The Floating House

It amazes me how well done , how perfect the little house is. To me the person who built that one even calculated where the stream would go so he could have only one boat as shown in the movie.
I dont know if the gates to the pier actually close by themselves or it was just some effect for movie but I would like someone to post some information on the house and the hole engineering used in its construction.
How does it stays floating ?
How is it able to spin around (wich was incredibly beautiful to see through the eyes of the camera) , and even move around as we see in the scene right before the old monk is about to suicide inside his boat.
How does the pond work ? Is it connected to the water ? How can water run constantly in that pond ?
What is that kind of building called and where can I see more of those ?
Is there some sort of anchor to hold it in the center of the lake so it wouldnt float to the shore ?
What kind of wood is used that can prevent extreme degradation from freezing and defrosting all year around ?
If anyone could answer just one of two of this questions I would be grateful.