A sleeping room in a green house or Wallpini is possible and perhaps very agreeable to live in.
Bill Mollison has suggested mentioned of this idea before, and the way that he suggested doing it was to split the
greenhouse in half: one half with the plants and animals facing the sun and the sleeping room half facing away from the sun. Essentially, you're just putting a wall and a door inside the
greenhouse to separate the two halves. If you add a few
chickens or small animals and a few holes inside the wall, the greenhouse can self-regulate its temperature. Say, you put one hole just big
enough for one small animal to pass through the wall. When the temperature is too high in the side facing the sun, the small animals will move into the other room one at a time to regulate the temperature. The animals produce heat and can warm up the greenhouse very nicely during the night. You will also find that there will be a turnover of the air mass in the greenhouse at night. Just be sure to add a hole or two near the top of the wall so the air can circulate properly.
The only things I might be concerned about are humidity and possibly radon.