Earlier this year, developer AAC Group pitched the idea of transforming 320 acres in College Park, Ga., into an “Airport City” with 3.5 million square feet of construction, but now city officials are calling for the project to entail at least 7.5 million square feet of new construction. The city’s call for increased density could bring the total cost of the project to more than $3 billion. Read the Curbed/Atlanta story here