He built his house with potato sacks and earth: the fascinating sustainable work in southern Brazil

In San Bento do Sul, Santa Catarina, Brazil, an unusual bioclimatic house has captured local attention. Partially buried and topped with a green roof, the structure was designed by Sandro Gilberto Jankoski with a focus on autonomy and minimal environmental impact. Adjacent to the main house, Jankoski also constructed an underground storage facility for food preservation, seed storage, and emergency shelter.

For the primary structure, Jankoski employed superadobe, a technique using continuous polypropylene bags, similar to those used for potatoes or onions, filled with compacted earth. These bags, when filled, formed continuous rolls that were then cut into approximately 15-meter sections. These sections were stacked, molded, and progressively compacted to create walls about 25 centimeters thick before compaction. To ensure stability between layers, barbed wire was placed between each level.

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It is like a 3D printer, but manual.

Jankoski utilized earth sourced directly from the building site, eliminating transportation costs and ensuring the structure integrated seamlessly with its surroundings. He likened the repetitive, layer-by-layer construction method to a "manual 3D printer," highlighting its departure from traditional bricks and concrete. The main structure's construction took nearly a year. While initial stages progressed quickly, the work became more demanding as the walls grew taller, requiring the manual transport of filled buckets without external assistance.

The resulting home boasts significant thermal comfort. The thermal mass of the compacted earth stabilizes the interior temperature, shielding the house from external climate fluctuations. "If it's hot outside, it stays cool; if it's cold, it stays warm," Jankoski explained. A portion of the structure is embedded in a hillside to enhance natural insulation. To combat potential leaks, a common challenge in semi-buried constructions, Jankoski installed a drainage system and high-strength reinforced tarpaulins. The roof features a green covering with natural soil, grass, and vines, further boosting thermal and acoustic insulation while enhancing the organic aesthetic, setting it apart from conventional regional buildings.

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If it's hot outside, it stays cool; if it's cold, it stays warm.