Porsche Cars North America has opened its new headquarters near Hartsfield-Jackson International Airport.

Employees moved into the new building Tuesday, relocating from their old headquarters in Sandy Springs, Porsche Cars North America general counsel Joe Folz said. Roughly 300 are now in the new facility by the airport off I-75, he said.

The facility’s test track isn’t yet complete, but is expected to begin operations by early April. When it is up and running, the headquarters and “customer experience center” will have about 450 employees, Folz said.

The company back in 2011 announced plans to build the new headquarters and had originally expected to move in late 2013.

But, “it was a very complicated building and a very complicated site,” Folz said. “We underestimated the time it would take.” Grading took longer than anticipated when plans for the track became more elaborate, he said.

The track is delayed because a module that will simulate icy driving requires specially-treated pavement with polishing and epoxy surfacing, which will require several consecutive days and nights of warmer weather, Folz said. The track is set to be finished in February, then instructors will develop curriculum before opening the Porsche experience center for operations in the spring.