1. When comparing windows be sure to compare the performance differences. Believe it or not, most windows do a very good or excellent job at sealing out a fairly strong wind when the outside thermometer registers 70° F. However, only a handful do well at sealing out a high wind when the outside temperature drops to zero. So, do not look at the claims or guarantees for the basic weather conditions, look for the extremes. When it's so cold that it is below zero, weather stripping and other components can stiffen or shrink, and cause your windows not to perform as well. In other words, when you really truly need them to perform is when they are most likely not going to. So, what window type is best and how do you choose windows that will work under the conditions your home will face? Start by asking your local window manufacturers and suppliers what they recommend for your area. Chances are they will recommend one of their more expensive windows. So, rather than shell out the money to buy that window, find out what makes that window the best, and look for windows with similar features at less cost. For example, you might be paying a higher price for upgraded knobs on the window but the actual feature that effects performance is equivalent to a less expensive window choice. Don't be duped by the pressuring sales man, you should know that aluminum frames are durable, but windows with frames made of vinyl- or aluminum-clad wood can perform well, too. So, look at the contributing factors, and determine what is a convenience feature you are paying extra for, and what is going to effect performance.

2. Be specific to your home and area. Not all windows are going to be the same. For example, you are going to want a different window type for your bathroom that you are for your bay window. So look at the recommendations made by the experts. Choose the windows that are designed for your region's climate, and for the specific parts of the house you are windowing. This is going to do a lot for you. For example, if you live in southern regions cooling costs predominate, so you are going to want to look for double glazing and a low-E coating. There are a lot of windows available, but because of your region you will want to give first consideration to windows with a low solar-heat-gain coefficient. On the other hand, heating bills are of concern in northern regions. Thus, for window shoppers of that region, the priority should be given to well-insulated, double-glazed windows that are draft-free. A low-E coating isn't essential in places where summers aren't particularly hot. In central regions, both heating and cooling are concerns. As in southern regions, look for double glazing and a low-E coating. You'll also want high insulating performance and a solar-heat-gain coefficient of 0.55 or lower.
3. Think about your personal tastes. When choosing windows know what you like, and what your lifestyle facilitates. For example, buying windows with wood frames may be your preference, but they require more upkeep than windows with vinyl frames. So consider all aspects of the windows. Other features that will be influenced by your lifestyle include things like tilt, for example, some windows tilt inward allowing you to clean them more easily.