In spite of a recession and foreclosure crisis, the mayor presided over a boom in residential construction, encompassing everything from new aeries for the rich in Manhattan to disappearing vacant lots in the South Bronx. New York has added 40,000 new buildings since he took office, and the census counted an additional 170,000 housing units in 2010, up from 10 years earlier, more than any other city. Neighborhoods with the most growth: post-9/11 downtown; the West Side from Chelsea to Lincoln Square and Central Harlem in Manhattan; the Rockaways, Long Island City and Flushing, Queens; Williamsburg, Bushwick and Bedford-Stuyvesant, Brooklyn; the South Bronx.