The 1.7 million-square-foot redevelopment of the former Edison power plant in South Boston will bring nearly $20 million in community benefits including upgrades to MBTA service in City Point, and new public parks on Boston Harbor.

Boston Planning & Development Agency directors approved the L Street Station project Thursday, culminating a nearly four-year review that extracted a series of concessions and redesigns for the 15-acre property at 776 Summer St.

Developers Redgate Capital Partners and Hilco Redevelopment Partners plan 860,000 square feet of office and R&D space, a 240-room hotel and 636 residential units. The project includes 80,000 square feet of retail space, 10 percent of which will be offered at discounted rents to local and disadvantaged businesses.

U.S. Rep. Stephen Lynch, D-South Boston, weighed in during the virtual meeting to offer his support of the final version, including a reduction in housing units. Developers originally proposed over 1,300 housing units, which attracted objections from Massport which operates the neighboring Conley Container Terminal.

“I saw a bit of incompatibility in the original proposal, where you had residential right up against the cranes and trucks, and it would have been an unhappy relationship,” Lynch said. “This seems to be a buffer between the project and the industrial port.”

Developers agreed to set aside 16 percent of residential units as income-restricted, exceeding the city’s 13 percent minimum, and include all of the affordable units on-site.

But a housing advocate said the affordability component still falls short, citing more aggressive strategies offered by developer Accordia Partners at its proposed Dorchester Bay City project.

“The elderly are our most vulnerable residents. The pressures of the housing market on them are tremendous and heartbreaking, and this project is doing very little to limit the displacement of residents,” said Donna Brown, executive director of the South Boston Neighborhood Development Corp.

Brown noted that Accordia, which proposes 1,760 housing units, has offered to pay $10 million to an anti-displacement fund that would provide assistance to first-time homebuyers in Dorchester.

BPDA directors unanimously approved the project, which retains four of the turbine halls from the power plant decommissioned in 2007. The master plan designs by Stantec retain nearly six acres of open space, including a 2.5-acre waterfront park.

Community benefits include a $10-million contribution toward transit upgrades, $1.75 million for improvements to Medal of Honor Park and Christopher Lee Playground, a $1 million perpetual scholarship endowment for South Boston college students, commitments for trade apprenticeships and internships throughout the duration of the development, and 120 free parking spaces for South Boston residents on nights, weekends and during snow emergencies.