In reply to goatee:
If you find a suitable bivi above a hut (out of sight of it that is, doesn't have to be far away, just around the corner or on the next morain), it is very unlikely anyone will bother you. There are plenty of bivi rings of stone, also people quite often put tents up in them. It is highly unlikely that the hut people will rush out in the day to try to persecute you, though of course people setting out on routes will see your tent, but they are very unlikely to interfere with your setup.
Post edited at 21:22