Single-Hung Windows, also known as Single-Sash Windows, are the types of windows that are designed with one movable sash, while the other sash is fixed. Generally, the lower sash of Single-Hung Windows is operable while the upper sash is fixed and not operable. The advantages of Single-Hung Windows include them using less material and thus becoming more cost-effective than double-hung windows, but their disadvantage is that they provide limited ventilation since only one sash is operable. Single-Hung Windows are a type of vertical window and are suitable for a variety of spaces and buildings.

Single-sash window designs have been in use since the 17th century, when they consisted of a wooden frame and a single pane of glass. The design evolved in the 18th century with the introduction of multi-pane windows, which used individual panes of glass separated by wooden muntins. The single-sash design remained popular throughout the 19th century with the advent of the Industrial Revolution and the mass production of windows. In the 20th century, new materials such as aluminum and vinyl were introduced, leading to further evolution of the single-sash design. Today, single-hung windows with a single sash continue to be a popular choice due to their affordability, durability, and energy efficiency.

Single-hung windows, with one stationary and one moving sash, are blending tradition with innovation. Today's designs offer wider panes for more natural light and enhanced views. Materials are evolving to be more eco-friendly, and energy-efficient glass options are reducing heating and cooling costs. Features like easy-clean tilting or built-in screens are elevating convenience. As urban spaces grow and the desire for efficient, user-friendly designs increases, single-hung windows will continue to adapt, ensuring both aesthetics and practicality.