One of the reconstructed buildings is a barracks, the other is the commander's house. In the Commander's house, the commander had eight rooms to himself*; in the barracks, the legionaries slept eight to a room. Mr Monkey decided he'd rather be the commander.
Tyne and Wear Museums have a web page about Arbeia.
* and his wife and family and servants, of course
Copyright Rik Shepherd and Mr Monkey. This page last modified 29 October 2003