Set on a winding street and screened by clusters of creosote bushes and palo verde and ironwood trees, Ethan Wessel and Sarah Swartz Wessel’s Phoenix residence does little to call attention to itself. And that suits them just fine. “We’ve come back from the airport and the driver will ask, ‘Where’s the house?’” Ethan says. But step through the gate, and the front courtyard opens to a breathtaking vista clear through the living/dining room to the rear patio and beyond to a custom skate bowl.

As evidenced by that last feature, the house is not just a family home for the designers and their sons—Addison, 17, and Elliot, 13—but a richly personal expression of what intrigues and delights them. Designed over the course of 10 years and still a work in progress, the house and garden have become a kind of canvas on which the pair explore, experiment, and even make mistakes. “It’s our testing ground,” Ethan explains.

Juxtaposed with limestone floors, wood-beamed ceilings, and walls of hand-troweled plaster and board-formed concrete, glass is strategically placed throughout the 4,000-square-foot expanse to frame slivers of landscape and sky or open wide to reveal gardens of various sizes, which the couple also designed. Rooms spill onto patios that become extensions of the house. “People think simply putting in a door or a window will connect the interior and exterior, but it’s more than that,” says Sarah.

“The tactile experience of our home is dependent on the changing desert light as it plays off the layers of textures inside and out." —Ethan Wessel, designer and resident

The home’s thick, textured walls are a modern nod to traditional adobe buildings; their mass ensures a cool respite from the scorching summer heat, while deep overhangs offer additional shade. “Poured-in-place concrete is a very appropriate material here,” Ethan notes. “And it blends into the desert palette.”

The couple met while attending Arizona State University’s architecture school. Though both hail from elsewhere—Sarah from Washington State and Ethan from Connecticut—they remained in Phoenix and launched the architecture firm Tennen Studio in 2001 and Tennen Construction a year later. “Tennen is a really old Japanese word meaning ‘existing in nature’ or ‘coming from nature,’ ” says Sarah. “That’s very significant to us. Nature is not just living things and plants. It’s that you let things happen naturally and embrace nature.”

For the Wessels, tennen is more than a design philosophy; it suffuses everything they do. Their fascination with Japanese culture and design sensibilities extends to the line of incense burners and Japanese incense they recently began producing.

After buying the property in 1998, the couple stripped down its undistinguished 1950s house and lived in it for about a year before making any major changes. They studied the light, built models, and talked about how they wanted to live. “We wanted a home for ourselves,” says Ethan, “but we also wanted to create something that would show what we could do.”

“We didn’t want something flashy or different. The house is the same height as the house that was here before and the pitch of the roof is the same." —Sarah Swartz Wessel, designer and resident

Tearing down the old house, save for one wall, they began with a footprint in the form of a lowercase “h,” its core containing an open living/dining space that extends to a study and a sitting area that overlooks the front courtyard. As their work evolved, so did the house, which grew, according to their master plan, to a capital “H” with the addition of a master bedroom wing. Along the way, they redid the kitchen and transformed the playroom into a music room and the family room into a tea room. “Nothing is set in stone,” Sarah explains.

The skate bowl, created by X Games veterans CA RampWorks and decorated by local graffiti artists, is a place where Ethan and the boys can carve and grind or just hang out with family and friends. “It’s also a fort for teenagers who no longer want a playhouse,” says Sarah. “They’ll take blankets and pillows and lie in the bottom and look at the stars.”

Organic vegetables flourish nearby, planted each season with help from the sustainable gardening consultants at Phoenix-based Farmyard. “My parents always had a garden,” Sarah says. “The idea that my kids never understood where their food came from tugged at me. The boys are very involved in it—they do the harvesting and bring the vegetables up to the house.”

Whether they’re augmenting their skatepark, planting a memory garden, or punching out a wall to open up a new vista, the Wessels find that designing for themselves teaches them that architecture isn’t static, and it’s a lesson they pass on to their clients.

“Sometimes we’ll do something and regret it, but not very often,” says Sarah. “We’re much better at making decisions that are really instinctual.”