More than 265 affordable housing units are being proposed in a multi-building project at a former Boston State Hospital site. 

Developers of the final 10 acres of the former state hospital site in Mattapan and Dorchester filed a letter of intent with the Boston Planning & Development Agency outlining plans for an affordable housing community. 

The proposal for the Olmsted Village project includes the construction of six buildings in three different housing communities. 

Brooke House will be a six-story building with 127 affordable senior housing apartments with a ground floor community center and child care center. Treehouse at Olmsted Village will contain a four-story building with 60 affordable intergenerational apartments. 

Five buildings will bring homeownership opportunities to the project. They include a five-story building with 50 family mixed-income homeownership apartments; two three-story buildings with eight family homeownership apartments and two three-story buildings with 20 family mixed-income homeownership apartments. 

In December, Lena New Boston and 2Life Communities were provisionally designated by the Commonwealth of Massachusetts’ Department of Capital Asset Management to redevelop the final 10 acres. According to the filing, since 2015 Lena New Boston has developed 42 acres of the former state hospital land into 500 units of mixed-income family housing with both rentals and homeownership opportunities. 

The proposed project also includes community benefits such as a pedestrian and bike connection between Harvard Street and the Mass Audubon Boston Nature Center, a community shuttle to the Forest Hills MBTA station, and financial contributions to area community organizations.