This Minimalist, Solar-Powered Home Is a True Desert Oasis

This Minimalist, Solar-Powered Home Is a True Desert Oasis

By Lucy Wang
Designed to amplify connections with the desert, a low-lying courtyard house nestles into the landscape.

As a self-proclaimed architecture nerd, Dean Heckler spent years keeping tabs on innovative houses across Phoenix in anticipation of one day building his own custom-designed home. So, when he and his fiancée, Angela Joyce, were ready to leave the city for a quieter neighborhood, he turned to a pair of local architects who had long inspired him: Cavin and Claire Costello, the husband-and-wife duo behind The Ranch Mine.

"We could tell they truly felt their only concern was to create a home that is perfect for us," said Dean. "We could tell that working with The Ranch Mine would be fun—and it was."

The O-asis house is set on an elongated 1.7-acre site on a horse property area of Phoenix, north of Piestewa Peak within the Phoenix Mountain Preserve.

While Dean and Angela’s vision of a secluded, minimalist home intimately tied to the desert set the design direction, it was the needs of the couple’s two dogs that inspired the home’s enclosed central courtyard. The open-air courtyard not only provides ample outdoor space for the dogs to roam safe from desert predators, but also brings in indirect natural light and ventilation.

A textured flagstone path leads to the deliberately discreet front entrance, which blends into an ipe-clad niche.

The entry door opens up to direct views of the central courtyard. "This view replaces the traditional accent wall, or piece of artwork, with a glass opening framing the sky and exotic plants (with a 500-year-old ironwood tree focal point) drawing your eye through the courtyard, expanding the feeling of the space," note the architects. The black lighting fixture is from Restoration Hardware.

The central 18' by 58' courtyard also inspired the home’s name: O-asis. "Our O-asis house gets its name, and specifically the ‘-’ in it, because of its O-shaped plan," explain the architects. They say that the home serves as a refreshing escape not only from the desert heat, but also from the architectural trend of grandiose, 30-foot-tall homes.

Designed to disappear from the street, the single-story white stucco home is only 12.5 feet tall to avoid disrupting the neighbors’ views. "Its strong horizontal form was designed as a datum for highlighting the dramatic shapes of the desert landscape," note the architects.

"We designed the house to eschew the tired traditions of what defines a luxury home (size/height, glitz, glamour, high-price collections, etc.) in search of modern luxuries such as energy independence, low maintenance, seamless indoor/outdoor living, growing your own food, peace, tranquility, multigenerational living, and connection to nature."

The 15.12 kW Tesla solar array that tops the reflective white roof is hidden from view on the ground. The solar panels provide enough power for the home and cars for most of the year; Tesla Powerwall batteries store excess energy. Also pictured is a vegetable garden at the top right corner.

"The pool breaks from the O-shaped plan, drawing you out into the desert toward the mountain views to the south, and is capped by a built-in fire pit bench," say the architects.

The south-facing view from the kitchen looks out over the pool and mountains in the distance.

To enhance the home’s relationship to the desert, landscape architecture firm The Green Room transformed the site with earthworks to connect natural drainage areas and habitats while strategically screening the property for privacy. An elevated native Sonoran desert plant palette encourages biodiversity and seasonal interest. A key feature of the landscape design are the century-old ironwoods, which are rare hand-selected specimens salvaged from Phoenix’s urban sprawl.

Along with specimen Ironwoods, native Foothill Palo Verde were brought in to achieve a unique Sonoran desert character. 

"The streamlined forms of the pool and the house contrast with the dynamic shapes of the desert flora and boulder outcroppings, exaggerating their uniqueness," explain the architects. Multiple microclimates were created around the site to promote biodiversity.

"One of our main goals at O-asis was to envelope the house in the Sonoran Desert, so as not to interrupt the ecological processes on the site—and utilizing these large, native trees is critical to both the short- and long-term success of the landscape," explains landscape architect Matt Thomas.

An extremely rare stump Ironwood specimen with a gnarled growth habit serves as the centerpiece of the interior courtyard. "It’s used to create a metaphor that this new house was built within a native grove of Ironwoods," says Matt Thomas. The courtyard also helps passively cool the house.

The century-old gnarled Ironwoods contrast with the streamlined design of the smart home, where almost everything can be controlled wirelessly—including the clients’ beloved grand piano—making it a first of its kind in Arizona according to the architects.

"Playing the piano is a large part of their life, so we wanted to give it a great space to be played and to be heard," explain the architects. The piano area is located to one side of the open-plan living space.

Slatted walnut walls are located on either side of the main living area. "We found in many modern homes with open floor plans that there is a really poor sound quality," explain the architects. "We wanted to design a solution that was not only aesthetically pleasing, but solved this issue—so both sides of the main living space have wood slat walls backed with acoustic felt."

A close-up of the wood walls. Acoustic felt is set between the slats, which improve acoustics and hide doors and storage space. Here, the door pull to the master bedroom is hidden in the wall, which retracts like an accordion.

To further improve the acoustics of the open floor plan, a walnut-slatted, acoustic felt-backed dropped panel with integrated LEDs hangs above the kitchen island.

The home spans an area of just over 4,000 square feet, and includes an 860-square-foot in-law suite for the clients’ aging parents. Deep recessed patios, operable glazed walls, and an insulated high-performance building envelope with concrete floors help maintain comfortably cool temperatures year-round while minimizing the solar-powered home’s energy footprint.

To mitigate Arizona’s intense sun, the home does not have any west-facing windows. Instead, the architects installed niches for windows facing north and south on the west elevation to let in natural light.

The pool helps cool and humidify the air before it’s drawn into the home.

Pocketing glass doors on either side of the main living space can be completely opened for cross ventilation. The blue living room sofas are from Feathers Fine Custom Furnishings.

Described by the architects as the place where "spa meets retail," the master bathroom and closet revolve around two floating islands natural lit by skylight wells above.

Black walnut surrounds the U-shaped master closet.

A glimpse inside the limestone-clad steam shower in the master suite. The walnut slat walls hide storage with cubbies for towels.

A peek inside the master bedroom.

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An 860-square-foot in-law suite for the clients’ parents is located on the northeast side of the home.

The in-law suite shares two walls with the main house to save construction and operation costs, but is equipped with a separate entrance, a private patio, and a full kitchen, living area, ensuite bedroom, and laundry.

A shot of the in-law suite’s deeply recessed patio. Note the Cor-Ten steel slat fencing fitted with a rattlesnake guard.

The yoga room built for Claire’s mother, who is a yoga instructor, is one of the architects’ favorite areas in the home. The meditative retreat frames desert views through a long window, and is the only room in the home with cork flooring rather than concrete. Custom walnut cabinetry minimizes clutter.

O-asis house floor plan

O-asis house section

More from The Ranch Mine:

This Arizona Home Takes Design Cues From the Mighty Saguaro

A Desert Oasis Awaits in a Historic District of Phoenix

The Everyday Carry of an Architectural Duo: The Ranch Mine

Project Credits:

Architect of Record: The Ranch Mine / @theranchmineofficial

Builder/ General Contractor: Boxwell Homes

Structural Engineer: Broderick Engineering

Civil Engineer: G-matrix

Landscape Design Company: The Green Room

Interior Design: The Ranch Mine

Cabinetry Design/ Installation:  Baker Hesseldenz Studio

Other: Sequoia Trail Engineers


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