This former artist’s loft in Soho combines two duplex apartments into one 7,000sf living space. An elegant, floating staircase constructed of three-inch thick limestone treads allows light to permeate from floor to floor. Adjacent to the stairs is a 26-foot tall glass wine vault which extends between the two stories. Supported by a custom cold-rolled steel framework, the vault includes full-height millwork designed to accommodate a library of 1,500 wine bottles and display cabinets. A clear glass catwalk allows access to the upper wine cabinets from the apartment’s penthouse level.