The Marfa Ranch house takes a fresh approach to a traditional way of building.
Architect Lake|Flato Architects
Contractor Pilgrim Building Company
Landscape Architect Ten Eyck Landscape Architects
Rammed Earth Enabler Austin
Mechanical Engineers MJ Structures; Positive Energy
Building Envelope Positive Energy
At the end of a dusty gravel road just off U.S Route 90, the Marfa Ranch rises on the horizon, a barely perceptible extrusion of the landscape. Blink, and you could miss it. Much like the West Texas landscape it inhabits, the project is a manifestation of paradoxes and extremes. Meticulous and coarse. Elegant and rustic. With just over 5,000 feet of conditioned space, the stabilized rammed earth home is ample without being ostentatious, crouching humbly in deference to the surrounding Chihuahuan Desert and Davis Mountains.
Rammed earth construction isn’t for the faint of heart. It is a physically demanding and time-consuming process. Couple that with the challenges of building in a remote, windy desert landscape, and it can become downright daunting. “As soon as they pick up a shovel of dirt, it’s halfway across the county,” says Bob Harris, FAIA, a partner at Lake|Flato Architects and designer/partner-in-charge on the project. “It’s a different environment. It’s something you have to be ready for.” The project began nearly a decade ago under a previous owner who, after the foundation was poured and two rammed earth walls were erected, decided to sell the land and move to a home within Marfa proper. A couple who met in San Antonio and already owned a ranch in Santa Fe, New Mexico, purchased the property and opted to carry through with Lake|Flato’s original design. (The plans were left unchanged, other than the transformation of a Jack-and-Jill suite into two separate guest suites.)
In the vast and sparse landscape that characterizes West Texas, traditional siting cues — as well as a reassuring sense of enclosure — that topography and fauna typically provide are largely absent. In fact, the pervasive exposed feeling can be unnerving for those who have not adapted to features of the open desert grassland. That meant that instilling a strong sense of shelter became a driving force in the project. To orient the building, the design team led by project manager Jennifer Young, AIA (an associate at Lake|Flato at the time), made use of the only existing structure on site — an old steel stock tank — along with views to nearby natural landmarks that had been used for wayfinding for centuries. The team also drew from spatial typologies found in traditional West Texas ranch homes and Mexican haciendas. “The traditional hacienda was there, at least in part, for security and protection,” says Harris. “Here, security is not so much an issue as is protection from the elements: the wind and the sun, the livestock, the rattlesnakes — all those things from the environment that find a way into your space. We found that creating a quality of space that feels contained and controlled increases the level of comfort.”
The home is composed of eight discrete structures oriented around a central courtyard with an outdoor walkway that extends into the landscape to connect to the pool and hot tub. A bench-height concrete wall surrounds much of the perimeter, providing a semi-permeable enclosure while hospitably inviting people to sit for a spell. The palette is minimal and elemental — earth, steel, and wood — and the structure clearly articulated, with massive earthen walls complemented by black steel detailing on window surrounds, interior fireplaces, and the bar. Corten sliding barn doors provide a fortress-like barrier from exterior elements, but once the doors are opened, boundaries quickly dissolve, in one instance giving way to a covered outdoor dining area with stairs leading to a rooftop deck.
The positioning of apertures and treatment of light, too, were major considerations in the project, not only framing views to the landscape, but also providing dramatic effect. The distinctive, brash desert light rakes across the rammed earth structures, highlighting its rigid geometries. In multiple instances, windows were installed at the crux of two walls, allowing light to graze the earthen surfaces, emphasizing the texture of the walls while also serving as a secondary source of illumination — a tactic that becomes critical for managing glare by creating a more even distribution of lighting. “The contrast between the light and the dark is so vivid because there is so much less particulate and moisture in the air,” says Harris. “The light is crisp and sharp — incisive — just like a laser. The shadow play on the surfaces becomes really important. Some of the windows just look onto a blank wall to show off the quality of light. At certain times of day, the shadow from the porch casts across that and cuts across the room. That play of light — you don’t get that if you just think of windows in a traditional way, or just as a means to play to views.”
Rammed earth is deceptively simple — a simplicity that requires near-perfect execution. Commonly used contemporary building methods have a series of inbuilt redundancies that hide flaws; with rammed earth, you have none of that. Says Harris: “It’s your structure. It’s your insulation. It’s your weatherproofing. It’s your wall finish. It’s the color of the home. Everything. You have to be really particular about getting it right the first time.” Accordingly, the home is meticulously crafted and obsessively detailed. Kyle Melgaard, a project manager with Austin-based Pilgrim Building Company at the time, notes that many of the construction details were already worked out by the architects in their 85-page drawing set. He says: “You only get one shot to get the rammed earth right, so we were extremely diligent in making sure everything was exactly right with the forms. There were definitely sleepless nights worrying whether windows were in the right place and if all the electrical was accounted for. That’s just a product of the level of project this was. The whole team was very proud to be a part of the project, and we wanted it to be as perfect as it could be.”
During the project’s first incarnation, there were attempts made to build with dirt quarried directly from the site. However, the high clay content made the structures prone to cracking; amending the soil would have been labor intensive and involved trucking in materials; and onsite excavation would have left a massive scar on the land. Additionally, the original rammed earth walls weathered excessively and were eventually demolished. The team started afresh, building two full-sized 8-ft-by-6-ft mock-up walls to test two different aggregates, one from Marble Falls and another from Van Horn. Ultimately, the latter was selected for its lighter tone, which also happened to be the greener alternative due to its closer proximity to the building site. To ensure consistency in the color of the aggregate, the team had enough dirt quarried and stored for the entire project, bringing in six to seven truckloads of dirt at a time. In the end, a whopping 76 truckloads, at 22 tons each, were brought into the site, totaling over three million pounds of earth.
To minimize weathering, the team opted to use stabilized rammed earth construction, starting with a 7 percent Portland cement mixture on the first structure and eventually landing on a 9 percent mixture that was used on the remaining buildings. Melgaard explains that the consistency of the mixture is key: The layman’s test is to clump a ball of the mixture in your hand and drop it. Ideally, it should hold its shape when falling and then break apart on impact, indicating proper moisture content.
“Rammed earth gets the bulk of its strength from compaction,” says Melgaard. “The Portland cement stabilizer adds to the wall’s strength and, in my opinion, longevity, but you do get a ton of strength due to just packing it into the formwork properly. Cement stabilization is a relatively new addition to the process, which has been around for thousands of years.”
The formwork was built for one structure at a time, with the material placed in the forms (every bit of the three million pounds was shoveled in by hand!) and tamped in multiple rounds, the formwork then disassembled and reconstructed for the next structure, and so on. Electrical was kept to a minimum inside the walls, which required a detailed layout for switching and knowing exactly where finished floor heights would be, then ensuring electrical chases weren’t damaged through tamping. Plumbing, on the other hand, was too high-stakes to install within the rammed earth walls; failure would have been catastrophic. Instead, it runs through interior walls, slabs, sleeves, and stem walls before exiting the building.
In the end, it took 14 months to complete the 950 linear feet of rammed earth walls that make up the ranch home — give or take a decade. And it was worth the wait. In a time when faster and cheaper is the pervading ethos — not just of building, but of everything — a good dose of “slow architecture” is just what the soul needs. A fleeting play of light. A moment for pause. Hands touching dirt.
Anastasia Calhoun, Assoc. AIA, NOMA, is the editor of Texas Architect.