For instance ... "in this house" ... ... often during the interviews the producers will seek for more specific statements when the contestant says something that could be construed as being vague. For instance, if Levi is talking about Brian, and he says ... "That guy is such a d---", the producer will often say, "What guy? Can you say it with his name?" That's why during the interviews in the episode the contestants will specify who they're talking about most of the time.

((It's also why they often sound so annoyed, because the producer probably made them say the same thing 2-5 times in a row because something wasn't quite right. Sometimes it'll be something as little as a car honking off screen in the middle of the speech. "Did you get that, Sound Guy? Oh, sorry, repeat that one more time." Very common in on the spot interviews (Called OTF's)))

I imagine 'in this house' might be caused by something similar, the contestant could say, "God, nobody can stand me here!" The producer might say, "Here, where?" Contestant, "In this house." Producer, "Could you re say it saying that?" And there it is. ((This is during the interviews specifically, producers rarely disrupt the real-time drama.))

I mean, I don't know for sure, I worked on Wife Swap and that wasn't the same type of reality show ...