In addition to a state-of-the-art convention center that would be 3.1 million square feet rather than the 1.8 million at Javits, the platform and adjacent rezoned areas would provide the foundation for a dynamic new neighborhood, accommodating nearly 14,000 new units of housing, of which about 50 percent would be affordable; more than two million square feet of office and retail space; several hotels to support convention visitors; vast expanses of public green space; a job-creating technology campus; and a new transit center. Convention visitors would have convenient places to stay at affordable rates.

One objection might be that a convention center must be in Manhattan to attract blockbuster conferences. Let’s put that old way of thinking aside. The ExCeL exhibition center in London, about five miles from the city’s core, has catalyzed nearly $5 billion in economic impact and supported 31,000 jobs. Sunnyside Yards is far closer to Midtown.

The land under the Javits Center would be rezoned for housing. More than 11,000 units could be developed there, of which 20 percent would be affordable. Between the redevelopments of the Sunnyside and Javits sites, more than 25,000 units of desperately needed housing could be created, of which more than 9,000 would be affordable. That could make a major contribution to Mayor Bill de Blasio’s admirable and ambitious housing plan.

Getting anything done in New York is hard. The bigger it is, the harder it gets. And the Javits to Sunnyside move is very big. Total estimated costs for the platform, the convention center and the related open space and infrastructure would be about $8 billion, according to an analysis done for me by SHoP Architects and HR&A Advisors. But the beauty of this plan is that it can all be financed at no new net cost to taxpayers. The Javits property could be sold for about $4 billion. The incremental real estate tax revenues from the new developments on both the Sunnyside and existing Javits sites would roughly pay for the difference.

Almost all of the land required to make this happen is owned by either the State of New York or by Amtrak. The Amtrak chairman, Anthony R. Coscia, indicated recently that Amtrak was considering the development potential of its holdings in the Sunnyside Yards. Still, it is Gov. Andrew M. Cuomo who controls all of the Javits site and much of the portion of Sunnyside Yards not owned by Amtrak.

Too often in New York, we get stuck in the tired paradigm of choosing between development and affordability. If we plan smartly, development can finance affordable housing, and affordability will attract greater diversity, which makes the city even more appealing to new residents and businesses.