Saying Phoenix academy was just a large academy was an understatement, Phoenix academy was the largest academy in the world and even the second-largest academy didn't come close to it in terms of land mass.
The academy contained a large stadium, academic blocks, dormitory areas, teachers' quarters, a military barrack, and even a huge museum and on top of all these buildings, it still had more than enough space to accommodate more buildings.
This was the reason why it was possible to accommodate all the students inside the academy, the academy was hosted by Eukerion academy last year and the academy only had enough space to contain only one guest academy the other academies had to stay at the hotels close to the academy.
Just behind the barrack in the academy was a three-story apartment building that was meant to accommodate all the staff from the guest academies.
The rooms were apparently not enough for everybody so some of them had to share the rooms.