When PMC Property Group decided to redevelop a 350,000-sq-ft former industrial building at 2400 Market Street in Philadelphia and add 300,000-sq-ft of office space above it, they knew they stood on solid footing. The massive concrete facility built around 1920 was originally designed as an automotive warehouse. It was designed to handle heavy loads, but the space, built on a diagonal grid with large interior ramps for moving vehicles throughout the building, didn’t lend itself to office or retail use. To integrate construction with the existing building required numerous structural upgrades, including transferring, removing and retrofitting columns that were approximately 100 years old.
“It was so structurally sound, it was no problem adding five stories,” says Jay Persico, project manager at Fastrack, PMC’s project-management arm. But Persico notes that the team did need to add a new column grid on top, to normalize the pattern.