Double the size of a mansion in length and possibly also bigger in width but has no upstairs area. A cellar could be added I suppose for extra food storage. Contains a bonfire in the middle (Rather than implementing the bonfire as a buildable item itself and you need a chimney or other opening on the roof of the house).
Feasting inside the banquet hall should give a slight bonus, lighting the bonfire increases this bonus and having some amount of other players around adds to the bonus even further.