Thank you for the kind comments! I wasn't sure it could be gamed either, but a lot of research and mucking around with concepts went into the final model.
To answer two questions:
The walls are textured card by a German model railway company called Vollmer. It's printed and embossed as well with the stone pattern, so saved me a huge amount of work. I just gave it a matt varnish spray and then added some streaks and stains.
The bunkbeds are made out of Warbases mdf bases. I just ordered a job lot of 20x30mm rectangles. The dimensions were really dictated by the size of the barracks rooms, but they do look about right. I assembled them all in one evening using a hot glue gun. Blankets were added from resin baggage castings, foil, green stuff etc. the pillows are single sandbags from the Renedra sprue.