KS Partners received permission to convert 262 Washington St. and the adjoining 85 Devonshire St. buildings to housing in 2024. Photo by James Sanna | Banker & Tradesman Staff

KS Partners completed the $8.6 million sale of a downtown Boston office property that’s approved for a 95-unit residential conversion.

Charlestown developer Greg McCarthy was the buyer, according to a Suffolk County deed. The 85 Devonshire St. site received approval in 2024 for an estimated $36 million conversion project. 

KS Partners hired Boston-based Embarc Design as architect for the project, which includes three adjoining buildings completed from 1908 to 1920.

The Boston Planning & Development Agency approved the project in 2024, but the property was placed up for sale through online auction site Apex Commercial Exchange in June.

The project includes 85 Devonshire St., 4 Water St. and 258-262 Washington St., which range from 6 to 11 stories. One-bedroom apartments averaging 682 square feet will comprise the majority of the units.

The property also includes nearly 16,000 square feet of retail space.

McCarthy also is converting 129 Portland St. in the Bulfinch Triangle and 615 Albany St. in South End into a combined 49 units.

In August, Boston’s office to residential conversion program received its largest application to date.

New York-based Vanbarton Group submitted plans for up to 490 apartments in an estimated $410 million conversion of 31 St. James Ave., an 11-story office building.

Qualifying projects receive 75 percent property tax abatements for 29 years. More than 430 housing units are under construction, out of a total 2,331 units in 36 buildings that have submitted plans.