Four years ago, Tony Tucker decided the time had come to look into replacement windows for his Takoma Park, Md., house. The original windows didn't keep the 70-year-old Cape Cod snug, even after the installation of newer storm windows. Some windows were permanently stuck shut; others had to be propped open.

— Joel Sartore/National Geographic/Getty Images

See also: Rules of thumb about repairing or replacing.

Tucker was right to consider new windows. Experts recommend replacements when windows are leaky, tough to operate or have only one pane of glass (aka single-glazed). New materials and technologies have brought to market products that pay for themselves over time by reducing energy bills and eliminating the cost of repainting every few years.

But after doing some research and meeting with sales reps, the Harvard-trained health care analyst's project stalled. Choosing windows and a vendor turned out to be "much more complicated than the health care debate," he says. "There was a lot more to learn, more people I could have talked to. But it was already hard to sort out the information I'd gathered. I just didn't want to get ripped off."

If replacing windows is not quite navigating Medicare Part B, it does confront consumers with a daunting array of options — in three categories: the window system, the material it's made of and the type of glazing. Your home improvement goals and budget will shape your choices in each category.

System
Choosing the right window system depends on how much of the window you need to replace to solve your existing problems. There are at least three different systems: sash replacements, sash replacements in a unitary frame and "prime windows," or full window units with structural frames and sills like those used in new construction. If your old window frames are rotted and you see signs of water damage in the wall framing, you'll probably want to go with prime windows (be sure to find the source of the leak and fix that first). If, on the other hand, the frames are sound and square, you may be able to get away with simply replacing the sash.

Material
Replacement windows come in vinyl, aluminum, wood, clad wood or fiberglass. Each looks and performs differently, and cost differences among materials vary widely. As a general rule, the most expensive choice is clad wood, which combines a traditional look with low maintenance and energy efficient performance. By contrast, vinyl windows, which offer good energy performance but usually look heavier and lack traditional details, tend to cost the least.

Glazing
Double-pane insulating glass is now standard with most replacement windows, but you can add special features: low-E coatings and gas fill can enhance energy performance, while other choices address noise control, safety, security, privacy and reduced cleaning. All, however, come at a price.

High Anxiety Sales Approach
Determining the type of replacement windows you want is in many ways the easiest part. Finding a dealer with reputable business practices and a skilled installer may require more effort. According to the Better Business Bureau, the volume of complaints about home improvements, including window replacement, is second only to car repairs.

Next: Steps to take to avoid rip-offs >>