A sash window is a type of window that consists of one or more movable panels, known as sashes, which hold the glass. These sashes can slide vertically or horizontally, allowing for ventilation and easy cleaning. Sash windows are commonly found in older buildings and are often associated with the architectural styles of the 18th and 19th centuries. Typically made of wood, sash windows can be single or double-glazed, providing varying levels of insulation. They are often seen in historic homes and are valued for their aesthetic appeal and functionality. Many homeowners choose to restore or replicate Victorian or Georgian sash windows to maintain the character of their properties.