Replacing the windows in a home or business is one of the most common remodeling jobs an owner will have done. It can also be one of the most expensive. The owner of a typical two-story home can expect to replace between 15 and 20 windows total. Each window will usually cost between $500 and $700 installed. (Please note that this price is an estimate : prices will vary depending on region, manufacturer, type of window installed, and type of window being replaced). That puts the average total cost of replacing windows for a two-story home at more than $10,000 in most cases. However, if the replacement windows installed are upgraded (such as with low-e glass, triple-pane windows, and argon gas) for appearance and energy efficiency, the total can easily approach $20,000.