The architecture for the roof terrace of this 1960s townhouse spans the three levels of this duplex. DFA conceived of a spiral ribbon staircase, which would connect each level of the narrow apartment, and house various programmatic components necessary for this compact Manhattan home. On the bottom level, the staircase incorporates shelving to affix the living room’s AV system, and shopped sheet metal extends outward to create a work desk on the second level. On the roof, the metal structure extends upward and outward to create a wet bar, and an awning overhead.