BOSTON — Russian millionaire Valery Kogan's plans for a 5,000-square-meter mansion in Greenwich, Connecticut were voted down by a city board after neighbors objected that the house, which would have had 26 toilets, would be too big.

Kogan and his wife, Olga, wanted to raze the 1,850-square-meter home on the site, which they bought in 2005, to make room for a house almost three times as large, with two wings and space to park 12 cars.

Kogan, chairman of East Line Group, which operates Domodedovo Airport, has a net worth of $600 million, according to the February issue of Finans magazine. Kogan and his wife also own homes in Manhattan and California.

The Greenwich Planning and Zoning Commission voted last week to reject a permit for the project, which would be the largest single-family home built since the New York suburb began reviewing plans in 2001.

"Thank God," Charles Lee, who lives across the street from Kogan's property, said after the board voted 3-2 in a meeting room filled to capacity with onlookers. "What we're really pleased about is they used the power the community gave them to support the community. We are delighted."

Even in Greenwich, where the average price of a home is $2.8 million and many houses qualify as estates, residents complained that Kogan's proposal was excessive. A petition signed by 175 people said the size and scope of the project was out of sync with the character of the neighborhood.

If the board had granted Kogan a permit, residents were prepared to go to court to block it, Lee said in an interview before the meeting.

Greenwich, 43 kilometers north of New York, is the hedge fund capital of the United States, with more than 60 funds that occupy 80 percent of its commercial property.

Kogan's house would cover around half of the 2.8-hectare lot, design plans show. The house would have 2,500 square meters above ground, in compliance with the town's limit. The rest of the space, almost half the total, would be underground.

"It looks like they want to duplicate the Winter Palace here in Greenwich," Leslie McElwreath, 45, who lives one street over said before the decision.

Planning commissioners expressed concern that the facilities in the house, including the more than two dozen toilets, suggested that the Kogans planned to entertain large numbers of guests, overwhelming narrow Simmons Lane.

"While we have had projects submitted in the past that have had game rooms, billiard rooms, pools, wine cellars, locker rooms, libraries, etc., this is the only one I can recall that had them all," board member Richard Maitland said.

He and one other panelist who voted to move the project forward set dozens of conditions that would have required a complete redesign.

Helen Higgans, executive director of the Connecticut Trust for Historic Preservation, said in a letter read into the record that destroying the existing house would "obliterate forever" the "idyllic landscape" of the original Simmons estate.

The Kogans' lawyer, John Tesei, sounded upbeat about the result.

"I fully expect that the client will work on an application that will address all the issues," he said. "We wanted to hear all the issues."

Tesei said his clients were intent on building on the property.

Greenwich has several homes with more aboveground square footage than Kogan envisions for his, but they were built before reviews were required for permits, town planner Diane Fox said.

The couple recently bought five houses in Caesarea, on Israel's Mediterranean coast, with the intent of tearing them down and building a $50 million home, Haaretz newspaper reported.