For two months in spring and again in fall, Herbie Schlaepfer and Barbara Haeusermann lock up their house near Zurich, Switzerland, travel some 6,000 miles, and climb aboard their floating home in Sausalito, California, a picturesque town just north of San Francisco. Spread across five residential marinas on the Richardson Bay, its enclave of some 400 floating houses has its roots in the 1800s, when artists, shipbuilders, and other free-spirited types started moving into informally anchored arks. Although today’s dwellings occupy permanent berths and are connected to city services, walking through the marinas’ gates still feels like entering another world.

Amid the motley of architectural styles, from nautically inspired to shingled country cabin, the couple’s newly built, 2,894-square-foot home is like a palate cleanser for the eyes. One zinc cube cantilevers off the other, with great walls of glass that slide open and disappear.

“Many of these houses are perched right above the water, with no possibility to go down and touch it,” says Herbie. Adds Barbara, “We really wanted direct access to the outside, and also to our boat.” After making an offer on one house and having it rejected, the couple purchased a tear-down relic from the area’s Bohemian past—a pyramid-shaped structure supported atop several World War II–era buoys (one of which is now memorialized as a piece of art on the succulent-clad green roof). They consulted with a friend in Switzerland, architect Christof Glaus of Stücheli Architekten, who came for a visit before conjuring the concept for the stacking cubes.

“We really wanted direct access to the outside and to our boat.” Barbara Haeusermann, resident

“It’s actually a very clever approach to the site,” says Daniel Hunter, who as architect of record designed the interior and worked in tandem with Glaus to facilitate the design review, neighborhood approvals, and compatibility with local codes. “It gives them what most people residing here don’t have—a large living area above-deck, with ample outside space and plenty of privacy.”

The main level is a light-filled great room, with a sleek kitchen and living room that flow into the alfresco dining deck overlooking the water. One floor down is a guest room and a few steps away is the barge, the brains of the operation. The black water pumps and gray water tank are stashed here, as is an extra-large battery pack. Charged with excess energy produced by the solar panels, the pack keeps the lights on and fridge humming in the event of a power failure; anything left over goes back to the grid.

A glass-enclosed floating staircase connects the floors, while the master suite above juts off the supporting cube. That cantilever required a steel moment-resisting frame, which was built locally, as was the barge. Both were towed to the nearby town of Richmond, where the house was constructed, and once everything was assembled, Herbie rode back through the Raccoon Straits to Sausalito, waving from the deck of his new holiday home.

With San Francisco in one direction and the wine country in the other, this getaway seems an obvious magnet for guests. “Fortunately for us,” Herbie says, “it’s a twelve-hour flight from Switzerland.”