If you live in an older house or apartment, you might want to consider storm windows to increase your comfort and possibly lower your fuel bills during the winter. Storm windows fit right over your existing windows, and provide some extra insulation as well as preventing drafts.
Why Storm Windows Are a Good Option
In cold weather, single pane windows can lose ten times more heat than an equal sized area of wall; and in many homes, windows account for more than 25% of a home's heating and cooling bills. This said, a little help is nice. Undoubtedly, the best way to improve your home's energy efficiency is to install new modern energy efficient windows, but an economical option might be to install storm windows. Storm windows can be installed on the inside or the outside of existing windows and range from thin plastic sheets that last for one winter, to double and triple paned glass windows with special low emission coatings that are designed to last for years.
Interior vs. Exterior Storm Windows
While it is possible get storm windows that mount on the outside of existing windows, they are relatively expensive. So, if you can afford them, you can likely afford to pay for installing the modern energy efficient windows. However, interior storms are another alternative and they're well suited to apartments or even multiple level homes. They're convenient, easy to install and remove, don't need much maintenance (since they aren't directly exposed to the outside elements), and for the most part they're effective in stopping air infiltration.
Storm Window Materials
When it comes to interior storm windows you have lots of choices. Plastic storm windows are inexpensive, and relatively easy to install, but, they have the disadvantage of being easily damaged. While you can get plastics like Plexiglas that resist breaking, Plexiglas scratches easily and can yellow over time when exposed to sunlight. Glass windows provide the best visibility and long life, but glass is heavy and breakable.
Storm Window Frame Materials
Frames are much like regular window frames. Your choices are essentially wood, vinyl, or aluminum, and each has inherent advantages and disadvantages. Wood provides good insulation values, but it is heavy and requires maintenance over the years. Aluminum is light and long lasting, but it's a poor insulator and transmits cold. Vinyl has the advantages of being low maintenance, light in weight and can be easily color matched. However, prolonged exposure to sunlight can cause vinyl to lose color and it will develop cracks with age.
Storm Windows: Cost vs. Payback
Storm windows are a compromise. While they will provide some energy cost savings, the payback period is fairly long and depends on their original cost and the cost of the energy itself. However, even if they don't provide a quick economic return, the value of storm windows lies in the increase in home comfort you get from eliminating drafts and cold rooms in your house.
For further information for doors see the following article from HomeDoctor.net: Storm Doors.