In February, shortly after Menino issued the challenge asking for proposals to build a 1,000-ft tower, the city's tallest, city officials said they were besieged by calls from developers as far away as Europe and Asia inquiring about the project. In October, 10 local and three out of state builders picked up proposal packages from the Boston Redevelopment Authority. Chicago-based Equity Office Properties Trust was among the potential developers. The company owns a high-rise office tower next to the 115 Federal St. garage.

Belkin, however, was the only businessman to enter a proposal. Beyond the building, his plan calls for a one-acre, ground level public park and a 20,000-sf public garden on the building's roof. Italian architect Renzo Piano designed the building. "Today's proposal promises everything we asked for," Menino says in a statement.

David Begelfer, head of the local chapter of the National Association of Industrial and Office properties, tells GlobeSt.com it was no surprise Belkin was the sole respondent, given that he also owns an adjacent property at 133 Federal St. which he can combine with the garage parcel.