A long-debated plan to add more than 1M SF of mixed-use development at the end of the Green Line in Newton has finally picked up steam.

Mark Development and the Newton Lower Falls Improvement Association reached a compromise for the developer to build a just over 1M SF development at Riverside Station at the end of the Green Line’s D branch. Sixty percent of the project would be earmarked for housing, which translates to roughly 600 apartments, 100 of which would be affordable units.

The overall project is smaller than Mark Development CEO and founding principal Robert Korff's original plan to build 1.5M SF at the site, the Boston Globe reports. Normandy Real Estate Partners originally floated a 600K SF plan for the property in 2013 but later withdrew it after saying it didn’t pencil out financially.

Building plans have scaled back from an earlier plan to go as high as 18 stories. The tallest building currently proposed is a 150-foot office building. But the residential component is up from a prior 1.2M SF plan that would have had 45% of the project devoted to housing.

A representative of the Lower Falls Improvement Association told the Globe the housing boost was a key motive in the organization throwing its support behind the new plan.

Mark Development still needs a two-thirds majority vote from the 24-member Newton City Council. If the developer gets all approvals needed, construction is expected to get underway by late 2020.