The Landmarks Preservation Commission is set to introduce a new South Village Historic District early next month—a move that will both appease preservationists and help grease the wheels for a massive mixed-use project nearby.

Organizations including the Greenwich Village Society for Historic Preservation have pushed the commission to landmark 10 blocks to the southern portion of the existing South Village Historic District, which is roughly bounded by Sixth Avenue, West Fourth Street, LaGuardia Place and Houston Street, called Sullivan-Thompson Historic District. And in late August, City Councilman Corey Johnson, the local representative for the area, made the district’s expansion one of the conditions for his approval of a proposed 1.7-million-square-foot project, St. John’s Center, set to rise at 550 Washington St., across the street from Pier 40 in Hudson River Park. That project, which is also supported by the Hudson River Park Trust and the de Blasio administration, needs City Council approval.

“If we are to approve the 550 Washington St. application, the city must also extend landmark protections to the historic blocks south of Houston Street,” said Johnson during testimony before the City Planning Commission.

The de Blasio administration supports the project for a number of reasons, though mainly because 25% of the proposed 1,586 apartments will be enrolled in the city’s affordable housing program. However, it needs Johnson’s vote, since the council typically defers to the local representative on land-use matters. Meanwhile, the Hudson River Park Trust wants the pending rezoning application to go through because it’s selling $100 million worth of air rights from Pier 40 to the developers, a team of Westbrook Partners and Atlas Capital Group. The trust plans to use the cash to repair the deteriorating dock.

By putting the South Village Historic District expansion on its to-do list, the city is meeting one of Johnson’s demands—something that the Bloomberg administration did in a similar situation in 2013, when the South Village Historic District was expanded from its the initial 2011 boundary in order to get former City Council Speaker Christine Quinn to sign off on a proposal to allow residential development in Hudson Square.

“The city had to be forced to [expand the district] in exchange for the Hudson Square rezoning,” said Andrew Berman, head of the Greenwich Village Society for Historic Preservation, which has sought to have the entire district landmarked for a decade. “Just like this time around.”

However, the designation does not guarantee that Johnson will give the St. John’s Center project a thumbs-up. While the developers have already made a number of alterations to the project in response to other community concerns, groups including Berman’s want to prohibit destination retail at the site. Johnson has also asked for a transportation study and permanently prohibiting the Hudson River Park Trust from selling more of its unused development rights to sites within Community District 2, which runs from the West Village in the north down to Hudson Square and Little Italy in the south, a move that would limit development in the district.

Hudson River Park is home to millions of square feet of unused development rights that exist on commercial piers. The trust plans to eventually sell some of those rights to the owners of upland development sites, though most of those rights are concentrated farther north in the park.