Yes, casement windows can be double glazed. Double glazing is a common feature in modern casement windows and is used to improve energy efficiency, reduce noise, and enhance security. Casement windows can be double glazed by replacing the existing single-pane window with a double-glazed unit. Alternatively, new casement windows can be manufactured with double-glazed units from the outset. Double glazing can be combined with other features such as low-e coatings and insulated frames to further improve energy efficiency and performance.