Click image to see inside 8 multi-million dollar foreclosures.

NEW YORK (CNNMoney) -- Five years after the housing bubble burst, America's wealthiest families are now losing their homes to foreclosure at a faster rate than the rest of the country -- and many of them are doing so voluntarily.

Over 36,000 homes valued at $1 million or more were foreclosed on -- or at least served with a notice of default -- in 2011, according to data compiled by RealtyTrac, which tracks foreclosures. While that's less than 2% of all foreclosures nationwide, it represents a much bigger share of foreclosure activity than in previous years.

"These properties are accounting for a bigger piece of the foreclosure pie," said Daren Blomquist, vice president of RealtyTrac.

Out of all foreclosure activity, the share of foreclosures on properties valued at $1 million or more has risen by 115% since 2007 while the share of multi-million dollar foreclosures -- or homes valued at more than $2 million -- jumped by 273%. Meanwhile, the share of foreclosures on mid-range properties valued between $500,000 and $1 million fell by 21%.

Until recently, many homeowners at the high end of the housing market were able to postpone the foreclosure process, Blomquist explained. With other assets and alternatives, "they had more financial means to hold out against default."

In addition, lenders are typically more amenable to working with homeowners that have other resources, said Ron Shuffield, president of Esslinger-Wooten-Maxwell, a real-estate firm in Miami where homes priced over $1 million represented 9% of all foreclosures last year.

But with a recovery in the housing market still years away, foreclosure has turned out to be a worthwhile option after all. Saddled with bloated mortgages after a long run up in property values, many high-end homeowners have chosen to pursue a "strategic default." Even though they can afford the monthly mortgage payments, they still decide to walk away from their home because they owe more on the property than it is worth.

"In the lower-priced houses you'll see more people defaulting because they can't afford the payments and it's a choice between feeding their family and paying the mortgage on a home that's under water," said Stuart Vener, a national real estate and mortgage expert with the Florida-based Wilshire Holding Group.

"In million-dollar homes, you're looking at people who can afford it, but they have to make a business decision: Does it make sense to make payments on a mortgage when the home is worth less than they owe?" he said. In many cases, it often makes more financial sense to walk away.

At least they can take their time packing up all of their belongings. On average, it takes about 348 days for a foreclosure to be completed, Blomquist said. "They may get almost a year of free housing out of the deal."

But don't expect a few depressed mansions to bring down the neighborhood. A single foreclosure in an otherwise wealthy area is unlikely to impact surrounding values, Blomquist said.

"You're not going to see the weeds growing," Vener added. But there will be an opportunity for buyers to snatch up these impressive houses at bargain basement prices, he said, which could provide a much-needed boost to sales overall. "In a good way, this is going to drive turnover," he said.