Dick Friedman has too many houses and not enough time.

The C.E.O. of the Boston-based real estate developer Carpenter & Co., Friedman owns homes in some of the most exclusive locales in the world: his primary residence near Harvard Square in Cambridge; an island getaway on Martha’s Vineyard; a townhouse in Aspen; and a pirate’s-watch-turned-estate on Tortola, in the British Virgin Islands.

The homes are too special—the Tortola property, Frenchmans Lookout, has cathedral-ceilinged bedrooms and 360-degree ocean views, and the Martha’s Vineyard house hosted President Bill Clinton—to leave them occupied by only bored staffs for most of the year. Friedman’s solution: Rent out the houses in Aspen and Tortola for the 15 and 25 to 30 weeks of the year, respectively, that he’s not there.

As a builder and hotel proprietor—he owns Boston’s Charles and Liberty hotels—Friedman may have special insights into what his paying guests might want, but he’s hardly alone among C.E.O.’s in putting his personal playgrounds up for rent. Pony up enough money—the weekly rate for such properties starts around $20,000—and you can sleep in the room with wraparound views that for 20 years was Richard Branson’s favorite on Necker Island (he recently built another house for his family’s exclusive use), just a short helicopter hop from Friedman’s place on Tortola. Or, if you’re more into Bahamian style, L.V.M.H. C.E.O. Bernard Arnault’s Indigo Island takes paying guests too.

According to Farhad Vladi, whose Vladi Private Islands—based in Hamburg, Germany, and Halifax, Nova Scotia—arranges rentals and sales of islands and estates, the options are more plentiful than you might think, and so are the prospective renters. “The very rich don’t always want to buy,” he says. But the natural question for both guests and owners is: If you’ve got that kind of money, then…why rent?   

For the renter, it makes a lot of sense. Take Bill Gates, a client of Vladi’s who has stayed at Fregate, a private island in the Seychelles that offers all the luxury touches—hilltop, Balinese-inspired villas with hot tubs overlooking the Indian Ocean—but is so secluded that the only other visitors are the nesting sea turtles that venture onto the seven powdery beaches. On a private island, “there’s more security,” Vladi explains. You don’t have to deal with other guests in the hotel, and it’s less accessible to paparazzi. And it’s easier to rent than to own. “Guests can rent once and go away, and visit a different place the next time,” he says. “And they don’t have to worry about the infrastructure,” which can range from maintaining a property to dealing with staff concerns.

For the owner, making a profit isn’t a priority—if you can afford to buy a private island or a fifth home, you’re probably not too worried about how much it costs to keep the lawn mowed. That said, rental fees do offset taxes, maintenance costs, and staff salaries. There are also tax benefits: Renting out a property allows owners to write off expenses as part of the cost of doing business.  

Then there are the psychological benefits. By offering your private island for rent, you make it a little more public. In other words, you get to show off. “In some cases, the owners want to have a few others who are really discerning appreciate what they have—their furnishings, their art—to enjoy it as they do,” explains John Steinle, president of Sanctuare, a company that arranges the rental of a small group of elite properties around the world such as Motu Tane, a private island near Bora Bora owned by cosmetics tycoon François Nars. “Even more important, though, it keeps the staff sharp and motivated. And it’s better for the house to be lived in than to sit vacant.”

In some cases, the owner’s identity is well known; it’s no secret that Branson owns Necker, a forerunner of the personal-rental trend, which he purchased in 1976. But others like to keep their identities hidden—along with their most personal belongings, which are gathered and locked away by the estate managers. You wouldn’t know that Microsoft co-founder Paul Allen owns Teton Ridge Ranch in eastern Idaho unless a fellow guest drops his name. The managers speak of him only as “the owner,” though the three state-of-the-art computers shared by five guest rooms are a tip-off to the high-tech connection.

Living in someone else’s environment means adopting—at least temporarily—their taste level and decorating style. Most of the time, given that these homeowners live pampered lives and employ renowned designers and architects, that’s not a problem. In some cases, though, there are exceptions. The managers of one private island in the British Virgin Islands had an unusual incentive to lock away an owner’s personal touches when paying guests arrived: The kitschy ceramic frogs and other animals were deemed insufficiently tasteful for a property priced at $10,000 a day. When the owner returned, so did the knickknacks.

To maintain a certain level of taste, the executives of the Mustique Co., which developed and manages the island, keep a sharp eye on the 100 villas there. Many are owned by luminaries such as Mick Jagger and Tommy Hilfiger, and rented out by the company when they’re not in residence.  

“Owners of some of the older villas have to upgrade them,” says Linda Bruno, director of marketing for the Mustique Co. “When people are spending at least $20,000 a week, they’re not going to be forgiving if the furniture is shabby.” Conversely, though, guests can benefit from an owner’s particular preferences. L’Ansecoy, the villa owned by Maguy Le Coze, proprietor of New York City’s Le Bernardin, “gets a lot of repeat business,” says Bruno. Decor and view are two reasons. Another is the chef, who trained at the restaurant.

Repeat guests can get attached to a specific house; occasionally they become possessive about it. As Bruno observes, one couple who rents Les Jolies Eaux, the former villa of the late Princess Margaret, several times a year happened to meet the current owners at an event in New York City recently. Though the conversation was cordial, the blast of reality was unsettling. “They really felt it was their villa,” she says. “They got so attached.”

Then there’s another type of collision between owner and renter, which takes place when the owner would like to stay in his or her house but can’t because a renter has possession, a conflict even Branson has faced. Says Dick Friedman, “I try to hold certain weeks for myself. I have an eight-year-old, and I know when he’s on vacation from school.” And as an avid skier and former ski coach, Friedman takes the Aspen house off the market for most of the winter even though the demand to rent it is high. “Because,” he says, “if someone from Colorado calls and says we just got two feet of snow, I’m out of here!”