With all of the bad weather going around these days, it's always a good idea to have a backup plan ready for when Mother Nature decides to throw a curveball (or, perhaps a rock through your window). With windows being the one weak point to your home, having a good understanding of your options when it comes to deflecting whatever Mother Nature throws at you. Specifically in this case, whether you should put storm windows up, or replace your windows all together.
Storm windows are additions to your house that are installed over your windows prior to a spell of bad weather. These windows protect your existing windows and will help to stop anything from breaking through. They can be installed by yourself if you are handy, and while they do need some maintenance every year, they work well to ensure that your windows will not be damaged. They are however, short term investments. You will have to change out your storm windows every three years, or risk them not being effective. Also, they tend to let less light in than your natural windows, aren't terribly energy efficient, and aren't as attractive as natural windows.
Replacement windows are exactly what they sound like. These are full replacements to your windows in order to have a better window in place that could withstand whatever a storm could throw at it. This is certainly more expensive than storm windows at the outset; however they will last much longer than your storm windows. They also have the added benefits of being the most up to date when it comes to energy efficiency and insulation. One of the main problems with this however, is that it will change the look of your home. While this may not be a problem for newer builds, older homes with historic charm may not be suited to newly engineered windows. This also has to be done by an expert so that the windows and their insulation are up to building code.
The choice really is yours on which way you choose to go, as both will work well against potential stormy issues. The main differences are in cost, aesthetics, and longevity, as well as personal preference of course. The other consideration that may come into effect is when the windows had been replaced last. If the windows have been replaced in the last 10 years or so, there may be no reason to go about any changes. However, if your windows haven't been replaced in over 30 years, you might want to consider full replacements.