Is it possible to insulate an Earthship with straw?

Straw Bale Insulation in Earthships

Straw bale insulation has been used in Earthship construction for decades, providing excellent thermal mass and R-values. When used as a primary insulation material, straw bales can achieve R-values of R-30 to R-40 per inch, making them a suitable choice for temperate climates. To achieve this, the bales should be stacked tightly to minimize gaps and ensure a consistent R-value.

Designing a Straw Bale Insulated Earthship

When designing an Earthship with straw bale insulation, it’s essential to consider the thickness of the bale wall. A minimum of 8-10 inches of straw bale insulation is recommended to achieve optimal R-values. This can be achieved by stacking two layers of straw bales, with a 2-inch gap in between for ventilation. The exterior of the bale wall should be protected with a waterproof and breathable layer, such as a clay plaster or a natural fiber mesh.