Manhattan residential space is a premium commodity, so precious little goes unexploited. But in remaking this Upper West Side pied-à-terre, architects Scott Specht and Louise Harpman solved a 3D puzzle that was challenging even by neighborhood standards. “The existing footprint was only 320 square feet, but it stretched vertically for approximately 25 feet,” Specht says. The existing layout was so awkward, “there wasn’t even a reasonable place to locate a bed or a couch.” That called for a radical approach, he says, “so we stripped the entire thing, including ripping off the bulkhead that went up to the roof.”

Specht and Harpman organized the resulting volume with a new scheme that spirals upward through four levels, from kitchen to living room to sleeping loft to an outdoor terrace planted as a green roof. Black-stained wood floors contrast with white walls and cabinetry, leading upward along the top edge of a storage staircase inspired by Japanese tansu chests. The roof-access wall spills daylight through the entire apartment, and because each space opens onto at least one other, the layout dispels any sense of confinement. The only interior door, Specht notes, is at the bathroom.

“Every piece of this apartment is functional,” observed one judge. “It borrows space from every direction—sideways, up, and down—so it lives like something twice the size.” Another judge added, “the whole project is innovative, and it works together. It’s a cohesive, well-articulated concept that carries all the way through.”