This involves a handle, which lifts the lower sash.

Rails

A double-hung window has three rails. The upper and lower ones are situated on the horizontal part of the sash. In the middle is the check rail. It’s where the upper piece of the lower sash links to the bottom piece of the upper sash.

Sash

The sash is what holds the window in place even while it’s moved.

Sash Lock

This locking apparatus clicks with the sash lock strike to eliminate any rattling.

Sill

Often called the stool, it’s the primary horizontal part that makes up the bottom part of the frame.

Weep Hole

These are located on the window sill and are individual openings that ensure condensation and water escapes.

Other Parts of a Double Hung Window

Casing

This is the window’s ornate frame or molding that closes up the space between the wall and jamb/frame.

Exterior Aluminum Cladding

A window’s outer part is generally encased by extruded aluminum and has a factory finish to protect the window from the elements.

Fixed Panel

This part of the window doesn’t move and is more of a sidelight or accent to it.

Grilles

This is more of an ornate piece of the window, giving the appearance of several glass panes due to the visual division of window panels.

Hinged Glass Panel

A glass panel will open inward, letting you quickly access the grilles, shades and blinds found between the panes.

Lock Handle

This is the apparatus found on the window jamb.

Mullion

This is an integral piece that links at least two windows together.

Operator

This crank-operated device will open and close a window.

Screen

This is a woven mesh of fiberglass, metal or plastic that spans the window opening to ensure air passes through.

Weatherstrip

This strong piece of material will cover the joint between the frame and sash to eliminate air leaks and keep water from getting in.

Additional Structures That Make Up a Window

Apron

This decorative trim is located under the window stool, giving the window interior a sleek, modern design.

Hinges

The kind of window you have determines the hinges’ location. If you have a casement window, the hinges on the jambs of the non-opening side. For an awning window, the hinges are located on the frame head as the window opens up from the window. On hopper windows, the hinges can be found on the sill, as the window will open from the top.

Spacers

Spaces located on the window frame bottom and top will hold at least two glass panes together. These help to insulate the window.

Common Materials Used On Windows

Fiberglass

The window sash and frame are made up of five-layer fiberglass material.

Vinyl

These are extruded stiff PVS on the exterior and interior sash and frame surfaces.

Wood

Solid wood makes up the window sash and frame.