After a bumpy ride out of Montreal on Air CanadaJazz—a fleet of tiny planes with a service schedule as capricious and unpredictable as a Coltrane solo— we touch down on the windswept and largely treeless Havre-Aux-Maisons, one of Canada’s six interconnected Magdalen Islands. This little archipelago of red crags and endless dunes in the Gulf of St. Lawrence has a small year-round community, but has become quite the summer destination for Quebecers, like a rugged, Francophone Cape Cod but with fewer miniature-golf courses. Dirt (and often sand) roads are common, a local delicacy is harp seal (a fatty, fishy red meat that’s better than you might expect), fences only serve to pen in the few tranquil cattle, and the rolling green hills and lush meadows are sparsely dotted with humble farmhouses.

Unassuming and architecturally uniform though they may be, the magenta, canary yellow and even black houses provide the Magdalen Islands’ residential character. Local lore suggests that the sometimes outlandishly colored houses were born of maritime necessity. Fishermen painted them the same colors as their boats, and used their homes as reference points when sailing. Though navigation techniques are markedly more sophisticated today, the lively paint jobs have hardly run aground.

The eye-catching blue of the modest 1,690-square-foot vacation home owned by Montrealers Yves Bériault and Diane Decoste (a native Magdalen Islander) is very much of a piece with the rest of Havre-Aux-Maisons’ vibrant residences. “We wanted something lively for the house, something spectacular but not vulgar, so we looked at yellows and reds,” says Bériault. “I was a bit more conservative color-wise, but Diane and Marie-Claude took over, and I know now that they were right.” Decoste and architect Marie-Claude Hamelin, of Montreal firm YH2, settled on a cerulean blue inspired by the sea, the sky, and, as Hamelin puts it, “a child’s chalk. The architecture on the islands is rather naive, so we wanted to evoke that childlike quality in the color.”

When the house was first built in 1915, it was put to use as a one-room schoolhouse. But by the time Bériault and Decoste bought it from a friend and neighbor it was yellow, metal-clad, and hardly representative of the local architecture. “We didn’t know how nice the original structure was until we started to renovate,” says Hamelin. Tearing out what proved to be a false ceiling revealed a high, arched open space that the architects were desperate to keep. The bones of the building required little work—the architects even managed to keep the pine interior, whitewashing it to better set off the residents’ art collection—and by 2003 Bériault and Decoste had a wonderfully open living room and kitchen space with a small suspended office and a vaulted ceiling soaring some 35 feet above.

Restoring the house to its original form was something of a coup, but it’s what YH2 did behind the house that’s so impressive. Houses on the Magdalen Islands are often square affairs, with smaller outbuildings situated just behind. “In the old houses you’d have the main house and then about 20 feet away a small duplicate,” says Bériault. “It was used as a storehouse to dry fish or keep cranberries.” These tiny replicas still abound, though now they more likely house lawn mowers or tandem kayaks.

Hamelin and YH2 partner Loukas Yiacouvakis reimagined the traditional storehouse as a cozy domestic space rather than the destination of freezing, midwinter dashes for more salted cod. As theybuilt the storehouse-inspired structure they increased the usual size to accommodate a master bedroom with a bathroom below. The spacious bathroom with a roomy tub opens onto a sitting area littered with books and magazines, a literary antechamber to a nice long soak. The view from the sliding glass door, a private entrance to the second house, looks out onto green pastures, a verdant hillock, and a small canal through which boats pass as they head out to sea. This intimate space is linked to the main house by a richly hued, almost orange, cedar corridor that looks like an errant boxcar that has come to rest at an oblique angle between the two structures. Doors at either end of the corridor offer privacy to each end of the house. “We wanted to do two houses like you see all over the Magdalen Islands,” Hamelin says. “Instead of the storehouse idea, we took our inspiration for the second house from those small beach cabanas used for changing. We want Yves and Diane to feel as though they’ve just come from the beach to this small, intimate space.” Cedar was a clear choice, not only for its contrast to the blue of the exterior, but because Hamelin and Yiacouvakis wanted to work with a natural material that would lend itself to the island’s aesthetic. “I wanted to walk into the house and actually smell the architecture.”

The second house and cedar corridor dealt deftly with the main house’s small footprint, but the biggest puzzler was the basement beneath—a shabby space half sunk below ground level that Bériault and Decoste transformed into a guest apartment with two small bedrooms, an undersized common room, and a petite kitchen. “It’s just a little something for guests with pretty, simple Ikea decor,” says Bériault, but he proudly points out the living room’s massive chalkboard, a nod to the building’s original function. “Once you understand these islands,” says Bériault of the couple’s admiration for the local vernacular, “you realize that you can’t just pick up an architecture magazine and find some crazy thing you like and say, ‘I want that.’ There’s a certain naiveté, almost a childlike quality, about the architecture here, which we love, and we have to respect that.”