Double Window One Blind Or Two . 90” ÷ 3 = 30”. Each window blind operates independently of the other with it's own set of lift and tilt controls. Focus on window treatments roller and Roman blinds Real Homes from www.realhomesmagazine.co.uk One layer closer to the room and one layer closer to the window. The mechanism behind the blinds. Speak with a member of the flush fitment team on 0484 561 107, and we would be happy to further discuss day and night blinds with you.