This Week in WTF: Cave Dwellers On Carroll Street?

Every day I walk down Carroll Street and every day for like TWO AND A HALF YEARS, I've wondered why there is a dirt-filled dumpster still parked outside somebody's fancy brownstone.

Well, now I know. I have it on good authority that a crazy rich dude (isn't it always) is digging a man cave to fucking CHINA in his basement. And yes, they really have been at it for over two years now. 

What I don't get is... isn't four stories enough? Or, if you can afford to buy or build anywhere on the four corners of this earth, why spend two years piling dirt into a dumpster? Why not buy two and have a double-wide? Or buy yourself a mansion somewhere (ELSE)?

What gives?