WinnCos. is pitching a massive redevelopment of a public housing community in South Boston, laying out ambitious plans to replace more than 1,000 dated residential units.

The developer Monday submitted a letter of intent with the Boston Planning and Development Agency for Phase 1 of the redevelopment of the Mary Ellen McCormack public housing project. The project, in partnership with the Boston Housing Authority, would replace the 30-acre community’s existing 1,016 units with 1,370 mixed-income units. Phase 1 of the project will now undergo BPDA review.

“Residents [now] are essentially living in micro units at every household size, with little to no amenities,” WinnDevelopment Senior Project Director Andrew Colbert said in an email Monday. “It’s safe to say the new construction apartments will be approximately 20-to-30% larger than the current small unit sizes.”

Units currently average 566 SF for a one-bedroom up to 966 SF for a three-bedroom townhome, Colbert said. The existing apartments lack laundry, air conditioning, elevators and accessibility, a WinnCos. spokesperson said.

The $1B Phase 1 calls for eight new towers between five and 19 stories tall. WinnCos. anticipates no relocation for residents during construction of the project’s first tower, and said its construction timeline would minimize required off-site housing.

Phase 1 and Phase 2 combined would deliver 18 new structures and 2.3 acres of open space. The developer would also raise grades to accommodate storm surges, sea-level rise and support new roadways and other pedestrian infrastructures. Boston-based architectural firm CBT will serve as the redevelopment’s master planner.

WinnCos. also plans to include up to 44K SF of retail, including a corridor between Andrew Square and Joe Moakley Park. Residents want a pharmacy, grocer, full-service bank and childhood education center, and the developer would prioritize small, local, minority and women-owned businesses, Colbert said.

Six hundred new market-rate units are proposed, which would reduce public subsidies needed to replace affordable housing units, the spokesperson said, while 200 middle-income units with rents affordable to those making 100% of the average median income would be constructed should funding make it feasible. Tax credit programs will dictate a maximum AMI of 60% for affordable units, while a Housing Assistance Payment contract by the BHA will allow tenants to pay 30% of their income toward housing costs with the contract paying the rest.

“That’s what enables households with lower incomes to have the opportunity to live in this community,” Colbert wrote.

WinnCos. secured redevelopment rights to the community in 2017 and developed plans with community and city officials including the Mary Ellen McCormack Task Force, a resident-elected representative group for the housing complex. Funding will be sought in coordination with WinnCos.’ financial partner, the AFL-CIO Housing Investment Trust. The city of Boston will also contribute $50M in funding for the project.