Located in the city’s heavily populated theater district, this project was considered the largest and most complex demolition and abatement in downtown Boston’s history, according to the team.

Logistically challenging, the project’s scope included the abatement and interior gut-out of 250,000 sq ft of a 12-story building; removal of roof penthouses and 14-ft parapet walls; facade removal from the third floor through the 12th floor; and structural demolition on those floors, according to NASCI LLC, which 100% self-performed all demolition and abatement.

The team says it was limited to an outside loading area wide enough for only one truck at a time with no additional space to store or package debris.

NASDI packaged materials on the building’s floors and moved packages outside with hoists so they could be loaded on trucks in a maximum allowable time of 45 minutes, crucial for delivering the project on time and within budget.

Work on the parapet involved lowering 5-ton granite pieces onto the roof one at a time using a modified mini excavator placed on the roof, the team says.

Once the excavator was on the roof slab, the parapet pieces were downsized using a Brokk demolition machine, then placed on electric carts and lowered to the ground using a manned hoist.

NASDI says the “key to the success” was the team’s collaboration and “detailed planning to identify when and how” to take each step in the project.