We are building a house and I want to apply polyiso foam insulation board to the exterior. There is a floor to ceiling bay area off the kitchen that will have two narrow windows (RO 18″ x 60″) with a fixed pane in the middle (RO 48″ x 60″). There is not much room on either side of the small windows or between the large fixed pane and the smaller windows. I am in zone 5 and can use 1-1/2″ or 2″. I also have an opportunity to buy some 3″ polyiso 4 x 8 sheets reasonably priced. The issue is how to integrate the foam board with the windows. The windows would almost certainly have to be outties if I used the 3″ foam board. Has anyone successfully done this? Do you have any pictures I can see. Thanks for anyone’s assistance.