Hehe, I wouldn’t even really want it. Was just needling the people who want their nice big houses without thinking about the isolating car culture it creates.
You wouldn't want it even if you could do it; it would be permanently overshadowed unless it was actually in Central Park or somewhere.
...or on top of an existing building.
That already exists as penthouse. I was thinking if you would get permission to build a farmhouse with lawn around it in the middle of Manhattan if you could afford the land.