Charleston, South Carolina-based apartment developer Greystar has acquired an Arsenal Street parcel for $21.2 million.

The 6-acre site recently received approval for a 282-unit apartment complex.

Building supply wholesaler M.J. Pirrolli & Sons occupied the site for over 60 years and put the three parcels on the market in 2012, attracting interest from developers on behalf of retailers and multifamily owners. Industrial sites in the inner-ring suburbs have been in increasing demand among multifamily developers with a dwindling number of large development parcels available.

Designed by The Architectural Team of Chesea, The Elan complex also will contain 10,000 square feet of retail space and a half-acre park. The Watertown zoning board of appeals granted a special permit for the project in July.

A spokesman for Greystar did not return messages seeking additional details this week. The company manages approximately 400,000 apartment units and has a $3.4 billion development pipeline.

The site at the corner of Arsenal and Irving streets is a mile west of the Arsenal Project shopping mall and Athenahealth headquarters, two properties that are in the midst of permitting for major redevelopment projects.