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Couple with no construction experience turned earth, straw, and water into their own home in the Bitterroot Valley, Montana, and started a business to teach bioconstruction after living mortgage-free in a cob house built manually over nearly three years.
Daniel and Katherine Ray live mortgage-free in a cob house they built themselves in the Bitterroot Valley, in Victor, Montana, USA.
With about 70 m², two bedrooms, and one bathroom, the home was featured by Business Insider in 2023 as the result of a manual construction done by a couple without professional training in architecture or civil construction.
Cob house in Montana became an alternative to renting
The construction was built with a mixture of earth with clay, sand, straw, and water, materials that replaced much of the conventional inputs used in residential buildings.
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According to Daniel’s estimate to Business Insider, the cost of the house was below US$ 20,000, a value that does not include the land where the property was built.
Before building the home in Victor, the two returned to Montana while still paying rent and looking for a more affordable alternative to owning a home.
The first experience took place on Daniel’s parents’ land, where the couple built a smaller house, about 28 m², before purchasing the larger property in the Bitterroot Valley.
In the spring of 2016, Daniel and Katherine began building the second house, a project that took nearly three years of work to complete.
After completing most of the construction, the couple moved into the property in the fall of 2019, shortly after the birth of their daughter.
Technique with clay, sand, and straw requires manual work
While still in college, Daniel and Katherine saw images of cob houses in Wales, a contact that sparked their interest in earth-built constructions.
From this initial reference, the couple began gathering study materials, consulting books, and seeking information online until they turned an old curiosity into a real housing project.
To Business Insider, Daniel reported that both graduated in anthropology and that he also has a master’s degree in library science and information science.
Even with academic training, neither had experience as a contractor before designing the plan, organizing construction phases, and directly participating in building their own house.
During the construction period, the routine required continuous effort because the couple maintained full-time jobs while progressing through the stages of the property.
Daniel stated that they also dedicated about 40 hours a week to the construction, in a manual process that depended on mixing, application, drying, and constant adjustments to the walls.
The cob used in the house is prepared with clay-rich soil, water, and straw, a mixture that gains consistency when worked with feet on tarps.
Instead of blocks joined by mortar, the technique allows molding the walls in successive layers, until forming a continuous structure with an organic appearance.
Natural materials shaped the curved house
A good part of the natural materials used by the Rays came from sources close to the property, according to the information provided by Daniel to Business Insider.
The straw applied to the walls was from the region itself, while the soil, the main component of the structure, came from a quarry located about five miles from the house.
With an organic shape, the construction deviates from the standard of straight walls, 90-degree corners, and rigid lines common in conventional properties.
Daniel explained to Business Insider that almost everything in the property is curved, including internal elements molded with soil, such as countertops, shelves, and support areas.
Even with a handcrafted appearance, the dwelling was not planned as an isolated shelter or without basic resources for the daily use of a family.
The property is connected to the electrical grid, uses well water on the property, and was organized to accommodate a common residential routine.
Low cost does not eliminate the limits of bioconstruction
The savings obtained in the project came from the combination of natural materials, execution done by the couple themselves, and gradual payment of the construction phases.
Since Daniel and Katherine funded the construction directly, they did not need to take on a mortgage to live in the house after moving in.
When comparing the project with conventional constructions in the same region, Daniel told Business Insider that new properties usually ranged between $150,000 and $200,000.
Despite the cost difference, the case itself shows that such a construction requires physical effort, available time, and willingness to learn during the process.
There are also practical limitations, as not every terrain, climate, or set of municipal rules allows for the same solution adopted by the couple in Montana.
The Rays reported that they chose the region also because there were fewer local requirements for codes and permits for this type of construction.
During the Montana winter, the house uses a rocket mass heater, a heating system mentioned in the report as one of the solutions adopted in the property.
Thick walls also contribute to thermal stability because they absorb and release heat slowly, according to the explanation given by Daniel to Business Insider.
Mortgage-free housing turned into a workshop business
After completing the house, Daniel and Katherine created SpiritWood Natural Building, an initiative aimed at teaching natural building techniques to others interested in the topic.
The company’s official page states that there are workshops open for registration in 2026, with courses on cob introduction, cob walls, natural plasters, and rocket mass heaters.
In addition to workshops, the business offers consulting and private construction of small structures in the Bitterroot Valley region, where the couple lives.
On the official site, SpiritWood claims to work with self-builders and other companies on projects made with healthy and locally sourced materials.
The Rays’ journey gained attention for combining mortgage-free housing, low-cost construction, and traditional technique in a context of expensive housing in the United States.
Even so, the example does not dispense with planning, local authorization, and technical evaluation before any attempt to build a similar house.
For Daniel, the main message of the workshops is to show that building a house can seem less inaccessible when the project is compact and the process advances in stages.
In the case of the Rays, this alternative required years of effort before turning into their own home and a source of income related to bioconstruction.
Would you trade a conventional construction for a handcrafted house made of clay, sand, and straw if it drastically reduced the cost of housing?
