Oliver Lang has always been something of a renegade. The German-born architect never settled into the idea of the high-rise condo nor of the conventional, detached single-family home—even after moving to Vancouver, a city that’s currently rich in both forms. Instead, Lang would rather look a few decades back to the innovators of mid-century design for guidance. “Modernism on the West Coast has always been about the relationship of architecture to landscape,” he says. Fifty years ago, that relationship took the form of post-and-beam single-family homes on treed lots—a rapidly vanishing option in a city like Vancouver, with its high land prices and need for densification. “If we still want to work within this paradigm, why not apply it to something more vertical, like stacked houses?”

Lang’s idea of a stacked house has led to Monad, a pilot project for what he and his life-and-work partner, Cindy Wilson, hope will become a widely adopted prefabrication design model. Monad comprises four separate residences—with over 12,000 square feet of living, commercial, parking, and storage space in total—each with an outdoor courtyard, a side yard, or a deck. The construction was handled by C.A.S.A., a local prefab company, and a site contractor to achieve highly precise finishes. The architects worked together to devise a modular system of posts, beams, and panels for the wood-framed, concrete-floored structure. The end result reads as a graceful and finely detailed complex of glass, steel, and concrete.

Lang and Wilson now hold forth—between gener-ous rounds of prosecco—atop their Vancouver home, surrounded by steel drums from which sprout herbs and other greenery. The vista is a centerfold of pitched rooftops and trees, with a distant silhouette of skyscrapers and mountain peaks. This open-air lounge—their own rooftop—is more expansive than a deck or garden, but it’s clearly not a conventional back- yard. Let’s call it a top yard, a large outdoor space that crowns the two-level family residence beneath it. Daughters Fiona and Olivia, 14 and 11, dart up to the top yard, gasp in joy at spotting the first humming-bird of the season, and then vanish back down into the house, one of a quartet of dwellings embedded within the four-story Rubik’s Cube of indoor-outdoor spaces.

Amazingly, the entire complex stands on a 33-foot-wide lot—the standard terrain of a single-family house. “We couldn’t have afforded to buy one of those over there,” says Lang, gesturing toward rows of century-old two-story craft houses; the structures, though charming in their way, are not a solution to the need for more housing within this growing city.

Monad is on the western stretch of busy Fourth Avenue, and life in the fast lane has proven beneficial. Few people choose to live along arterial routes like this one because they often offer little relief from the urban din. Monad’s outdoor spaces and patios, however, are secreted away from the street, thanks to the structure’s height and considered design. The indoor-outdoor harmony of the building also speaks to the origins of the project’s name: Monad is a term used by philosopher Gottfried Leibniz in his 1714 book, The Monadology, to denote the theoretical primary unit of the universe. Lang likes the concept—to him, it suggests a sense of relativity.

Flexibility is another value for which Lang strove. “When we design, we try to find untapped potential,” he says. For example, storage for each home stands at the basement level, rather than in the units themselves. And when Lang and Wilson’s two children eventually grow up and move away, the couple will have the option of converting their 2,100-square-foot, three-bedroom, three-bathroom dwelling into two smaller units by adding an interior wall. They could then utilize the space as a guest suite, a mortgage helper, or as multigenerational cohousing.

The cool, hard palette of the 2011 building is now softened by the young clematis vines that are just starting to wind their way up a series of steel cables extending from the ground-floor courtyard to the upper-floor breezeways. The industrial facade is further enlivened by a ground-floor neighbor’s artful, phosphorus-green patio furniture. And within this space-sharing microcommunity, residents some- times drop in to “borrow” an adjacent courtyard.

Most important though, Monad offers a different vision of urban housing—a flexible design and prefab paradigm generally championed by neither city planners nor condo builders. As Lang puts it, “The people will always be 20 years ahead of the planning.”