In Montara, California, architect Michael Maltzan designed a home for, his sister and brother-in-law. From certain vantage points, the home’s unique angles result in M.C. Escher–like optical illusions. For Thomas Meyerhoffer, a product designer and avid surfer, and his wife Mary Kate, a graphic designer and serious rock climber, living in San Francisco was never about being in San Francisco. “It’s one of the few places in the world you can live in a big city and be so close to nature,” explains Thomas, who initially came to the Bay Area in 1993 from Sweden to work for Ideo. Nine years ago, the adventurous couple took the leap of leaving city life behind entirely, and bought a 30-by-30-foot cinder-block house in Montara, a small, sleepy seaside town just 25 minutes south of the city on Highway 1. Now nature was right outside their front door.

The new homeowners’ first decision was to gut the house completely to create an open plan. “It was just one big room where we did everything,” recalls Thomas. “We could just take down walls or put up walls; it was really experimental.” “We called it our bunker on the beach,” adds Mary Kate with a hint of sarcasm. Although renovation was in the cards, with other interests and pursuits occupying much of the couple’s time, the one-room bunker remained home for another six years. But with the arrival of their son, Dylan, it became clear that it was time to bite the renovation bullet. The couple didn’t have to look far to find an architect. They turned to Mary Kate’s brother, Michael Maltzan—a one-time protégé of Frank Gehry’s office who has experienced marked success with his own practice and commissions that include the MoMA QNS, a renovation of UCLA’s Hammer Museum, and the Fresno Metropolitan Museum.

“Because it was her brother, we were careful to engage in the right way,” concedes Thomas, acknowledging the shift the home represents from the architect’s usual roster of high-profile projects. Maltzan adds, “It is different than a lot of the projects we are involved in—at some levels—but I think an approach to architecture is an approach to architecture.”

To that end, the home is a one-off descendent of Frank Lloyd Wright’s Usonian house program: affordable designs from a big-name architect. Although getting the house built would take three years and as many contractors, Maltzan, Thomas, and Mary Kate achieved what is all too often out of reach: an architect-designed modern home on a budget.

“Everything is really basically done,” says Thomas of the construction. “Michael wanted to give us a shell, not something that was really refined or detail oriented.” The simple shell Maltzan designed utilized the existing foundation, going so far as to re-create a multipurpose main room over the original footprint, and even employ the same concrete cinder block throughout (which the architect also claims helped its permit status as a renovation). “There was a lot about the old place that we liked,” says Thomas. “There was no reason for not doing those things in the new house.”

“I think the design responds to two things,” counters Maltzan, “the way Mary Kate and Thomas live, and the bigger, more general aspects of the context—where the ocean is, where the views are, and how tight the site is. I think especially the way that they live and the site are so intertwined that those two issues of context and lifestyle are in some ways the same.” Because the couple travels frequently—Thomas visits his international clients, and Mary Kate makes the four-hour trek to the mountains for rock climbing—they wanted a house that was as small as possible and as easy to maintain as possible. Because friends often drop by while motoring down Highway 1, they also needed a large enough space to accommodate their social life. “There were over a hundred people here at our midsummer party,” Thomas says proudly.

On the ground level, the architect added a wing of compact bedrooms and tucked a studio for Mary Kate quietly at the back of the site. A new upper floor consists of a master bedroom and bath, two large decks, and what the couple refer to as their “quiet” room: a tidy glass box of a living area outfitted with daybed and fireplace—the perfect place to read while keeping an eye on the surf. “Or a good place to have guests when you haven’t cleaned up the kitchen,” adds Mary Kate. Housing Thomas’s substantial collection of surfboards and his vintage Cobra roadster, a detached garage with adjacent guest room rounds off the plan.

Another important consideration in designing the home was the unpredictable coastal weather. “When it’s cold and foggy out, it’s warm and cozy inside,” explains Thomas. “And then when the sun comes out it switches very quickly and you can just roll open the doors.” As most Bay Area residents (but perhaps not most tourists) are aware, blowing fog chills to the bone. Thomas clarifies: “It’s not like one of those San Diego outdoor living situations; once the fog comes in, we have to protect ourselves.” Part of this protection plan includes radiant heating and multiple fireplaces (there are three). “One of the first things you notice about houses around here is that they are really damp,” Mary Kate remarks. “But here it’s always comfortable, and we don’t even have to have the heat cranked.”

Although Maltzan’s spirited design proved to be a challenge for the local contractors—a line from Thomas says it all: “When I told them they had to come and take off the roof the second time, it was kind of hard for the contractor to take”—the home is true to their budget, lifestyle, and aesthetic. It continues to be a work in progress as the couple focuses on launching their own brand of surfboards. With the upstairs bathroom as yet untiled and the leftover IKEA kitchen from the old bunker still in place, Thomas surmises, “Maybe we’ll do that when it gets cold again. But why even bother? I like it.”