A single hung window is a tall window with two separate frames where only the bottom window actually opens. We install aluminum single hung windows that slide out when opened and have a vertical sash to lock them closed.
The aluminum single hung window is a popular impact window style because the aluminum frames are strong and won’t warp in the Florida heat and humidity. There are often used in home renovation.
They are less expensive than other windows and with fewer moving parts, often more durable. Like any impact window, they are missile-tested against hurricane winds and debris.