Although the media have focused on the large numbers of millennials who have struggled to get a toehold on their financial independence during the economic downturn, a smaller segment has been making news for their phenomenal wealth. Facebook founder Mark Zuckerberg is perhaps the most famous example, but millions of other millennials have amassed sizeable fortunes while still in their twenties.

And what are they doing with all that money? Among other things, buying luxury homes.

Millennials make up nearly a quarter of all U.S. millionaires, or about 5 million individuals, according to a survey conducted by the Shullman Research Center. Compared to their baby boomer and Gen X counterparts, affluent millennials are more likely to make luxury purchases and to spend more for some items, such as luxury vacations and properties.

A new report from Coldwell Banker and the Luxury Institute finds that among wealthy consumers (those with a net worth of $5 million or more), those under age 35 own 2.87 properties compared with 2.04 for all pentamillionaires and 1.44 for those age 65 and older.

In addition, the average price paid for the most recent luxury home purchase by young wealthy buyers was $7.8 million, compared to $2.7 million for those ages 45 to 64 and $1 million for those age 65 and older. Moreover, 80 percent paid cash in full for that purchase.

Even better news for the luxury real estate market is that 73 percent of the under-35 pentamillionaires surveyed for the Coldwell Banker/Luxury Institute study say they plan to purchase residential real estate for their personal use in the next 12 months, compared to about half of those in other age categories. Another 8 percent plan to purchase property for investment purposes.

Young wealthy buyers have decided preferences for what they want in their next home. At the forefront of today's highly mobile workforce, this group has greater flexibility in where they choose to live. Three-quarters of those surveyed indicated that lifestyle considerations were more important than location in deciding where to purchase a home.

They also favor new home construction. Again, nearly three-quarters said that finding a suitable home that was "fully built, equipped, ready to move into, and subsequently easy to live in and maintain" was more important to them than it was three years ago.

Young, wealthy buyers also are seeking greener homes. About one-fourth say they are planning a purchase because they want to build or buy a green, eco-friendly home; and nearly one-third responded that having a green or LEED-certified home is more important to them than it was three years ago.

Among the amenities that ranked highest for young wealthy buyers were a safe room (37 percent), home theater (36 percent), pool (34 percent) and outdoor kitchen (33 percent). Surprisingly, this group was less likely than that of ages 36 to 44 to state that a fully automated and wired home environment was more important to them than it was three years ago, but that may be because they simply take it as a basic necessity of any home they would purchase.

For interior designers and remodelers looking to attract these buyers as prospective clients, the report also contains some useful marketing insights. As might be expected, more than half of the young wealthy respondents reported that social media and online reviews affect their choice of properties and real estate agents. Still significant, but of less importance, was a referral from a friend or family member.

When asked about the most important characteristics of the real estate agent they most recently worked with, they gave the highest rating to knowledge of the process, experience and credentials — attributes that interior design professionals and contractors can capitalize on in their own promotional materials.