The Unitarian Universalist Association has sold three of its historic Beacon Hill properties to Boston developer Sea-Dar Construction, which plans to convert the buildings into luxury condominium units. The sale includes the association's longtime headquarters at 25 Beacon Street and the adjacent Pickett and Eliot Houses at 6 and 7 Mt. Vernon Place.

The properties, which sit directly beside the Massachusetts State House grounds, attracted significant interest during marketing. Real estate advisors said more than 170 parties signed nondisclosure agreements and 18 bids were submitted after the buildings hit the market.

Sea-Dar, a firm known for converting older Boston buildings into residential units, is expected to create six or seven full-floor luxury condominiums at 25 Beacon Street. The Pickett and Eliot properties will likely be developed into smaller condo units or duplexes. Because Beacon Hill is a protected historic district, the exteriors must remain largely unchanged, though interiors will be fully rebuilt.

The Unitarian Universalist Association will relocate to 24 Farnsworth Street in the Seaport District. Staff cited aging infrastructure at the Beacon Hill buildings, including unreliable elevators, outdated wiring, and poor climate control, as motivating factors in the move.