
The marble lobby at CitySpire, a skyscraping 72-story tower in Midtown, bustles with rushing people bundled against the cold. Nattily dressed doormen hail taxis and see to a constant stream of deliveries.
Yet the mixed-use building — the first 23 stories house offices — is not as crowded as it appears. CitySpire, at 150 West 56th Street across from Carnegie Hall, is one of the least occupied buildings in Manhattan, with more than 60 percent of its residential floors made up of investment properties and pieds-à-terre, according to data from the New York City Independent Budget Office.