What to Know About Buying Windows

Updated: May 17, 2023

When shopping for windows, you'll find seven basic styles and at least seven important considerations. Knowing these makes you a smarter shopper.

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Even the best windows don’t last forever. That helps explain why the window replacement industry generates an estimated $5 billion in annual revenue.

Whether your old windows need replacing or you’re building a new home or addition, you have plenty of options. Unless you install them yourself, you’re looking at an average cost of $800 to $1,400 per window, depending on type.

Unfortunately, federal tax credits that partially offset these costs expired in 2021. But window design has improved to the point that replacing your old windows with new insulated ones can more than make up for it in energy savings.

Besides providing better insulation, new windows also look better. Frames increasingly incorporate weather-resistant materials like vinyl and composites that last longer than wood. Glass can be treated to filter out glare without inhibiting visibility, and new windows clean more easily.

Seven Types of Windows

The sash is the inner part of the window frame that holds the glass. How it moves (or doesn’t) in relation to the outer part of the frame is the main factor determining window style.


In these, the sash is permanently affixed to the frame. Or it may be absent altogether, with the glass attached directly to the frame. Fixed windows are the easiest to weatherproof.

Bay and garden windows that protrude out from a wall to create an interior space surrounded by glass are fixed windows. So are picture windows, along with translucent windows that incorporate glass tiles or stained glass.


Sliding windows typically have one fixed sash and one that slides horizontally along a track. One edge of the sliding sash tucks into a groove on the frame when the window is closed, and the other is sealed against the fixed sash by a gasket. This type of window typically needs weatherstripping to prevent heat transfer.


A single-hung window has an upper fixed sash and a lower one that slides up and down. When closed, the bottom edge of the sliding sash fits into a groove in the window sill. The top edge seals against the fixed sash.


Double hung windows resemble the single-hung type, but both sashes slide up and down, doubling the available venting area. One handy feature: A release mechanism that lets you to tilt the sashes into the room to clean the outside glass.


One sash of a casement window is mounted on a vertical pivot, which allows it to swing outward. Casement windows often have a crank handle that lets you open them a little or a lot.

Awning and hopper

Like casement windows, awning and hopper windows have sashes that pivot on an axis. But the axis is horizontal instead of vertical.

An awning window pivots from the top and swings outward, letting you keep the window open while it’s raining. A hopper window pivots from the bottom and swings inward, ideal for ventilating a bathroom or basement.


Consisting of multiple narrow panes of glass arranged horizontally like the slats of a blind, a jalousie window opens and closes like a blind via a crank handle. This is the most difficult type of window to weatherproof, but it’s popular in warm climates because it ventilates so well.

Other Types

Other types of windows are variations on one of these seven styles.

A storm window is a fixed window that attaches temporarily to the outside of the window frame for extra weatherproofing.

An egress window, required in finished basements, is a sliding window or one with a fixed-but-removable sash, providing enough space to exit the building in an emergency. It must provide an opening at least 24 inches tall and 20 inches wide, with a total area of 5.7 square feet.

Seven Things To Consider When Buying Windows

Windows are an essential design element of every house, so it’s natural to prioritize aesthetic factors like shape, color and material. They’re important, but can be outweighed by other more practical concerns.


If you’re replacing an existing window, the replacement has to fit in the same space as the original, otherwise installation becomes much more difficult and expensive. It’s best to measure the length and width of the original and go with that.

If you’re installing a new window, it has to fit in the rough opening created by the framing. For wiggle room, allow 3/4-in. to 1-in. of space from top to bottom and from left to right.


Double- and triple-pane windows cost more than single-pane, but they insulate so well you’ll recoup the extra bucks in energy savings in no time. Triple-pane windows are the most expensive. Unless you live in an area with extremely frigid winters, they aren’t necessary.


Vinyl frames and sashes are the most popular because they’re lightweight, relatively inexpensive and maintain their appearance indefinitely. The downside is, you can’t paint them. (Well, you can, but we don’t recommend it.)

While some people love the clean look of vinyl, others prefer composites, a combination of fiberglass and plastic that mimics the look of wood. If real wood is your touchstone, you can find plenty of wood-framed windows out there. Just be prepared to pay a premium.

If you just need utility windows for the garage or an enclosed porch, inexpensive aluminum is your best bet.


Vinyl and composite frames tend to wear better and last longer than wood. For safety, choose laminated or tempered window glass over standard. That way, when your neighbor’s kid slams a home run through your window, you won’t be cleaning shards of glass off the floor.


Double-hung, sliding and casement windows you can clean from inside are best for upper stories. If condensation is a problem in your house, stay away from unpainted wooden frames, which can discolor and rot from excessive moisture.


Ground-floor windows should be lockable, with safety glass that’s tough to shatter.

Energy efficiency

Double-pane windows, with an argon-filled vapor barrier between the panes, provide better insulation and energy savings than single-pane windows. Triple-pane windows are even more energy-efficient, but costlier.


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