You’re unlikely to recover the cost of replacement windows from the resulting energy savings unless your current windows are extremely inefficient. But there are other good reasons to replace old windows: If they are ugly, deteriorating, or drafty; if they are hard to wash; or if you want to minimize your home’s energy use and the environmental impact. You might also want to install a window where there was no window before.

When shopping, keep in mind that the kind of windows you buy will affect your home’s appearance, the amount of light admitted, your comfort, energy savings, and how long the windows last.

Check salespeople’s claims about energy savings with comparisons we make in our article on energy efficiency and consulting For information on durability, check the results of Consumer Reports’ tests. Also compare warranties.

There are, unfortunately, a lot of unhappy window customers. Some companies were rated “inferior” overall by 25 percent or more of their surveyed customers. But we also found some very highly rated installers.

Obtain several price quotes. Our undercover shoppers found big price differences. For example, for one window replacement job our shoppers received quotes from area companies that ranged from $1,750 to $4,761.