Windows frames come in a number of different materials, including wood, vinyl aluminum, fiberglass and composite plastic.

When choosing between the types of materials, it’s important to take everything in consideration.

Some things to keep in mind when choosing replacement windows for your home include the following.

Aluminum-frame windows offer the low cost and low maintenance of vinyl versions; they're also durable. The major drawback to aluminum-frame windows is their metal frame-they conduct heat easily, earning them a high U-value. (Higher is not better here — the higher the U-value, the more heat a frame loses.) Compared with vinyl or wood frames, which fall within the 0.3 to 0.5 range, aluminum frames can have a U-value as high as 2. They also tend to feel cold to the touch and are prone to condensation.

Those drawbacks make aluminum-frame windows suitable only for warm climates where cooling bills are greater than heating bills. If you decide to install aluminum windows, be sure the ones you order are equipped with a thermal break in the frame — usually a strip of plastic or rubber that keeps the inside and outside of the frame separate in order to help limit heat conductivity.

Vinyl-frame windows are the most affordable — as little as half the price of comparable wood-frame versions. Many also come with intricate decorative molding options that mimic the look of real wood, making them just as appealing and much more cost efficient.

They're also especially energy efficient, thanks to a honeycomb of chambers that boost insulating ability by trapping air, and can be built to fit any size opening. And unlike wood, they never need repainting or sealing, though colors are limited. Vinyl windows can be fit snuggly to insulate your home for years to come.

Vinyl-frame windows first appeared in the 1970s when small fabricators produced custom replacement options in sizes not offered by manufacturers of stock wood windows. Today,
nationwide companies such as Owens Corning and CertainTeed offer a variety of units in stock and custom sizes. Even traditional wood-window companies now offer vinyl -frame replacement
lines. Vinyl Windows can be built to fit any size opening. Vinyl replacement windows have much quicker turnaround times, meaning that you get your windows when you need them.

When shopping, look for a uniform color throughout the frame. Also look for joints that are heat-welded rather than joined with screws or other fasteners. You can expect a two - to six-week
wait if you order custom units.

Certain manufacturers have styles that are available with a variety of glazing systems to help reduce heating and cooling bills.

Wood-frame windows are slowly losing their market dominance to vinyl, though they're still considered the gold standard by many professional installers and homeowners. They're strong,
beautiful and relatively energy efficient. As might be expected, good ones also cost the most. The knock against them is maintenance: They must be painted or stained periodically to look good, maintain its beauty and function, and remain protected from the elements. While wood is a natural insulator, seals can wear away over time leaving your home susceptible to drafts and leaks.

Since most wood windows need to be custom made and fitted, it can take much longer for them to be installed in your home.

Clad-wood windows are providing a great alternative to the maintenance issues of all wood windows. Some manufacturers address that required upkeep by cladding the wood with vinyl or aluminum. The result is a tough, maintenance-free exterior and a
natural-wood interior that you can paint or stain. These advantages mean clad-wood windows usually cost more than ordinary wood.

When shopping for wood windows, look for easy operation and tight-fitting corners. Be sure any exposed wood is free of blemishes and that finger joints aren't visible.

Fiberglass and composite-frame windows are the newest options. Made from materials similar to those on car bumpers, both are strong, maintenance-free and more energy efficient than vinyl. And at a price roughly between vinyl and
wood, they're also affordable. Some manufacturers make these units so that they can be painted to suit your taste, something you can't do with vinyl windows. As with vinyl windows, look for a uniform color throughout the frame and joints that are heat welded rather than joined with fasteners. And, whichever window you're considering, don't go by material alone. Check out the locks, cranks and lifts. They should be easy to use and feel comfortable in your hand. A quality window has quality hardware.