BOSTON -- When Michael Belanger didn't get any takers for his $2.7 million Cape Cod beach house, he decided to try a different strategy.

"We're offering essentially 1/12th fractional ownership, an undivided tenant in common ownership, to four families," Belanger said.

For approximately $100,000, buyers get three summer weeks in the unique property located on the beach at 100 Cross St., in Cotuit. It includes a one bedroom plus loft beach house that dates back to the 1890s, as well as a salt water pond with gazebo and direct access to nearly 200 feet of private beach.

But under this fractional agreement the five families would share the outside property year round even when one family is in residence. They would all share the decks, the outdoor grills, boats and parts of the beach.

"This is a cooperative nature," said Belanger. "It's kind of like a residential club. It's a larger family, essentially."

Sharing boats is also a popular way to keep summer fun more affordable. Family and friends often work out schedules and responsibilities. It, too, requires flexibility.

"That's the one drawback," said to Douglyss Giuliana, president of SailTime Boston. "You can't wake up in the morning and say, 'I want to go sailing today.'"

SailTime, a company run out of Boston's Fan Pier, offers a more professional arrangement with computerized scheduling and maintenance-free boating.

"Fractional programs are ideal for someone who wants access to a high-quality item but can't justify financially owning it themselves given the limited amount of use it would get," said Giuliana.

Experts said fractional ownership can be a good option if you know the answers to three key questions.

"I think the real concern is making sure you've got the language on what's covered. What are you paying for? And what are you getting? And lastly, what do I do when I want to get out?" said Kathleen O'Donnell, a Milton real estate attorney.

Just like full ownership, you will likely need to find a buyer for your share if you no longer want it.

Overall, O'Donnell said, "It's not a bad idea. People have been doing it for centuries. But who are you doing it with?"