Liberty Mutual Plans Back Bay Office Addition to Consolidate Boston Headquarters

Liberty Mutual has filed a letter of intent with the Boston Planning and Development Agency to redevelop part of its Back Bay headquarters at 157 Berkeley St. The plan calls for demolishing three brick buildings on Stuart Street and Columbus Avenue, which the company already owns. Those buildings include two restaurant tenants.

The project has two parts: a roughly 23,000-square-foot vertical addition above the eastern wing of the existing headquarters, and a roughly 62,000-square-foot, 10-story addition on an adjacent Columbus Avenue lot. Liberty says it would consolidate its Boston workforce into the new headquarters and vacate its other offices at 175 Berkeley St. and 30 St. James Ave. once construction is complete.

The company describes the effort as a way to create a cohesive campus for its employees and to anchor a long-term presence in the neighborhood. The filing is at an early stage, so timing and final approvals remain open.

For developers and lenders, the filing signals a large institutional campus project in a dense historic district, where demolition, height and design review will shape feasibility.