Biocement is a bio-based construction material that combines microbiology and geotechnics to solve invisible underground cracks in saline soils—cracks that drain water and weaken structures. Salt-tolerant microbes produce calcium carbonate to form a “living soil layer” that seals cracks, retains moisture, and restores degraded land. The material is sulfate-resistant, self-healing, and permanently stores up to 40 t CO2 per ton. From agriculture and coastal homes to 3D-printed structures and artificial reefs, Biocement proves that construction can regenerate ecosystems