"And many of the approvals are not assured," Nutter said. The Goldenberg team, for instance, wanted to add a floor to the four-story structure.
Unlike the competing projects, the $90 million Kimpton proposal would require no public investment.
Alan Greenberger, deputy mayor of economic development, said the others wanted a "significant" amount of public financial support. The Kimpton plan "is the straightest path to success," Greenberger said.
This would be the third Center City hotel for Kimpton, which recently converted the Architects Building on South 17th Street into the four-star Hotel Palomar and the Lafayette Building near Independence Hall into the equally swank Hotel Monaco.
The selection, however, drew criticism from City Councilman James Kenney, who called it "a tremendous missed opportunity."
"This choice creates the fewest jobs, fewest new hotel rooms, and provides only half the tax revenue," Kenney wrote in a memo to his colleagues. He favored Goldenberg's plan to develop a 356-room, $170 million Fairmont Hotel at the site.
"The Champs-Elysées of Philadelphia should have a Fairmont," Kenney said in an interview.
"That's not a boutique building," he said of Kimpton's plan. "I don't think the project lives up to the grandeur of the building."
The courthouse, a New Deal project that opened in 1941, is on the Philadelphia Register of Historic Places. It is designed to evoke the Hotel Crillon on the Place de la Concorde in Paris, and the interior is adorned with 37 murals also considered protected cultural relics.
David Searles, president of the Logan Square Neighborhood Association, welcomed the announcement. "We're very happy to see the property developed into something very useful," Searles said.
In recent years, private development in the Logan Square area has steadily risen. To date, about $479 million has been committed for retail and residential developments.
Paul Levy, executive director of the Center City District, called the neighborhood "a textbook case" of leveraging public investment in projects such as the Barnes Foundation and Sister Cities Park to yield private investment.
"It took an already attractive area, put a spotlight on it, and created a lot of interest and energy," Levy said.
For the Kimpton project to move forward, City Council will have to approve conveying the property to the Philadelphia Authority for Industrial Development. The Peebles group, including local developer P&A Associates, would buy the property for $4.5 million.
The $90 million cost of the project would be financed in part with $30 million in equity from McFarlane Partners, a minority-owned real estate investment management company based in San Francisco. The rest would be raised through debt and loans.
Once Juvenile Court moves to a new building at 15th and Arch Streets, it would take about 18 months to convert the space into hotel rooms, banquet space, a spa, and restaurants.
Inquirer staff writer Troy Graham contributed to this article.