Saving as much water as possible when designing a desert house may seem like a no brainer, but numerous housing developments in arid cities in the Southwest still show off acres of lush landscaping requiring constant irrigation. Some houses there also feature expansive rooflines that absorb heat and dump what little rain the area gets into streets where the water becomes polluted and unusable. A spec house concept in Phoenix, however, makes a water-conserving dwelling in the desert a reality, not an afterthought.
In creating the prototype for the idea, architect Matthew Salenger and developer Austin Trautman looked to resilient desert plants for inspiration. "A Saguaro cactus uses its ribs to shade the adjacent valleys, while the needles spread out air flow," Trautman says. "If it didn't have those features it would dry out and die and we used that to create our siding."
To that end, the home's roof subtly slopes toward each side elevation where water is collected and then directed into twin swales running alongside the house, carrying all runoff into the backyard. Those same native plants inspiring the house's design are used to create an irrigation-free yard. In addition to not wasting any potable household water on landscaping, careful plant selection and layout reclaims and cleans 100% of rainwater that falls on site. After researching how desert foliage maximizes the scant precipitation received in Phoenix, the team placed specific plants closer to or farther from the structure based on hydration needs.
"When water first comes off the roof it hits plants that like a lot of irrigation—but not standing water—like cactus," Trautman says, adding that closer to the back of the yard where the water stays until it's absorbed into the ground, they chose trees that need water for more prolonged periods.
"Biomimicry talks about borrowing ideas from nature to give back to nature," Trautman explains about the philosophy of their firm, Vali Homes. "The way we landscape connects people to this amazing ecosystem."
While the site shines as a water-wise masterpiece, the Vali Homes team also made significant savings inside the house. When it comes to low-flow fixtures, Trautman insists on quality products that homeowners will enjoy rather than replace with higher-consumption models. For example, he says, new technology based on aeration and hole patterns can actually make a low-flow shower feel better than a traditional one. The team personally tested several showerheads before picking one that felt great and worked efficiently. The winner? Bricor's Elite-R showerhead, which has a 1.5-gallon-per-minute flow—compared with 2.5 gpm, the rate for most low-flow fixtures.
The duo's holistic approach to water conservation is working: The prototype house weathered an extreme situation recently and the landscaping performed better than expected. "We designed the site to retain all water from a 100-year flood," Trautman explains, "but last September we had more than 4 inches of rain in a single day, which nearly doubled the 100-year flood amount, and the site didn't release any water."