A half-mile stretch of road could be the key that unlocks one of the biggest development sites in Greater Boston.
That's what builders and state and local officials say about a half-mile extension of the road inside the former South Weymouth Naval Air Station, now the site of a 1,400-acre, $2 billion, mixed-use development.
Long a white whale, the project — known as Southfield until it was recently rechristened Union Point — has been stalled for years, despite the white-hot real estate market around Greater Boston. It has been delayed in part because there's no way to get from one side of the development to the other. There is an access road from Route 3 on one side, and another from Route 18, but nothing connecting the two in the middle.
Now, for $6.7 million in state money, that's set to change. On Thursday, officials lead by Governor Charlie Baker will be in Weymouth to break ground for the road.
"It has been a reminder of the unfulfilled promise of this place," said Kyle Corkum, managing partner at LStar, a North Carolina developer that bought the project last year from Starwood Land Ventures. "Simply opening up the road makes possible a lot of commercial development that wouldn't happen otherwise."
The state spent nearly $45 million in 2011 building a 1.8-mile parkway from the eastern side of the vast former air base, which straddles parts of Weymouth, Rockland, and Abington. But the road abruptly ends at a mostly abandoned section of the old base so desolate that it's now used for movie sets. A half-mile away is another road that connects to the South Weymouth commuter rail station and busy Route 18.
While hundreds of single-family homes have been built in recent years around the edges of the project, the middle of the site remained hard to reach, a ghost town of old hangars and barracks and tarmac. That left the state paying $1.9 million a year to cover debt service on bonds for the existing road, funds that were supposed to come from new tax revenue from development.
Closing the gap has long been the goal, but paying for it has proved hard. Starwood was pushing the state to come up with $20 million to $40 million to finish the parkway and to build a flyover over railroad tracks and improve entryways to the project. While state officials were supportive, they balked at the price tag.
"The extension at a reasonable price made sense," Baker said in an interview. "But the $40 million number was a nonstarter."
Last year, Starwood, which had taken over the project in its much larger 2013 purchase of the developer LNR Property Corp., sold it to LStar. The new developer went back to the state and they quickly agreed on a simpler road, with a price tag of $6.7 million.
"It didn't take a lot of convincing," said Baker, who will preside over the groundbreaking Thursday.
There have been other changes.
This spring, all three towns adopted zoning rules that will enable vastly more commercial development — millions of square feet of multifamily housing and office buildings as high as 10 to 12 stories — in what had been envisioned as mostly single-family subdivisions.
The plan now, Corkum said, is to create a mixed-use hub for the South Shore, with a town center, walkable neighborhoods, and, eventually, enough office space to match what's in Cambridge's Kendall Square, perhaps two times over.
"We could have sold that [housing] overnight," Corkum said. "But we knew we had a chance to do something so good, so transformative to the region."
LStar is also close to a deal with Weymouth that would bring more water to the site, enabling more development faster. Mayor Robert Hedlund said that could be signed within days.
"This will really unlock the potential of the site," Hedlund said. "They've been hamstrung."
With the road plan, the water and the rezoning, the project has sparked strong interest from companies looking for more space — or less-expensive space — than they can find in central Boston, Corkum said. He expects to announce several major commercial tenants soon and is in talks with an "enormous" office user that would bring hundreds of well-paying jobs.
"That would not have been possible without this road," Corkum said.
It will still take at least a decade to build out Union Point, Corkum estimated, perhaps longer.
But after 20 years of waiting for something big to happen there, Hedlund is looking forward to some real progress, he said.
"The momentum is finally here," he said. "I think you're going to see everyone's vision for this place finally come to fruition."