Boston Realty Advisors (BRA) has sold a 20-units building in the Back Bay for $3.8 million and an 83-unit building in Allston for $13.6 million.

The Allston property, 74-86 Brainerd Road, was sold to The Mount Vernon Co., a real estate holdings and development corporation. Mount Vernon already owns an adjacent parcel, as well as seven other properties in the neighborhood. 

Bruce Percelay, chairman of The Mount Vernon Co., said in a statement that the group plans to develop a master plan for its properties in the neighborhood.

"We have very exciting plans to transform this neighborhood," he said.

Christopher Sower, managing director of BRA, and Jason Weissman, principal and founder of BRA, represented the seller, Boston Brainerd Mass Limited Partnership. The Mount Vernon Co. was self-represented. First Republic Bank provided the long-term financing.

"The Mount Vernon Co. is among the largest privately held apartment owners in Massachusetts and is on a dramatic growth trajectory, having completed nearly $120 million in transactions in the last twelve months," said Sower in a statement. "Boston Realty Advisors has been excited to play a major role in Mount Vernon’s aggressive acquisition and disposition program."

The Back Bay property, 463 Beacon St., is currently run as a guest house. Sower and Weissman represented the seller, 463 Beacon St. Realty Trust. The buyer, Wenhua Jiang, was self-represented.

"463 Beacon St. has some impressive architectural detail," said Sower. "After a spirited bidding process, Ms. Jiang finally was awarded the deal."

"Our multifamily investment team was excited to sell this prestigious asset," said Weissman.

Brookline Bank provided the long-term financing.