Michael McElroy for The New York Times  The interior of Thomas Kramer's house on Star Island in Florida.  MIAMI BEACH — In this decadent, hard-partying playground, Kirsty Bertarelli’s 40th birthday celebration rivaled the best of them. More than 200 guests flew in from Europe. A caravan of limousines ferried them to the site, a flashy waterfront home. The party rocked until 4:30 a.m. It cost $3 million.  The 29,000-square-foot Five Star Island house in Miami Beach was rented out by Ernesto Bertarelli for his wife Kirsty's 40th birthday party. Although such rentals are illegal, the law is often ignored.  But the fact that it almost did not happen — that a judge had to decide on the very day of the event whether to allow it— has reignited an increasingly familiar debate here: When does someone’s really good time become the bane of someone else’s existence? Or, in the case at hand, did one billionaire homeowner rent out his mansion for another billionaire’s party in violation of a local ordinance?  “Kirsty’s Fabulous 40th Birthday Party,” as it was billed, was given last month by Ernesto Bertarelli, a Swiss billionaire ranked No. 64 on Forbes’s most-wealthy list, for his wife, a singer and a onetime British beauty pageant winner.  It was held on Star Island, a spot of land on Biscayne Bay beautified two decades ago by the developer Thomas Kramer, a lover of late-night bacchanals and no stranger to controversy. Mr. Kramer rented his estate, Five Star Island, to the Bertarellis for $40,000, a sum that barely covered his expenses, he said. The day before the party, a routine request to the Fire Department to have paramedics on hand caused the city to review the rental agreement, and then threaten to shut down the affair with a police roadblock.  That led to a court hearing in downtown Miami. At risk were the reputations of the rich and famous, Ms. Bertarelli’s feelings, the tempers of moneyed, jet-lagged guests, and Miami Beach’s tolerance for the whims of the wealthy.  “My wife’s 40th birthday will be ruined and forever remembered as a public disgrace to my family unless the party goes forward,” Mr. Bertarelli told the court, via affidavit, since presumably he was busy preparing for the event.  Summoned on a Saturday afternoon for a rare party-related emergency hearing, Circuit Judge Jose R. Rodriguez listened as lawyers explained that the Bertarellis had no idea their one-night house rental was illegal in Miami Beach, a claim that no one disputed. The judge, holding the ordinance to be ambiguous, swiftly dispensed with the case: The party should go on.  The mayor, Mattie Herrera Bower, is incredulous. “If you have enough money, you can get a lawyer to get a judge to break the law,” she said. “And I was unhappy about the precedent. We have a law for a reason, and everybody — even people with money — needs to obey it.”  At the center of the imbroglio is a Miami Beach ordinance that bans using a single-family home for commercial purposes, namely holding parties where money changes hands between the homeowner and the party host. The city passed the ordinance in 2008 after too many mansions were being used as ballrooms-for-hire, jammed with indiscreet partygoers who turned up the music, parked willy-nilly and raised the hackles of the Beach’s well-to-do residents.  But the law hardly halted the one-night party house rentals; in fact, the listings increased and the parties of out-of-town revelers bobbed below the city’s radar.  “During a certain period of the year, every other weekend something was going on: a launch for a vodka company, a launch for an automobile company, promoters with an after-party,” said Jorge Gomez, an assistant city manager for planning and zoning. “Hundreds of cars descending on the neighborhood, valet operations stashing cars all over the place — it really had a big impact.”  At the same time, owners began renting out their mansions for the night, the week or the month, a result, in part, of the drastic economic downturn. A trio of islands on the bay west of Miami Beach (of which Star is one) may bask in the glow of wealth, but that kind of luxury comes at a price. Ten of 34 properties on Star Island are now for sale, a record number, real estate brokers say.  Gloria Estefan lives across the street from Mr. Kramer. The estates of Sean Combs, a k a Diddy, and Rosie O’Donnell are nearby.
A lavish birthday party for a billionaireâs wife that almost wasnât shines a spotlight on the conflict between those for whom Miami Beach is a playground and those for whom it is home.