• Cal Earth building

The SuperAdobe: Sandbags & Sustainable Living

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Everyone needs a roof over their head. This is what motivated architect Nader Khalili to establish the California Institute of Earth Architecture (CalEarth) and design the SuperAdobe, a domed sandbag structure that has the potential to solve the global housing shortage through sustainable design.

Words by Aaron Chapman

Although adobe has come to broadly denote a distinct architectural style characterised by soft and curved forms, adobe construction is best characterised by its materials: mud, earth and organic matter compacted into bricks. The California Institute of Earth Architecture (CalEarth) is a not-for-profit whose mission is to address the global housing crisis. They do this through the construction of adobe homes that are both energy-efficient and materially composed of earth sourced from its respective region.

In CalEarth’s words, “we strive to honour our late founder (and architect) Nader Khalili’s vision of an architecture based on the natural elements of earth, water, air, and fire, and their unity at the service of humanity and to continue his mission to provide shelter for the world’s homeless and displaced persons, empower people to participate in the creation of their own homes and communities, and help preserve the planet that we all share.”

Junoot Eco Dome Exterior

“The SuperAdobe is a unique construction of long sandbags filled with moistened earth, coiled on top of each other to reach its eventual domed shape, synonymous with adobe architecture.”

A recent study indicated that “about 1.6 billion (more than 20 percent of the world’s population) may lack adequate housing.” This is a frightening statistic. Everyone needs shelter. It’s a fundamental human need. Yet the global housing shortage is being exacerbated by environmental challenges, which are expected to compound in the future. To address these issues, Khalili opened CalEarth in 1991, conceived the SuperAdobe and aimed to spread its message of sustainable housing. 

The SuperAdobe is a unique construction of long sandbags filled with moistened earth, coiled on top of each other to reach its eventual domed shape, synonymous with adobe architecture. This is an architectural methodology proven successful, and sustainable, throughout history because of its incredible thermal performance. The sandbag construction absorbs the blistering sun during the day and slowly releases the heat in the colder night, and vice versa, absorbing the colder evening temperatures that then cool the structure throughout the following day.

With the SuperAdobe, you don’t need an architect or an engineer or any heavy machinery. You need two hands and locally available earth to fill the sandbags that once erected, result in a large thermal mass of comfort befit for modern living. Its passive thermal features mean the home’s occupants can save on heating and cooling while inexpensively sourced materials save transportation costs during the construction phase. 

Structurally speaking, the SuperAdobe utilises modern engineering concepts to deliver its form. Vertical strength is achieved through the sandbag compression while the barbed wire adds tensile strength. The SuperAdobe was tested under the supervision of the International Conference of Building Officials, who determined the structure could withstand twice the weight it would take to crush a normal pitched-roof house.

Such is the reputation of CalEarth’s designs that they’ve been “studied by Nasa, endorsed and used by the United Nations, featured in countless world media outlets, and awarded the prestigious Aga Khan Award for Architecture.” By integrating traditional architectural techniques with contemporary technologies, the SuperAdobe meets global standards of safety, including California earthquake testing. The sandbags themselves offer flood resistance and fire-proofing, too.

Nader Khalili, Cal Earth FounderMafu Haus, Mozambique

The work of the CalEarth Institute provides an immediate and economic solution to the global housing shortage. They aim to expand their design’s livability and are currently concepting ways to speed up the building process to give shelter to more people, in less time. Khalili’s daughter and current owner, Sheefteh Khalili for example, expressed that CalEarth is working towards applying the SuperAdobe model in more time-sensitive crises like natural disasters and refugee events. Builders would be deployed to site with a small bag of tools and the rest of the construction materials would be resourced from the earth. This is an exciting prospect and one that would spell shelter in time of need, in relatively no time at all.

Long after Khalili’s passing, the CalEarth Institute continues to uphold his vision by educating people in their accessible sustainability practices and earth building techniques through in-person and online educational programs in more than 40 countries across the planet.

Fina Remedio, Puerto Rico

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Aaron Chapman

Aaron Chapman is an Australian artist and writer based in Murwillumbah whose work is motivated by space, memory, and architecture, often considering the concept of ‘home’ and its psychological impact.