Hopper windows are single-sash windows that open inward from the top (think of an upside-down awning window). They typically are used to allow a bit of sunlight and ventilation in rooms where you wouldn’t necessarily want people looking back in, like the laundry room, basement and bathroom. These windows improve home value by adding light to rooms that otherwise might be very dark. Hopper windows can be used as the exterior outlet for dryer vents when mulled to a small, insulated picture window or other window type.