First insulating layer is cardboard, this is used pretty widely for insulation but we're using flat boxes as it's also to cover gaps in the timber so that no clay dust comes through from the next layer.
Next layer is called "leichtlehm" - presumably a German invention, it means 'light-clay'. Made with as much straw as can soak up a sand/clay mix and water. You could do this barefoot (I did!) but it's quite prickly.
Then comes the complicated bit - getting it up two stories in a convoy of buckets and pulleys...
Finally it gets put in place, about 10cm thick in the end after much stamping down. As with the cardboard, we're just covering the area over the internal part of the house.