An affiliate of Carpenter & Co. plans to build a 65,000-square-foot office building in Harvard Square.

Carpenter, which owns the nearby Charles Hotel, recently purchased the property at 114 to 116 Mt. Auburn St. from the Bulfinch Cos.

Carpenter now owns the entire block between Mt. Auburn and Bennett streets. The property sits on 5,000 square feet of land and abuts properties previously purchased by Carpenter from the MBTA. 

"We intend to build a … LEED-certified office building on the site and to restore the historic MBTA ‘Conductors Building’ on the balance of the block," Richard Friedman, president of Carpenter & Co., said in a statement

The six-story Mt. Auburn Street property was previously occupied by a Chili’s restaurant and is currently vacant.