In a city known for its strip malls and “acre-an-hour” developments of swiftly erected spec homes, Sarah and Ethan Wessel have devoted their careers to championing carefully thought-out, custom architecture. To illustrate their position, the couple spent more than 10 years creating their own home, using it as a test site for new building techniques and as a model for their clients.
Situated on a wide street in a dusty suburban neighborhood, the newly built, 4,000-square-foot, four-bedroom, four-bath house initially doesn’t look that different from the other houses on the block, midcentury moderns with low-slung façades, dirt cactus gardens and carports. But a closer look reveals the exterior is neither wood nor stucco, but a thick, rough, gray concrete with horizontal ridges and fossil-like knotholes. The mostly flat roof widely overhangs the sides of the house as much as eight feet in some places.
Inside, the exposed-wood-beam ceilings are 10 feet tall in some places and floor-to-ceiling glass windows open with pocket doors to the outside. Interior walls are left unpainted, with just the white plaster on the surface, trowel marks visible. The floors are limestone and the furniture is modern, some of it classic pieces designed by Ludwig Mies van der Rohe and some of it designed by the couple. Out back is a patio with views of Camelback Mountain, an outdoor living room and a homemade skateboard park built by Mr. Wessel for his two sons, ages 7 and 11.
“It was really important to us when you drive down the street that it feel right,” said Ms. Wessel, 38, at home with her husband, Mr. Wessel, 39. The couple, founders of design and construction firm Tennen Studio, bought the house in 1998 for $225,000, mainly for the lot. They spent about $375 a square foot rebuilding it, only earlier this year finishing the 800-square-foot master-bedroom suite with a sunken tub and its own sitting room and a partially shaded outdoor patio. A four-bedroom, 2,600-square-foot house less than a quarter mile away is on the market for $650,000.
“So much architecture now is based on appearance—it’s an attempt to create an iconic image. Theirs isn’t like that at all. It’s more like background. It is slow architecture because it takes a while to let it all sink in,” said Max Underwood, a professor of architecture at Arizona State University. He added the Wessels’ house fits into a movement by architects to create designs that are understated, modern and attuned to the harsh desert climate, aiming for “deeper relationships” to the environment.
As they built their house, the couple used it as an in-progress model to show clients the effects of techniques that are hard to visualize. Their exterior walls are made of poured-in-place concrete, meaning molds are set up on site and concrete is poured around wood boards, allowing the walls to be thicker and thereby keep the house cooler during the day and warmer at night. “We’d point to something and say, ‘I like that. What is it? I want that,’ ” said Mike Sparaco, who owns a printing shop business in Tempe. He and his partner had the Wessels design and build a 4,900-square-foot house that he describes as “a bigger version of theirs.”
The Wessels met in 1991 at Arizona State University’s architecture school. She was from a small town in Washington state; he was from a small town in Connecticut. Neither thought they would ever stay in Arizona: Their plan was to hit New York. But Mr. Wessel graduated two years ahead of Ms. Wessel and he started a job with a contracting firm, waiting for her to finish.
Little by little, the couple started to love the sun, the light, the climate and the landscapes of Phoenix. In 2001 they founded Tennen, which designs and manages the construction of residential projects, including customized finishes, cabinetry and hardware, that range from $1 million to $20 million.
But there’s one thing that practically dominates the Wessels’ house that isn’t intended as a model for clients: a large, custom wood-and-glass cabinet off the main living room that holds several hundred squat, colorful vinyl rabbits. Called Dunny dolls, the $50 dolls were first spied by the Wessels at New York’s FAO Schwarz; since then the couple have become enthusiastic collectors, even attending local Dunny trading parties.
“We call them designer Dunny cabinets,” Mr. Wessel said.