This renovation and combination of two apartments occupying several stories of an Upper East Side townhouse derived its design logic from the idiosyncratic sectional condition of the existing architecture. The original nineteenth-century structure was previously converted into separate units, a process that resulted in divergent floor levels on the north-facing (street-front) and south-facing (garden) sides of the building. Within a limited square footage (roughly three thousand square feet), the apartment included six distinct floor elevations. The challenge was to reconfigure and integrate these discrete levels and separate units into a single functioning residence.The zone between the divergent halves was conceived as a spatial joint or splice, negotiating the multiple elevations and interweaving the public and private circulations. The primary feature of this interstitial zone is a slatted-wood and blackened-steel screen wrapped by an interconnecting stair. The stair and screen physically link the different levels of the public program while strategically arranged voids allow for visual transactions between the stacked spaces. On the garden side, a spiral stair encased in a perforated steel cylinder similarly connects the private floors. The continuity of these vertical elements provides coherence to otherwise discontinuous and fragmented spaces.