A replacement window is a window that is installed in an existing window opening as a replacement for the existing window. Old weather-worn windows deteriorate and become loose and drafty. They need to be replaced not only to improve the home’s appearance, but also to take advantage of modern, energy-efficient windows that provide an overall home environment improvement at a low recurring cost for heating and cooling. The production of the windows we use comes with argon gas to give you the highest energy cost efficiency in your home.