His permanent address is in the chateau. He's not a homeless drifter. The law is there to prevent people living indefinitely in caravans on empty lots, on the roadside etc. unauthorized places, even if privately owned (courtyard of a chateau is an authorized place btw.) If he wants to make his camper his official home, then he needs to apply permits from the authorities (and SJ), but since he's officially living in the chateau, there's no need for the permit. No law prohibits keeping a camper fully operational in the courtyard and sleeping in it, just not as an official residence, like in trailer parks with their own mailboxes, garden gnomes and patio furniture.