Double-Hung replacement window is a window that has two top and bottom halves (sashes) sliding up and down. Some call this window also a vertical slider. This type of the window is the most dominant in the New England region of the USA including CT due to its colonial history, decorative colonial feel that homes with such windows have. Plus, this type of replacement window is considered by many be the easiest, and therefore the most functional, window to clean. All you one has to do is to tilt-in the both sashes toward the interior of the house. This type of window is also a popular choice in the Great Britain.