Frank Keefe of the Keefe Co. has submitted a project notification form to the Boston Redevelopment Authority on behalf of the Center detailing the proposed project, which would be built within a 10-year master plan. The proposal involves developing three new buildings on a 1.85-acre parcel. The properties would include 300 residential units with 10% designated affordable housing. A 714-car underground garage is also proposed. The new buildings would be linked by a central atrium. In addition, the current medical/research building at the Joslin Center, One Joslin Place, would be renovated.

The proposed project would be developed in two phases, with phase one of the project focusing on constructing two new buildings, Two and Three Joslin Place and renovating One Joslin. In the PNF, Two Joslin Place is described as an 11-story, L-shaped building, while Three Joslin Place is described as a residential structure of "30 stories on top of the L-shaped building." Three Joslin will provide 327,000 sf of space and will be 434 feet in height. According to Meredith Bauman, spokesperson for the Boston Redevelopment Authority, the two separate addresses "will be 41 stories at one point." It's not clear, adds Bauman, what the height limit is in that area.

The first floor of Two Joslin will be used as retail space and the building will provide 300,000-sf of space and will be 140 feet in height. In phase two of the project, Four Joslin Place, a 22-story lab and medical office building that will be 300 feet in height, will be developed.