Occupancy summer 2017. Sprawling three bedroom, three bath duplex residence with direct elevator entry and northern exposure overlooking historic Franklin Street. The soaring 232 double height main living area creates a dramatic room with airy, light-filled volume, enhanced by dual sets of massive 6x9 windows.  Interiors, custom-designed by Shigeru Ban, complement the light, open design with grand room proportions and flexible living spaces including a large library/bedroom with full bath, and second level study overlooking the main living area below.  The kitchen, which opens to the 290 x 280 great room, features custom white matte lacquer cabinetry, polished Calacatta Lincoln slab marble countertops, Gaggenau gas cook top with externally vented hood, Gaggenau refrigerator in custom white matte lacquer finish, Gaggenau steam oven, Gaggenau under-counter wine cooler, and Dornbracht fixtures. Upper level bedrooms feature 1010 ceilings. The five fixture master bath features a custom Corian vanity with fully incorporated, Bianco Dolomiti marble walls and floors, 71 Kaldewei Classic Duo Oval soaking tub, thermostatic temperature control, and radiant heated floors.  5 wide plank white oak flooring throughout. Year-round multi-zone heating and air conditioning; side by side Miele washing machine and externally vented dryer; 100 sq ft private storage unit included with residence. Cast Iron House offers an array of contemporary comforts that make use of the buildings preserved 19th century vaults, allowing natural light to filter in. The building features a 24-hour doorman, large fitness center, yoga studio, courtyard with living green wall, sauna, steam room, treatment room, custom water room, resident lounge, play room and bicycle storage.