Developer Millennium Partners has filed its latest plans for the downtown skyscraper, outlining a $1 billion tower that’s now short enough to clear the takeoff routes from Logan International Airport and cast a less imposing shadow on Boston Common — while still being massive enough to fit 1.6 million square feet of office space and luxury condos into about 48 floors.

The much-anticipated Winthrop Square Tower is back, with a new design, less height, and — perhaps — a bigger payday for the city.

The changes were detailed in an 1,801-page environmental report Wednesday to city and state officials, which will now kick off another round of public review of the long-planned project. But after months of debating shadows, studying height, and analyzing what might fill a building that would be the tallest in Boston’s Financial District, Millennium is aiming to start construction by summer.


“We’re very happy with this building at this point,” said Joe Larkin, who’s spearheading the project for the developer. “We hope people like it.”

In a concession to concerns from the Massachusetts Port Authority, this latest version of the tower measures 691 feet high, 84 feet shorter than what Millennium first envisioned. That would still make it the tallest building in Boston’s downtown core but would fit snugly below height limits along takeoff paths from Logan across the harbor, Larkin said. The Federal Aviation Administration is still reviewing the plan.

The lower height also means the building will cast a little less shadow on Boston Common and the Public Garden — the subject of contentious debates last year at City Hall and on Beacon Hill as the Walsh administration successfully pushed to change state laws governing new shade on the historic parks. The revised design meets the parameters set by the new laws, Millennium said, and at no time of the year will it cast shade on the Common after 9:20 a.m., or the Garden after 8 a.m.


“Because the building got a little shorter and its profile got a little thinner, the actual shadow impacts went down a bit,” Larkin said.

But it’s still a formidable building, nearly as big in square footage as 200 Clarendon — as the John Hancock Tower is now known — if not quite as tall.

The new plan will add 115,000 square feet of office space to the Winthrop Square tower — the size of a small office building itself — a move Millennium made to accommodate a wave of tenants looking for large spaces in downtown Boston. A report this week from real estate firm Colliers said more than 250 companies are in the market for a total of 6 million square feet of office space in the city, both records. Larkin said Millennium has been talking with potential tenants and, while it doesn’t have any deals signed, he is confident it will.

“The more we look at the office market downtown, and what we can offer, the more we think the market’s going to like it,” Larkin said. “We would have been disappointed in ourselves if we had decided not to go for more.”

There will be 26 stories of condominiums on top of the office space, which is how the city of Boston could collect even more cash from the project.

As part of its deal to buy the shuttered Winthrop Square Garage, Millennium agreed to pay the city $102 million upfront and $100 per square foot of condominiums, once they sell. The newest plan would put 640,000 square feet of condos in the upper floors of the tower, translating to $64 million for the city, or $13 million more than Millennium bid in 2015 to win the hotly contested project.


That cash has been a big selling point for the Walsh administration as it navigated the project through the shadow controversy. City officials argued the money justified changing state shadow laws last year and allocated the initial $102 million to parks and public housing across the city to help win support for the tower plan.

Still, there are a few details to iron out. Millennium says it will meet its affordable housing requirements by partnering with Asian Community Development Corp. on a new affordable building in or around Chinatown. They’re still looking for a site, but one possibility is a city-owned parking lot on Tremont Street, where the Boston Planning & Development Agency is seeking developers for a mixed-income apartment building. Millennium and Asian CDC are widely expected to bid on that project. Proposals are due Wednesday.

Tim Logan can be reached at tim.logan@globe.com. Follow him on Twitter at @bytimlogan.