Storm windows offer alternative to full replacement
Storm windows are essentially the forerunner to today's double-pane, insulated windows. Older, single-glass windows were fine during the summer, when temperatures were warm and windows were often open for ventilation. In the winter months, however, those single-pane windows became a cold and drafty annoyance. So, since most people didn't want to open their windows all that often in the winter, they added storm windows to help minimize heat loss and keep their homes warmer.
The older style of storm window was simply a fixed pane of glass in a wooden frame. Hooks and clips held the frame in place during the winter, and they were taken down again when the weather warmed up.
There are several problems with this type of fixed storm window, however. They need to be put up and taken down each year, they need to be stored somewhere, they require periodic maintenance, they decrease available light in the house, they prevent ventilation, and most importantly, they can present a life-threatening impediment to escaping from the house in the event of an emergency, such as a fire. In fact, in many jurisdictions storms windows are now prohibited in sleeping rooms unless they have a simple means for opening them to allow for emergency egress.
In order to meet building codes and provide ventilation, today's storm windows are custom-made in configurations that match the window they are going to be covering. Wood is seldom used any more, having been replaced with more economical aluminum or vinyl. Also, in order to form a more draft-resistant seal and eliminate the hassles of removal and storage, most of today's storm windows are permanently fixed in place.
Storm windows are available in both interior and exterior styles, and both have their advantages. Exterior storm windows, which are more common, do not rob any interior window sill space and they cover older, less attractive windows to provide a fresh look to the outside of your house. Interior storm windows, on the other hand, may be easier to install in some homes, and they provide a good alternative for people who don't like the appearance of exterior storm windows.
While storm windows offer some energy and budgetary advantages, they also come with some disadvantages that should be considered before making a decision. Opening a window now requires that you open two sashes instead of one, and you have also doubled the amount of glass you have to clean. In terms of resale value, storm windows are typically considered better than single-pane windows, but not as good as the more common double-pane windows.
Today, storm windows are most commonly built and installed by a professional, licensed and bonded glass company. They will make a site visit to your home, examine the style, condition and configuration of your existing windows, and help you determine what type of storm window will look and work best for your home. They will also provide you with a complete written estimate of the costs, along with ordering and installation time frames and any warranty information.
Be sure to ask the glass company to show you samples of the different types of storm windows, and if at all possible ask if you can visit a couple of homes they have done installations on -- it's important that you have a chance to see exactly what the storm windows look like, and also to talk to another homeowner about there experience with the installers.
A TEMPORARY ALTERNATIVE
If you're thinking about storm or replacement windows next summer but need to stretch things through one more winter, temporary storm windows may provide a workable alternative. Temporary storm windows, available through many home centers, come in a couple of different styles, but they are essentially just shrink wrap plastic that covers the window to stop air leaks.
Temporary storm windows are designed for only one season, and they prevent ventilation through the window and also block some of the light. They're pretty effective at blocking drafts however, and since they are easily ripped off they are allowed by most building codes in egress situations.
Before undertaking any storm window installation -- permanent or temporary -- be sure and check with your local building department to make sure what you're doing is both safe and legal.