Strawbale is probably one of the most eco-friendly building materials available. It's very renewable - it only takes a year to grow and be baled, and is a waste product from grain growing.
Strawbale walls are highly insulated, with an R rating of about 8 (Australian rating). Much higher than standard brick veneer walls which have an R value around 2.
Strawbale has a fairly low embodied energy (the energy required to make it) compared to most construction materials. The only energy used is in the mechanical bailing and the transport.
