Check out this stage layout
for the original STAR TREK. There are two doors, one into the living/office area and another into the sleeping area. Depending on whose cabin this was dressed as, say Spock or Janice Rand, the living and sleeping area configuration were flipped from Kirk's.
Check out this screencap from "Journey to Babel":
"Journey To Babel"; Kirk's Cabin
by Clark "Kal-El" Kent
, on Flickr