Ok, then you move on to the pumphouse. I don't know the square footage, but I believe the building would cost about $500,000 in Northern California money.
As you come to the door, you notice that it has its own address.
You enter the "Fish Geek Playroom," where one would obviously spend a great deal of time. There is also a well-stocked refrigerator at the end of the bar with libations for humans and treats for koi.
Then you see two glass door leading to the filter room. A trickle tower sits on the landing between the doors. The door behind the tower opens to the stairs to the main filtration.