I built a Cuppola with 2'x7' operating windows covered with Rigid Greenhouse plastic sheeting. I also closed in a Steam Chimney with the same plastic sheeting and the Steam just rolls up and out!! Couldn't have worked better. Two boat winches and some pulleys open and close them. Sorry no photo of finished Cuppola other than the end by the Chimney. See photos sugarshack9.jpg sugarshack8.jpg sugarshack7.jpg