You can’t talk with Jim Murphy and Jay True for long before the conversation turns toward grapes. In California’s Sonoma Valley, where their company, Jim Murphy & Associates (JMA), is based, vineyards are everywhere. Doctors, tech industry entrepreneurs, and entertainment executives move here to establish their own labels. Well-off retirees grow grapes instead of grass. In upscale homes, climate-controlled cellars and tasting rooms are as common as ice makers. The influence shows also in the architecture of JMA houses: a robust Mediterranean blend with California farmhouse overtones and notes of San Francisco modernism. Building at the top of this market entails complex projects, sensitive sites, formidable regulations, exacting architects, and demanding clients. And in this environment, no one builds a better house or runs a better company than Jim Murphy and Jay True.

But don’t take our word for it. Ask JMA client Darryl Roberson. Roberson is founding principal at STUDIOS Architecture, an international firm whose recent projects include a 28,550-square-foot expansion of MTV Networks headquarters in New York and a 5 million-square-foot renovation of the Pentagon. Fifteen years ago, JMA built a weekend house for Roberson and his wife on a mountainside near the town of Sonoma. “It was sort of an experiment,” says Roberson, who produced only a minimal plan set and worked out details with his builder during construction. “What I learned from working with Jim and Jay was that they were right on it. They came up with a lot of great ideas.” When the time came to build a year-round residence on the property (see photos), he says, “It was automatic that I would work with them again.”

JMA president Murphy took a hands-on role in the project, Roberson says. “He knew I would be detailing it out as we went along, so I just stayed ahead of him. He knew I was the architect, but he also knew when he would step in with advice.” At least once, in the case of a stainless steel exterior stair, the builder actually overruled the architect. “Jim said, ‘What you have detailed isn’t good enough; I don’t think it will last over time,’” Roberson remembers. “And it was built already. Jim said, ‘We’re going to pull it out and do it over,’—at his own cost.” Roberson insisted on splitting the expense, but he remains impressed with Murphy’s insistence on getting things right. Moreover, he says, “He understood the design intent. My specifications were thin, but I trusted Jim.”

Murphy, who clearly enjoyed the collaboration, puts it more succinctly: “I love to solve problems.” Tall, lean, and not yet gray at 68, Murphy is famously frugal with words, especially when talking about himself. But an affinity for solving problems explains as well as anything else how a self-educated builder finds himself on equal footing with an architect of Roberson’s stature. Murphy got into construction in 1963, at the age of 21, as a drywall taper making $4 an hour, a career choice motivated primarily by the fact that his previous job paid only $3. But he seems to have shown aptitude for the work from his first day. “The next day,” he remembers, “they gave me a $1 raise.” By 1966, he was running his own drywall company, and was soon building houses on the side. He sold the drywall company in 1972 to concentrate on spec construction, but the early 1980s recession put an end to that. “It almost put me under,” remembers Murphy, who vowed never again to build with his own money. And so a custom builder was born.