Bruce Falck long dreamed of following the example set by his father, who ran a construction company in Johannesburg, South Africa: He wanted to build a house designed specifically for his family.

“My dad was a civil engineer, and he built both of the houses I grew up in,” said Mr. Falck, 52, a former Twitter executive now working on a start-up. “I always thought of building a house as something a dad does for his family.”

In 2011, he came close. Mr. Falck and his wife, Lauren Weitzman, now 41, who works at Google, bought a house in San Francisco, hiring the architecture firm Studio Vara to do a gut renovation. But just as construction was about to begin in 2013, the couple had a change of heart.

“Kids were imminent,” Mr. Falck said, and the prospect of living in limbo during a multiyear construction project no longer seemed that feasible, especially to Ms. Weitzman. (They now have three children between the ages of 4 and 8.) Instead, they decided to sell the house and buy something that was move-in ready.

“Bruce was really bummed,” said Christopher Roach, a partner at Studio Vara. “But he said, ‘I promise you, in a few years we’re going to look for some land up in wine country, and we’re going to do a project together.’”

About five years later, in 2018, Mr. Roach received a two-word text message from Mr. Falck: “It’s time.”

With their architect’s help, the couple began searching for a lot in Healdsburg, Calif., in Sonoma County, and found a 15-acre hilltop site with views in all directions. “It felt like the African bush,” said Mr. Falck. The couple bought the lot for about $1.5 million in July 2018, before they had even fully explored the land.

Just before closing, Mr. Roach camped on the site overnight to study the property further, thinking about where best to situate a house. “I like to see where the sun rises and sets,” he said, “and where the breezes come from in the morning versus the afternoon.”

As the architect walked the lot, he realized it was even better than he had initially thought.

“One side of the hill goes down to a seasonal creek with big redwoods,” he said, while the other side is populated with oak and pine trees. “I took a bunch of pictures, recorded thoughts and did some initial sketches. And one of the first sketches I did ended up being the basic plan and layout of the building.”

The sketch called for a boomerang-shaped house at the top of the lot, backing up to the edge of a steep drop. The design soon evolved into a 6,200-square-foot house with 4,000 square feet of indoor space, largely enclosed by glass, under a broad roof covering another 2,200 square feet of outdoor space. The effect, when the glass doors are fully open, is that of a luxurious lean-to.

“It frequently gets blazing hot up there,” Mr. Falck said. “But the house is basically a giant shade structure.”

That concept also appealed to Ms. Weitzman. “When I was younger, I used to love the idea of the old Southern-style wraparound porch,” she said. “We got the modern version of that.”

The two halves of the boomerang contain two wings connected by a contemporary take on a breezeway, which can be opened and closed with pivoting and folding glass doors. One wing holds the bedrooms and points toward Mount Saint Helena and the sunrise; the other, which holds the kitchen and the dining and living rooms, faces the sunset.

The roof extends beyond the indoor living room to cover an outdoor room with a brise soleil, which connects to other outdoor spaces, including the pool deck and an outdoor kitchen and dining area.

The home is designed to be fire resistant, with standing-seam zinc cladding and walking paths around the perimeter that serve as firebreaks. It is also self-sufficient during power outages thanks to solar panels connected to a battery backup, and has its own well and septic system. Because of delays caused by Covid and wildfires, it took Fairweather Associates about two and a half years to build the house, at a cost of roughly $1,250 a square foot. The project was complete in June 2022.

“We watch the sunset, we’re in the pool, we’re in the hot tub, and Bruce is always grilling,” Ms. Weitzman said.

It’s exactly the kind of once-in-a-lifetime home Mr. Falck had in mind.

“This is a long-term thing,” he said. “For me, success would be having our kids, when they’re in their 80s, having a glass of wine on that patio and watching their grandkids swimming the pool. That’s the metric for success.”

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