The Nautilus model has a strong and elegant shape. Its design is based on a Fibonacci sequence. This particular sequence features numbers calculated by adding the previous two numbers. This creates an evenly spaced shape in the form of a nautilus or snail. This model uses rammed earth walls made out of tires, just like other models. However, the walls of the Nautilus model are also enclosed in straw bales.

The Nautilus gets its name due to its spiral shaped floor plan. The layout wraps around a bedroom loft featuring a fireplace. The opposite bend of the spiral shape plan is made into a cistern for water storage.