Need to replace a window? Maybe the window is cracked, broken, or it is stuck. No worries, a window contractor is there to help you with this undertaking. One of the main reasons why people should be replacing their windows is their lack of energy efficiency. Old windows allow energy to easily escape, causing your house to cool considerably during the colder months. During the hotter months, these same windows also do not keep out the heat, so you end up paying more money on your air conditioning bill. Not only that, but old windows certainly do let almost every single sound in!