Photo courtesy of Google Maps.

A South Boston office building across the street from a large proposed development has sold for $28.85 million, according to documents filed in the Suffolk Registry of Deeds.

The Transorg Corp. sold 7 Elkins St. to an affiliate of New York City-based Mack Real Estate Group.

The 19,440-square-foot, 4-story building was built in 1945 as a warehouse and is assessed at $1.19 million, according to city property records.

The building sits across Summer Street from a 1.78 million-square-foot project proposed by Redgate Capital Partners and Hilco Redevelopment Partners on the site of the former South Boston Edison power plant. That project will feature 636 residential units, plus office, residential, hotel, retail and restaurant spaces.