Who is Herman Barnes from Factotum and what is their importance?

Herman Barnes is the maintenance superintendent at the Times Building in Los Angeles, Barnes assigns Henry to polish brass, only to find him in a bar across the street having a beer. He gives Henry a second chance, replacing burnt out fluorescent tubes, and accepts Henry's fear of heights as an excuse for doing nothing. Finally, he puts Henry under Jacob Christensen as a night janitor. When the two men discover Henry asleep in the ladies room, he is fired.