If ever there was a design for a home that was informed almost exclusively by its setting, it’s the one architect Greg Faulkner devised for a wooded site in Northern California. The construction is a rigorously pared-down display of architectural elements that facilitate engagement with the natural environment. “This was a watershed project for the firm,” Faulkner says. “We were intensely focused on producing a quiet presence. The existing use patterns of the site and the path of the sun and the wind drove the design.”

The residence, located in Orinda, appears as a minimalist steel sculpture nestled at the base of a steep hillside cloaked in dark green foliage. “It’s in the wrinkle just before the Oakland hills at the foot of the Hayward fault,” Faulkner says. “Those big trees felt like refuge before we even built anything. They’re a free material that became part of the house.”

But before there was sculpture, there was a dated house on an unkempt lot.

“These rusting masses of steel change and refresh every time it rains, just like the landscape.” —Greg Faulkner, architect

Faulkner’s clients—a couple with two young sons—searched for the right property for a year and a half. “We lived in Oakland for seventeen years,” the husband says. “We wanted a bigger yard for the boys to explore.” When the couple discovered the site in Orinda, they were taken with the lot but not the existing home. “The house was ramshackle and the vegetation was overgrown,” the husband says. The wife adds, “It was not something we felt we could work with. But the land was beautiful. I knew it could be a place to build the house we’d always talked about.”

The home they’d always talked about was a sustainable and light-filled one with a modern presence. And when they saw Faulkner’s own home in nearby Lafayette, they knew he should be their architect. “His house also has steel as well as solar panels,” the husband says. The couple asked Faulkner to walk the site with them. “We climbed up to the roof of the old house and sat in the shade of a big oak tree,” Faulkner says. “It was a hot day and that tree was a place to gather. I repeated that idea for the new house.”

The architect began by situating the new residence under the shade of the tree, maintaining the footprint of the previous house. “This avoided additional grading and left the hillside open and natural,” Faulkner says. “And when I was sitting on the roof that day, I thought, ‘Wow, it’s great to be this close to the tree.’ It’s intimate because you can see every detail.” The architect found great inspiration in the oak, but also recalled the designs of Le Corbusier. “I thought of his mezzanine designs for the Unité d’habitation,” Faulkner says. “That’s how the master suite and the office were conceived. They’re part of a mezzanine level that connects to the hillside and is suspended within the two-story living space—they just kind of float.”

“You see the tree and smell the oak when you walk in the house.” —Greg Faulkner

Reynaers windows—expansive panes with thermally broken aluminum frames—evoke the feeling of being outdoors while also providing security and comfort. “These windows are the most solid I’ve seen in a residential setting,” the husband says. “They have a high rating for retaining heat and reflecting solar gain. They’re going to pay off in spades.”

Faulkner dressed the exterior of the house with Cor-Ten steel—another material that will pay off in spades since it’s relatively affordable and requires practically no maintenance. “For me, the materials aren’t optional,” the architect says. “They come from a feeling I get when I’m on the site. You really feel the changeable character of this landscape. These rusting masses of steel refresh every time it rains, just like the landscape.” The steel is a textural counterpoint to the unfinished white oak that Faulkner applied to the ceilings and some of the walls and floors. “You see the tree and smell the oak when you walk in,” he says. Basalt flooring and white gypsum walls in some areas help to break up the oak, making it more of a focal point.

But the landscape steals the spotlight at almost every turn, especially in the main living area, where a 12-foot-wide opening ties the space to the outdoors. “There’s a seasonal creek on the site and strong breezes flow down its path, so I opened the house with big pocket doors to the south and a private yard,” Faulkner says, adding, “My clients say that opening those doors cools the house instantly, so they don’t have to use the air conditioner very often.”

Faulkner also designed a rainwater collection system for the toilets, washing machine, and landscape irrigation. An 8.1kW photovoltaic system provides energy for the house, and ECM motors and variable-speed heat pumps limit energy use and control heating and cooling. “The mechanical and electrical systems were designed at 44.9 percent improvement over code,” Faulkner says.

In the end it’s a house that satisfies. “My husband and I both grew up where there was a lot of land, and we have careers that focus on the environment,” the wife says. “A house that brings the outdoors into our lives seemed critical.” It was a need Faulkner took to heart. “If you count glass as just space, we built this with four materials,” he says. “Any pretense is stripped away. Then, it’s just living.”

“Those big trees felt like refuge before we even built anything. They’re a free material that became part of the house.” —Greg Faulkner