We later find out that the doorway to the far end of the bathroom is the main stairway...so they must have a room down there somewhere.
When Cliff wakes up from hearing Sondra and Denise blasting their stereo and runs to their room to shut it off, he runs down the hallway to his left, past the bathroom door, to get to their room. In later episodes, however, Sondra and Denise's room is depicted as being right next door to Cliff and Clair's room on the right side, across the hall from Theo's room. What happened to the extra bedroom?
For his work in this episode, Jay Sandrich won an Emmy Award for Outstanding Directing in a Comedy Series.
Sondra and Denise are listening to AC/DC's High Voltage, their first album released in the U.S. The cover can be seen when Cliff picks up the album.