One side of a hemp wall was exposed to a 650 °C flame for four hours without igniting or failing. On the opposite side, the temperature remained at just 2 °C. This striking outcome reinforces what controlled laboratory testing has already demonstrated: hempcrete is naturally fire-resistant. In standardized ASTM E119 fire-resistance tests, hemp–lime wall assemblies have endured temperatures of up to 925 °C for a full hour while the unexposed surface stayed close to room temperature. Additional re