Hello Geez,
I just uploaded a screenshot of the area on the map with building circled in red. The blue highlights are the areas where I've noticed no collision along the outside building edge walls and ledges. The stairs on the NW side of the building also allow you to hide through them because there is no collision. Let me know if the screenshot didn't upload for you.
BTW I made this bug report private because I didn't want other players to see you can exploit/hide in this building. Hope that is the right protocol.
Regards,
alhaknslash