Lynn Tran and Richard Hazen built a Florida beachfront treehouse that would be the envy of any child. It's got two levels, hammocks and windows looking out on the Gulf of Mexico.

But the hangout has cost the couple a handsome sum: about $30,000 to construct and probably five times that in legal fees as they've fought local authorities over it, Tran said. Now, they're at their last stop, the U.S. Supreme Court. Unless the high court intervenes, the treehouse must be torn down.

The justices had their first opportunity to consider taking the case at a closed-door conference Friday, and a decision on whether they will weigh in could come this week.

The couple's lawyer, David Levin, acknowledges the case is unlikely to be accepted by the justices, who only hear argument in about 80 of the thousands of cases they're asked to take each year. But he argues that his clients' rights were violated when a Florida court “rubber-stamped” a ruling proposed by the city of Holmes Beach without any evidence of independent consideration.

Tran and Hazen haven't been willing to give up on the structure she calls their “getaway.”

“Part of me still believes there's got to be justice out there and we didn't do anything wrong,” Tran said in a telephone interview.

Tran and her husband run a rental property called Angelinos Sea Lodge on Anna Maria Island on Florida's west coast. They have a house on their property and four rental units.

Before they began constructing the treehouse around an Australian Pine on their property in 2011, Hazen asked the city whether they needed a permit. The answer: No.

So, with some help from the internet, Tran dreamed up the structure, which took six months to build.

Soon, however, the city got an anonymous complaint about the treehouse. After an investigation, the city found the couple did actually need to go through the permitting process. And it turns out the treehouse was in an area where building is prohibited because of a city setback. The couple hoped to get around that by having local voters weigh in, but courts told them no.

Holmes Beach Mayor Bob Johnson noted in a telephone interview that courts have sided with the city and he called the continued legal wrangling “quite honestly a waste of time.”

“For some reason these people have this fixation on it,” he said.

Tran says she never expected such a drawn-out fight and that in hindsight the couple could have taken the money they've spent on the treehouse, gone somewhere else and built an actual house.

It's still costing the couple. They're accumulating a $50 a day fine for not taking down the treehouse, a fine that's now tens of thousands of dollars.

Tran says she's afraid to think about it. Until the high court acts, she's enjoying the treehouse on sunny days, meditating there or napping in a hammock. The couple doesn't have any children of their own enjoying the treehouse and renters aren't allowed up for liability reasons, but Tran says guests and beachgoers often admire the structure.

“It's kind of fun to have around,” she said.

If the treehouse ultimately has to go, there's a lurking irony for the couple. To take down the structure, they'll need the one thing they didn't have before they began putting it up: a city permit.

Jessica Gresko reports for the Associated Press.