A rendering of the proposed Lincoln Yards. [Department of Planning and Development]

The massive Lincoln Yards development will advance to the City Council’s Zoning Committee on Thursday after aldermen, planning officials and developer Sterling Bay announced an agreement to double the amount of housing for poor and low-income Chicagoans built as part of the development.

The deal, announced Tuesday, would require 600 units of affordable housing to be built on site, according to the deal announced by 2nd Ward Ald. Brian Hopkins. Originally, the plan called for only 300 units to be built on site, a plan criticized by several alderman as insufficient.

“This is a huge gain,” Hopkins said at a City Hall news conference to announce the plan.

Although the $6 billion development has consistently been supported by Mayor Rahm Emanuel and Hopkins, new Zoning Committee Chairman Ald. James Cappleman (46) said he wanted the proposal to be revised to provide housing those making no more than 30 percent of the area’s median income, or $25,450 for a family of four.

The Uptown alderman replaced disgraced Ald. Danny Solis (25) as chairman of the Zoning Committee in January. Cappleman faces scientist Marianne Lalonde in the April 2 runoff to win a third term on the City Council.

Mayoral candidates Toni Preckwinkle and Lori Lightfoot have called on aldermen to halt consideration of the project, which could be approved by the time the next mayor takes office in May, tying her hands.

Eleven aldermen told The Daily Line in January and February they would vote against the project unless it included more affordable housing than originally proposed.

Although the 55-acre development is in the 2nd Ward, it is sandwiched between the 43rd Ward and 32nd Ward. Ald. Michele Smith (43) and Ald. Scott Waguespack (32) vehemently oppose the project, and have been urging its delay.

However, under aldermanic prerogative — the city’s unwritten policy of giving aldermen the ultimate authority over projects in their own wards — the project only needs the support of the mayor and Hopkins.

Hopkins has said the new roads, bridges and sidewalks set to be built as part of the Lincoln Yards development are urgently needed.

Department of Planning and Development Commissioner David Reifman said the approval of Lincoln Yards is critical to ensure Chicago’s economy remains robust as the city transitions from its industrial past into the future.

“This is a tremendous opportunity for jobs and economic growth,” said Reifman, who briefed aldermen Tuesday on the revised proposal. “I don’t know any other way to develop this site and have it come close to its potential.”

Reifman rejected concerns that the project has been rushed — but said time was of the essence.

“If they don’t get out of the box, we might be waiting an inordinately long time to develop this land,” Reifman said.

The development is expected to create 10,000 construction jobs and 24,000 permanent jobs, according to city officials. Under the city’s rules, $1.9 billion of the project’s cost will be set side for women, African American and Latino owned firms.

If approved by the Zoning Committee, the full City Council could act on the proposal March 13.

Cappleman could not immediately be reached for comment. Hopkins said he could not say whether Cappleman supports the revised plan.

The project relies on a $900 million subsidy, set to be generated by the 168-acre Cortland and Chicago River Redevelopment Area (F2018-72), which could also be approved by the City Council on March 13 if it is endorsed by the Finance Committee on March 11.

TIF districts capture all growth in the property tax base in a designated area for a set period of time, usually 20 years or more, and divert it into a special fund for projects designed to spur redevelopment and eradicate blight.

Of the 6,000 apartments, condominiums and townhomes planned for Lincoln Yards, 1,200 must be set aside for low- and moderate-income Chicagoans. The total number of affordable homes will not increase under the revised proposal — only their location will change.

That is an “outstanding commitment” by a private developer, Reifman said.

Sterling Bay also plans to pay $39 million into the city’s housing trust fund. Half of the trust is earmarked to subsidize individuals’ rent in existing buildings, and the other half is set aside to build new homes for the poorest Chicagoans.

Another 300 units would be allowed to be built outside the development, but within three miles, according to the revised plan. Sterling Bay would also have the option to pay into the trust fund instead of building some of those remaining units, or including them as part of Lincoln Yards.

The 600 affordable units built as part of Lincoln Yards would be earmarked for low- and moderate-income Chicagoans making no more than 60 percent of the area’s median income, or $47,400 for a family of four, according to city data.

Ald. Walter Burnett (27) and Ald. Raymond Lopez (15) praised Hopkins for increasing the number of on-site affordable homes.

“This is a great development,” Burnett said.