We Built Our Texas Home Out of Sand and Straw—and We Rarely Need Air Conditioning

For most of her adult life, Arielle Crawford focused on sustainability and holistic living. 

She taught sustainable manufacturing at the Fashion Institute of Technology in New York City, and made sure to eat organic foods and wear natural, breathable fibers whenever possible.

Still, didn’t give much thought to the apartment she lived in—until the COVID-19 pandemic hit. 

“I saw the walls and thought, ‘I don’t know what any of these are made of. It was a real aha moment,” she says.

That led her down a rabbit hole researching more natural construction. She left New York and moved to Texas, starting over in an off-grid environment. There, she met her now-husband, Simon Gonzalez, 43.

Until 2013, Gonzalez worked in typical construction. A lull in his schedule led him to take a job building  what’s now referred to as a “cob house”—and everything changed from there.

A new approach to homebuilding

During the build process, Gonzalez discovered just how toxic some of the most common construction materials can be. 

Materials such as “Tyvex, spray foam, plastic paint and moldy two-by-fours” are safe after installation, he says, but they’re off-gassing while exposed during the construction process. Worse, cutting these materials releases their particulates into the air, he explains.

The more he learned about the toxicity of typical construction, the more secure he felt in knowing he couldn’t return to it. That’s what led him to pivot and work only in natural building–and that’s how he met Crawford in 2023.

Together they formed Texas Cob, dedicated to natural building. They design, construct and restore using building methods that use traditional, nontoxic materials, such as adobe, lime plaster, limewash, and cob, which is a mix of clay, sand, straw, and water used to construct homes and other buildings.

They built about 10 houses before deciding it was time to create one of their own.

Building a home of sand and straw

The question of where to put down roots was answered when Gonzalez’s grandfather passed, leaving behind 5 acres in Kingsbury, TX, located an hour from Austin and San Antonio. 

Of the seven grandchildren, only Gonzalez expressed interest in the site, which had been a local dumping grounds for the last 30 years. The couple was given the land at no cost, but had to invest $60,000 to remove all the garbage covering “every inch.”

The other benefit: the land was unincorporated, outside of city limits. There were no building restrictions. 

Permitting can be the biggest hurdle, but in their case, it was made easier in a city like Austin where International Residential Code—the governing set of rules applying to all construction—already includes an earthen appendix detailing a clear prescriptive path. 

In places that have not yet adopted the earthen index, cob is treated as an alternative material, meaning that each homebuilder must prove it is safe. That homebuilder would need an engineer to sign off on the safety of the home plans, and given how niche these homes are, that’s a hard feat to accomplish. That would be especially challenging in a place like Florida as cob walls are weak in tension—the strength needed for support against hurricanes. 

The only permit that would have been required was for the septic, which they bypassed by relying on compost toilets and an above-ground system.

Building the 500-square foot-home took a year. They work full time with Texas Cob, leaving only weekends to focus on their own project. 

Crawford points out that “you can’t throw up a house like this in a couple months with two-by-fours and a nail gun. The cob goes up pretty quick, but the lime plaster takes time.”  

Inside a cool humble abode

The walls of Crawford’s home are 2 feet thick, which required a laborious process—but the end result offers unbeatable energy efficiency. 

Outside of summer, the nights cool off enough in this part of Texas that the couple doesn’t need to run heating or AC to regulate the interior temps—the structure is able to do that. (The home does have AC, though, as well as full electrical and plumbing just like any regular home.)

The home cost $160,000 to build. Of that, 70% of the costs were labor, and only 30% were materials—a breakdown typical to this kind of construction. 

The biggest expenses were the roof, electrical, plumbing, doors, and windows. Materials, such as the sand needed to assemble the cob, cost very little. The biggest expenses were trucking it in, then using heavy machinery to sift the sand into a finer, more uniform consistency.

When finished, a cob home looks and functions like any typical home—there’s AC, power, and running water. These are considered normal builds, so much so that they can be insured, but Crawford and Gonzalez have opted not to insure theirs.

“There is a lot of misconception” surrounding natural builds. “People think they’re going to look like hobbit houses,” says Crawford.

Far from it. The interior can be anything the homeowner needs it to be—the only difference is that the exterior is earthen. These types of homes “are part of the vernacular” in places like Santa Fe, NM, where adobe is incredibly common.

For their interior, Crawford and Gonzalez chose to keep everything round. 

“We don’t have any right angles,” she says.

Their home features fluted ceilings and even the bedroom is round, with a half-moon mattress, which Crawford made by hand. The result is “very calming for the nervous system.” 

“People have walked in here and started weeping,” she says of the visceral experience of the space.

“Everybody wants one after seeing it,” she says.

That's why, twice a year, the couple offers cob-building courses through their nonprofit, The Realness Preserve. 

Crawford also recognizes that building a cob home may feel like too big of a change for most people. 

“That’s where lime plaster comes in—that can be the solution for almost everybody” who wants to live in a nontoxic home. It’s a simple finish for walls, mixed from lime, sand, and water. It's also breathable and prevents mold growth. 

“It’s used all over the world, from Morocco to the old villas in Italy,” she says.

If lime plaster isn’t an option, there’s lime wash, which is an alternative to interior paints. 

All of these may feel new to modern populations, but humans have been building mud houses for at least 10,000 years. Which is part of what colors someone’s experience when they enter an earthen home. 

“There is definitely something nostalgic about it," says Crawford. “It feels like a homecoming.”