The world's first billion-dollar home, commissioned for a petrochemical tycoon (surprise!) from India, will be a 27-story skyscraper in downtown Mumbai. Forbes mentions that hanging hydroponic gardens that "lower the energy footprint" of the house by absorbing heat and sunlight will dot the exterior of the first six floors. All of which, incidentally, are devoted to parking.

There's a slideshow here and an article here.

Via Archinect.