Later this winter, a truck will pick up this prefabricated apartment from a former naval foundry in Brooklyn, carry it over the Manhattan Bridge, and deliver it to a construction site on Manhattan’s East Side. A crane will hoist the unit—and 54 others like it, along with segments of stairways and elevator shafts—into the air and stack them together, creating a nine-story building.

In a city that’s seen just about everything, the undertaking, a collaboration between the firm nArchitects, Monadnock Development, and the Actor’s Fund Housing Development Corporation, will be a novelty twice over. For one thing, this will be the tallest building ever constructed out of prefab modules in Manhattan, and one of the first such apartment buildings in the entire city. The modules—each of which weighs the equivalent of a dozen Ford F-150s—will arrive on East 27th Street virtually move-in ready, with toilets, cabinets, and electrical sockets all in place.

For another, this will be the city’s first “microunit” building. In 2013, its design won a city-sponsored “micro-housing” competition devoted to compact housing for single occupants. (Forty-six percent of Manhattan households are made up of one adult.) The architects, Eric Bunge and Mimi Hoang, hope that large windows, high ceilings, and floor plans featuring multipurpose living areas—fold-up furniture sold separately—will make the apartments feel more spacious than their 255 to 360 square feet.

Microunits and modular construction make a good match. “The whole point is efficiency through repetitive, assembly-line construction,” says Tobias Oriwol, the project developer for Monadnock. Walking along the assembly line as workers toil on two dozen apartments in various stages of completion, you see, as if in a flip-book, a finished home emerge from a cage of steel.

Bunge says that drafting a modular, microunit building is, in terms of complexity and precision, something like designing a car. The little boxes flirt with minimum-habitable-space laws as well as mandates regarding disability access, so there is absolutely no room for error. “If we were to … change drywall from half an inch to five-eighths,” he says, running his fingers across some plaster, “we’re screwed.”