Clay and straw
“Cob” is the (old) English word for a mixture of unfired clay, sand and straw. When kept dry, this material can last for hundreds of years and is a tried and tested building method with many examples around the UK.
Where cob is primarily used to construct the structural, load bearing elements of a building, “light straw” can be used as insulation, much like hempcrete, but with a much lower material cost.
Straw bale buildings have the absolute lowest impact on the environment in their construction. They are also very energy efficient and have acoustic qualities similar to recording studios. Straw bale buildings can be designed and built to any style, with clean lines from formal to curvaceous models.