I wonder if he began by writing “They live together under one roof” and then decided it would sound more mature to write “They live together in one household”…and didn’t replace enough of the words. Student writing often contains sentences that seem like the bad result of a collision between two reasonable sentences: two impaired parts of a thought badly stitched together to make not quite a natural new reasonable statement. Frankenstein’s-monster sentences, perhaps one might call them.
Actually, since the sentence comes from an essay on the “reality” show The Jersey Shore and was describing the (unrelated) participants of the show, probably “under one roof” would have been more accurate than “in one household.” The rest of the essay didn’t describe people collaborating as a family unit, which is what “household” implies to me—more like people hanging around (etc.!) together in rather irresponsible ways.
Not much more needs to be said about how the sentence itself occurred—unless it actually spilled uninterrupted from his fingers this exact way, without any second-guessing or efforts to revise, in which case what can be said?
But of course the reader’s mind’s eye won’t leave the sentence that quickly. No fan of the stereotype Jersey Shore evidently exists to perpetuate, my mind’s eye refuses to define “They” as the television show defines them; instead, for the sake of this sentence, I imagine a family of gnomes, or elves, or perhaps counterculture holdouts. There they are, surreptitiously dwelling in the sub-basement, or a cave beneath the basement, or even in the dark corners of the basement, of a household of people who go blithely about their lives ignorant of the creatures who share their domicile. A lot of chuckling goes on down there, I assume. I think of them as a fairly jolly bunch because they have each other, and because in a harsh economy they’re living not so much off the grid as under the grid. I wonder if, like Ellison’s Invisible Man, they’re tapping the electric lines (upstairs the harried bill-payer remarks, “The previous owners REALLY misled us about utility costs!”). Do they creep out at night to do their shopping, or is their entrance sufficiently screened from view that they can come and go as they please? Do the householders hear them singing, or talking, or moving about, and think there are mice? And do the gnomes (or whatever) eavesdrop on the householders and comment to one another on the relationships and activities above? [I’m not sure if “eavesdrop” is an appropriate term for listening from below, but I can’t think of an equivalent.]
One of the books I had as a child contained an illustration of a family of tiny people living in perhaps a hollow tree, or the space under its roots. I remember that the illustration took the shape of the circle of light cast by their candle, and they all had pink cheeks and nice faces. I’d pick them to live under my household, if they’re looking for new digs.