Thom, there's a very slight error on one of these walls. On the wall with the round window and one large opening, the white areas to be cut out are the sizes of the door and rectangular window FRAMES, rather than the sizes of just the door and window.
http://miniaturearchitect.blogspot.com/2015/07/gorre-engine-house-in-n-scale-part-ii.html
Thom, there's a very slight error on one of these walls. On the wall with the round window and one large opening, the white areas to be cut out are the sizes of the door and rectangular window FRAMES, rather than the sizes of just the door and window.