Hej, I've just had the same bug, and tried Azzinoth's suggestion. Open the savegame, delele the fog and level file and reload the savegame. And indeed it did solve the problem, the house (and Aura) are how and where they are supposed to be. I don't know if this disables achievements, the game didn't give me any indication of it, and it seems unlikely I guess.
Thanks for the hint )