Here is something I've never seen. Roof enclosed with a roof??

[Bobby Coomer]

I've walked thousands of houses and this was a first for me. The house has a 1 room second story addition on the back of the house (as well as a converted attic space, 2nd story room in the front of the house). There was a hole in the interior wall of the new addition, so obviously I took a look. What I saw can only be described as an addition where the new roof was added over the old roof creating a vacant space between the front and back second story rooms. Has anyone encountered this before? I would be inclined to think that this would not pass building code due to venting and issues with the structural integrity of the added weight, but does anyone have anymore insight? I have added some photos to better explain. Thanks for the info!