Antilia is a private home in South Mumbai, India. It is owned by Mukesh Ambani, chairman of Reliance Industries, and has a staff of 600 to maintain the residence 24 hours a day.
As of November 2014, it is deemed to be the world’s most expensive residential property, after Buckingham Palace, which is designated as a crown property. It is thus the world’s most expensive private residential property, valued over USD1 billion. Its controversial design and ostentatious use by a single family has made it infamous across the world, with severe criticism in the architectural press and mockery in popular media.
Antilia was built in consultation with US architecture firms Perkins and Will & Hirsch Bedner Associates, with the Australian-based construction company Leighton Holdings initially taking charge of its construction. The home has 27 floors with extra-high ceilings.
The X-Seed 4000 is a one of the most special building ever fully planned and designed on this planet. The X-Seed would have had roof 4000 metres above the ground and would be built in Japan. The idea was initially created and developed by Peter Neville. It would have a 6000 metre base which would be underwater and 800-floor capacity could accommodate 500,000 to 1,000,000 inhabitants. This structure would be composed of over 3,000,000 tons of pure steel.
Unlike conventional skyscrapers, to remain habitable the X-Seed 4000 would have to increase the pressure according to how high it goes and should have separate generators at every 100 floors. The X-Seed would have taken at least 20 years to complete and would cost about USD700 billion to USD1.2 trillion.