In its second new development plan filed this month, the Archdiocese of Boston has proposed a two-phase supportive housing project in Dorchester.

The archdiocese's development arm, the Planning Office of Urban Affairs, filed plans in partnership with St. Mary's Center for Women and Children to renovate three buildings on the center's campus, the former site of St. Margaret's hospital, into supportive housing, according to the filing with the Boston Planning & Development Agency.

The center at 90 Cushing Ave. operates an adult family shelter, a young parenting living program, transitional housing, and education and employment support. The site is dilapidated with a "literally crumbling parking garage," which would be demolished under the proposal. The center said it has an operations plan mapped out to continue these programs during the renovation and construction, Banker & Tradesman first reported.

The first phase of the project would be the renovation of the east, main and chapel buildings, which make up the original St. Margaret's hospital and later additions. The renovation would create new living spaces for women and children experiencing homelessness. The apartments would consist of two-to-four-bedroom "pod-style" units, and the renovation would be financed by public and private funding.

The second phase would consist of the demolition of a parking garage and the construction of a new supportive housing building with 71 100% affordable two- and three-bedroom units, plus gathering spaces, playrooms and laundry rooms. The new development would increase the number of people at the shelter by 30%.

The St. Mary's Center has one other site called the Crossroads Family Shelter in East Boston, and it has proposed a 39-unit development in Roxbury. The center supports more than 500 parents and children across the two sites, according to the filing.

The archdiocese's POUA subsidiary has produced over 3,000 units of housing and poured over $650M in investment into Greater Boston, according to its website.

Earlier this month, POUA filed plans for another affordable and supportive housing project in Charlestown that would replace the former Constitution Inn. In March, the group, in partnership with the Fenway Community Development Corp., set out to buy Our Lady's Guild House, an affordable residential property for women in the Fenway neighborhood.