Flowers on a windowsill

Window Buying Guide

Finding energy-efficient windows has become easier, as insulating features such as heat-reflecting low-E coatings and argon gas between panes have become more standard. You'll also find new options and extras, including fiberglass window frames. Use this buying guide to make your selection.

Types

Windows vary in material and design. Wood window frames account for about half of all replacement-window sales, with all-vinyl and all-fiberglass accounting for most of the rest. All the windows we tested are double hung, with two sashes that slide vertically. But some homes or special rooms call for styles like awning or casement windows. Here are the types of windows to consider.

Wood-frame and fiberglass-frame windows

Wood-frame window
Wood-frame and fiberglass-frame windows

These windows were our top overall scorers. On wood-frame windows, the wood is clad in vinyl or aluminum for durability. The fiberglass-frame windows are all-fiberglass. The major brand wood- and fiberglass-frame windows we tested excelled at keeping out cold air and rain when they were new. After we subjected each window to a week's worth of extreme temperature swings that that made their components flex, expand, and contract, the best models showed little or no loss of performance.

 

Vinyl-frame windows

Vinyl-frame window
Vinyl-frame windows

Although relatively inexpensive and maintenance-free, vinyl windows tend to leak air a bit more. Also, they lack the visual appeal of wood, and they can't be painted or stained, so they may be inappropriate for an older home.

 

Awning-style windows

Awning-style window
Awning-style windows

They're hinged at the top and open outward. They leak less air than sliders and single- or double-hung windows because the sash presses against the frame to close. They also offer better ventilation than sliders of the same size and can be left open when it's raining because they deflect rain during storms. But screens can be placed only on the inside.

 

Casement-style windows

Casement-style window
Casement-style windows

They're hinged at one side, like a door, and usually open outward. Like other hinged windows, you typically get less air leakage because the sash presses against the frame to close. They're easy to clean and also offer better ventilation than sliders of the same size because they open to the full glass area. You can position them to catch passing breezes. Two drawbacks are that screens can be placed only on the inside and most open using cranks that must be operated manually.

 

Fixed windows

Fixed window
Fixed windows

These are used where lighting but not ventilation is important. Pros: These windows are airtight and are available with decorative glass accents or in unusual shapes. But fixed windows don't open, so they provide no ventilation.

 

Hopper-style windows

Hopper-style window
Hopper-style windows

The opposite of awning windows, they're hinged at the bottom and can open either inward or outward. They're often installed above a door or another window, protected by eaves. You get less air leakage than with sliding and single- or double-hung windows because the sash presses against the frame to close. But screens can be placed only on one side.