Double-hung windows, also referred to as double-sash windows, have two operable upper and lower sashes. The most commonly selected style is those with sashes that open vertically. However, there are double-hung window syles with sashes that open on hinges, both inwardly and outwardly. In addition to providing additional ventilation compared to single-hung windows, double-hung windows offer a level of safety for families with young children since the upper sash can be opened to provide ventilation while remaining out of reach.