Oh, I don't know. My hens must be goof-balls because they're up on the roost all the darn time. It runs right in front of the eastern window and they can watch the sun rise. My other window is on the south side and they can see out of it from the roost. Both are double hung, double pane, one large and one medium sized.
I think if you use good design, there's no reason you couldn't put the roosts over the nesting box. Make sure you make a nice, wide poop board and then the nest box can go under that. Chickens produce a lot of poo at night when they sleep, so the majority of the poo in the coop is directly under the roost.
It's also very very cold here, but I am sooooo glad to have the windows, especially in the winter when the girls spend 99% of their time indoors.
ETA: Chickens like it dark and private in their nestboxes, so if it's going to be under the window you might want to make sure it's enclosed. Personally, I'd rather have the nestbox under the window vs. opposite it where it would be constantly bright.