A developer submitted a proposal to transform a six-story office building at 95 Berkeley St. into about 92 residential units. In a letter of intent, the developer, 95 Berkeley OTR LLC, shared basic plans for a mixed-use redevelopment of the 87,000-square-foot South End building.

Eighteen of the residences would be classified as affordable, while the remainder would be market rate. The ground floor would retain its existing office tenant, as well as up to 1,700 square feet of retail space, according to the proposal, which notes the building has a 36-space underground parking deck.

The proposal is subject to Boston’s Large Project Review process, as well as approval from the city’s Zoning Board of Appeals and South End Landmark District Commission.