As cofounder of a San Francisco–based executive search firm, Carrie Niederer has a system for finding the right person for a job. When architect Cass Smith first met with her in 2003 to discuss renovating her house in Sonoma, California, she showed him an article she had clipped from a newspaper years ago about a home he designed, which she saved for just this moment. Niederer not only got the aesthetic she wanted, but also a champion for her best interests.

The 1950s ranch-style house she lived in was unremarkable. It sat near the fenced edge of its lot, part of a former walnut orchard. “It didn’t take advantage of the whole indoor-outdoor lifestyle—the house faced the driveway, not the orchard,” Smith explains. He slowly campaigned Niederer to plant a new, tailor-made building in the middle of her two-and-a-half acres.

About a year later, Niederer acquiesced—but her sky had limits. Specifically, she puzzled over how to afford a $400,000 budget. Smith’s creativity didn’t stop at the drawing board, and he suggested renting out the cavernous outbuilding Niederer’s former husband once used as a studio. Soon afterward, the studio became a storage unit. Besides allowing her to use her land more densely, the additional income allowed her to pay for a new house.

“I believe in luxury through restraint, and through building what you need rather than building more than what you need,” Smith says. Even so, Niederer’s budget wouldn’t buy much in California. “I said, ‘You’re going to get a great house but it’s going to be really simple. There will be great connections to the land, nice high ceilings, good spaces and proportions, but not lots of bathrooms or fancy finishes.’”

Niederer says the duo viewed the price tag as a mission rather than a hurdle: “The goal was to prove we could build something that was really special and elegant, and cost effective. I think Cass was even more charged about it than I was.”

The most affordable form to construct was a 100-foot-long and 20-foot-wide box, with an exterior of cedar slats that aged to a purplish gray. As is typical for sustainable design in the region, the long axis of the house is oriented east-west to minimize the area of the house that’s exposed to direct sunlight. Outdoor curtains (hung on the house’s exterior) are in the works, Niederer says, which promise to cut exposure even more.

Because the house didn’t have huge expanses of glass, it could be built entirely of structural insulated panels (SIPs). The panels are comprised of insulation sandwiched between two sheets of a material called oriented strand board, or OSB: a plywoodlike product that’s made of wood strips bound together with resin. (Nearly all the wood from harvested trees is used when manufacturing OSB, unlike some other wood products used in construction.) The SIPs were custom-made and shipped from Grass Valley, about two hours northeast of Sonoma. The building method eliminated expensive waste, not to mention costly labor: It was assembled in just four days.

Still, a box is a box. “Cass kept referring to my house as a trailer,” Niederer laughs. While Smith admits he thought the house was a little boring, worse is that it lacked shade. “When you create a box, it doesn’t have any overhangs,” he says. “It’s a pretty harsh building to live outside of. In northern California you want to be outside, but you have to be in the shade.”