I was watching the episode "A night not to remember" the other day and noticed 2 things.

1. On the first attachment, we see the very edge of the set (bottom left)
2. On the second attachment, a strange wall can be seen outside of Jack's bedroom. Immediately after entering Jack's bedroom, Janet closes the door for no apparent reason. Could be to hide this?

I know we sometime see the kitchen being a tiny room but I always pictured Jack's bedroom being directly connected to the rest of the set.

So unfortunate actors don't participate in these forums to clear things up.

We find this show did this when we saw it with the kitchen. You would think the set would always have the furnished kitchen. However for whatever reason for us rookies, we dont know why directors needed their own space, own rooms to accomplish a scene.
I could be wrong but did not Jack's room change over the years. In the first few seasons, I don't remember a desk being in front of the door.
It seems once the actors when through a door, the scene was cut and then filmed in a furnished room.

It was an interesting show!!!!

I would think that the bedrooms and bathroom sets would all have to be separate sections, perhaps rolled into place as needed. The studio audience and cameras would not see the action filmed in Jacks room if the set was laid out as the apartment supposedly was. The view of the bedrooms would have been blocked by the bathroom (looking straight onto the set, anyway). I often wonder if the girls room is really too short to fit as the bathroom door seems to be too close to that door. But that could just be the camera perspective being off to reality.