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...the median American house size is slightly more than 2,000 square feet. Compare that with the domicile of the world's richest man...Bill Gates' house is more than 30 times the average size. The NAHB says that most houses have three bedrooms, one fireplace and are sided with vinyl or aluminum. Some billionaires' homes have more than a dozen bedrooms, and the only vinyl is in the rare-record collection housed in the custom-built listening room.

Yet as extravagant as some of their mansions may seem, the homes of
the super-rich are not out of proportion to their wealth. In fact,
comparatively, they can seem downright modest. According to the National Association of Realtors, about one-fifth of a household's wealth is composed of home equity. Let's say that held true for Warren Buffett: The mastermind behind holding company
Berkshire Hathaway is second on our list of the World's Richest People, with an estimated net worth of $44 billion. If he sank the average 20% into his home, the property would have to be worth...oh, approximately $8.8 billion--roughly the gross
domestic product of Iceland.

Instead, Buffet lives more like a millionaire than a billionaire. For
nearly 50 years, he's bedded down in the same Omaha house he bought
for $31,500. Although far from elaborate, it is still more than
adequate. In 2003, the local assessor pegged its value at nearly
$700,000. Buffett disagreed--he thought it was worth closer to
$500,000. Like Gates, though, most billionaires are willing to lavish millions
creating their own private Xanadus. Prince Alwaleed bin Talal Alsaud of Saudi Arabia has a 317-room palace in Riyadh, which reportedly cost $130 million to build. Totaling 400,000 square feet, it has a soccer field, eight elevators and more
than 500 television sets. Then again, he has $23.7 billion in riches,
including a longtime 3.9% stake in Citigroup. And why not? Even if you don't need the mortgage-interest deduction on your income taxes, there are practical reasons to own a mega-mansion, like...