Antilia
The house of Mukesh Ambani, chairman of Indian energy company Reliance Industries, is seen in Mumbai.

India's wealthiest man Mukesh Ambani's 27-story skyscraper home in Mumbai has topped the Forbes List of the most expensive billionaire homes in the world.

The 400,000-square-foot house is named Antilia after a mythical island in the Atlantic.

Ambani, chairman of Reliance Industries, reportedly spent between $1bn (€728m, £593m) and $2bn for the construction of the house.

That equals the construction costs for 7 World Trade Center, the 52-story tower that stands just north of Ground Zero in Manhattan with 1.7 million square feet of office space.

"The title of the most outrageously expensive property in the world still belongs to Mukesh Ambani's Antilia in Mumbai," Forbes said.

The 570-foot skyscraper includes six stories of underground parking, three helicopter pads, and reportedly requires a staff of 600 to keep it running.

Construction on the building started in 2008 and finished late in 2010.

Antilia
The house of Mukesh Ambani, chairman of Indian energy company Reliance Industries, is seen in Mumbai October 23, 2010. Ambani, his wife and three children have moved into the 27-story building, which is named Antilia, after a mythical island, local media reported.

The second in the Forbes list is Lily Safra's Villa Leopolda, in Villefranche-sur-mer, France. Spanning over 20 acres, the property is reportedly one of several waterside homes that King Leopold II of Belgium built for his many mistresses.

It was valued at €500m, when Russian billionaire Mikhail Prokhorov tried to buy it in 2008. Prokhorov eventually backed out of the deal, losing his €50m deposit.

The third-most expensive billionaire home is Ira Rennert's Fair Field in New York. The property, which has never traded hands, is valued at about $248.5m in its latest tentative tax assessment.

The property boasts of 29 bedrooms, three swimming pools and its own power plant on premises.

Recently sold at $237m, a penthouse at One Hyde Park, London is the fourth one on the list. The apartment was sold to an Eastern European, who is believed to be a billionaire.

Lakshmi Mittal's Kensington Palace Gardens in London is the fifth most expensive home in the world. Hedge fund billionaire Noam Gottesman sold the property for $22m in 2008.

The steel magnate is believed to own three homes on the high-security street known as 'Billionaires Row', including a neo-Georgian mansion near the Israeli embassy.

Forbes noted that property values are going up in the ultra-luxury market. Of the 20 most expensive homes in the world owned by Forbes billionaires, only six were priced at less than $100m.

"Although the market cooled off a bit in 2013, with no properties trading hands above the USD 100 million mark, 2014 has kicked off with a bang. London set a new record, and three homes have sold for more than $100 million so far this year in the US alone," Forbes said.