In the middleof the last decade, New York came up with a plan to upgrade two of its aging public schools and to lease the valuable air rights above them to a condo developer. Two years after breaking ground, the first phase of that massive project is completed—a new 385,000-sq-ft school building that houses Public School 59 and the High School of Arts and Design under one roof. (The condo tower is up next for the mixed-use project, which media reports peg at about $700 million.)