A historic building in Boston’s Innovation District will soon become a Marriott Residence Inn.

Quincy’s Lee Kennedy Co. recently mobilized on a full interior gut-rehab of 368 Congress St. The six-story building, originally constructed in 1900, is on Boston’s registry of historic landmarks.

The contractor worked with owner Norwich Partners Management, broker Colliers International and architect Group One Partners through a year of preconstruction services to convert the existing building into a 120-key Residence Inn.

As part of the preconstruction effort, LKCo. priced different concept scenarios and provided cost studies for numerous slab improvement options at grade level as well as the cost of window replication and replacement versus restoration. The project is expected to cost $32 million. Construction will be a full-gut renovation. The team will perform select demolition in the floors, walls and roof for structural and MEP upgrades; complete structural improvements to the ground floor slab; install all new mechanicals; replicate and replace all of the interior and exterior windows as well as the building’s prominent skylight; install two new exposed glass elevator cores in the open atrium and convert existing office space into guest rooms. Despite its new life as a hotel, the building will retain an industrial feel with exposed wood beams and ceilings as well as exposed brick in the atrium. The hotel is expected to open to guests in May 2013.