The best part of Persian rice is the crunchy crust from the bottom of the pot—the tadig—which, traditionally, you aren’t supposed to serve until the end of the meal. Eat it before and “you’re saying that, in effect, the meal is over, and there are no more goodies,” says Mahnaz Fashandi. “I had to tell my mom, ‘No, it’s OK to bring the tadig out with everything else.’” Negotiating the customs of their extended families is part of Mahnaz Fashandi and Jawed Umerani’s life: Fashandi, originally from Iran, has elderly parents who live with them about half the time and five siblings who pay occasional visits, while Jawed is from Pakistan and often sees his mother and three brothers. On both sides, there is a deep-rooted culture of enormous social gatherings.

At home in Los Altos, California, 45 minutes south of San Francisco, the contemporary and traditional worlds mingle together like yogurt and fizzy water—a Persian drink they serve often—in a refreshing update on the single-family home. Designed by Bohlin Cywinski Jackson, the firm best known for designing Apple’s impeccable retail temples, the Umerani residence embodies simplicity and transparency, facilitating togetherness without claustrophobia: a good recipe for extended family visits.

Umerani, who came to the United States from Karachi in the late 1970s to study structural engineering, has a long working relationship with BCJ. He served as structural engineer on several of the firm’s local projects beginning in 1997 with Pixar’s Emeryville headquarters, followed by the Apple store in San Francisco and other award-winning residential projects. These close collaborations led to friendship between Umerani and the BCJ architectural team. “I loved how there was no cookie-cutter or signature thing, no ‘This is how buildings should be’ in their approach,” says Umerani.

In 2005, Pennsylvania-based BCJ partner Peter Bohlin paid a visit to Apple headquarters in Cupertino, and Umerani invited him to his home. He wanted Bohlin to take a look at the old ranch house he and his family were ready to update after about a decade of living in it. Over tea, served in gilt Persian glasses accompanied by walnuts and dates, Umerani and Fashandi, a biochemist, talked to Peter about what they wanted for their new home.

One key idea they had was to create two living areas, so that large groups could disperse and find comfortable spots, whether for family gatherings, their college-age son Mehran’s friends, Umerani’s Urdu poetry reading group, or Fashandi’s friends. Fashandi and Umerani both wanted a water feature, since each grew up in a home with a fountain, a traditional architectural element in Islamic countries. “The sound of the water is very nice—I love the sense of serenity it adds,” says Fashandi. On his wish list, Umerani also wrote, “Exposed structure, elegantly expressed.”

Because the site is closely hemmed in by neighboring homes, the architects at BCJ proposed a courtyard house. “We were looking for a way to give all the rooms a special world, and the solution was to have them surround a court,” says Bohlin. “It’s a great surprise—you come in from the suburban world of 30 years ago outside and enter into this very calm space.”

From the outside, the one-story house plays it low-key—a modern structure, to be sure, but one that appears to be made almost entirely of wood with a pair of horizontal windows and one larger window peeking out onto the street. A modest screen of ipe slatting funnels you to the front door.

Once inside, visitors find themselves in a sublimely transparent space, looking through glass walls into the large courtyard. All the public spaces connect directly to this central yard, and the hallway leading to all the bedrooms runs along it as well, making everyone’s comings and goings visible. In warm weather, the family opens the courtyard’s many sliding doors, and the simple square fountain gurgling in the center adds a gentle counterpoint to conversations around the house. Guests converge in the kitchen and meander easily to the dining table and sofa, since all are in one large room. But they also have the choice of migrating over to the other sitting area to the left of the front door, a room where Umerani likes to spread out all his blueprints when he works from home.

“Because Jawed thinks a lot about how buildings are made and how they work, you couldn’t really ask for a better client,” says Gregory Mottola, one of two principals running BCJ’s San Francisco office. “The central courtyard idea kept on getting refined, and together, we figured out how to do it without any solid sheer walls.” The two side walls are reinforced by a giant X of slender tension rod braces, the most attractive lightweight solution, and the wall facing the entry is similarly braced. Douglas fir rafters and ceiling panels soar overhead. BCJ’s residential work often features galvanized steel framing with timber roofing, the contrast throwing each material’s beauty into relief. A row of steel columns in the great room provides support, but also hint at a classic colonnade. The architect and couple chose bolted connections, rather than welded ones, and decided to leave the nuts and bolts that hold the structure together exposed, providing the space with the satisfying sense of being in a massive Erector set. “All the things that Jawed does in his professional life on a daily basis, we’re celebrating in this house,” says Mottola, who oversaw the completion of the project in late 2008.

Fashandi, who had been eager ever since moving in to see something—anything—done to improve the dark, run-down house, has seen her greatest expectations fulfilled. “I didn’t know the house would be like this, because I didn’t have the capability to read blueprints, like Jawed,” she says. “I love it. When our guests come here, they don’t feel like they’re guests, which is great,” she says. “And when we have family staying with us, we can be together but apart at the same time. In the old house, it was like we were always running into each other.”

Celebrating Persian New Year in mid-March, Umerani and Fashandi have about 20 guests over including Fashandi’s brother in from Chicago. For the Los Altos family, this is a small gathering. “When the shoe racks in the closet are filled—they hold about 40 pairs—that’s a sign that we’re starting to max out,” laughs Umerani. But even when it’s just the two of them, the home still feels convivial. “I can sit in my chair by the fireplace and see straight through the courtyard to where Jawed is working in the TV room,” says Fashandi. “It’s nice to see people moving around, it brings a sense of life to the house.”