The basic method of construction is to use locally obtained earth if suitable, combined with a mix of sand, aggregate, with some cement to stabilize the mix and some waterproofing admixture.
The mixture is heavily compacted between formwork, which when removed produces natural looking earthy walls.
Careful batch mixing and maintenance is however important, to ensure that the finished product is stable, otherwise some areas may weather or degrade as in these photos as additional waterproofing is required every 10 or so years.
As a walling product, it has fantastic thermal value for internal walls and has great sound absorption qualities. External walls can absorb heat and cold, so often insulation (foam panels) can be added during the build.
As a product it is also fire proof, it is termite proof and relatively stable to environmental conditions, although incorporated into a structure, often includes other materials that are not.
Wall thickness varies but 300mm is standard and provides a load bearing wall to support roof framing, although this still requires engineering for council approval.
Fixings such as masonry plugs or anchors can be used, but at twice the normal length of embedment, services such as plumbing and electrical are installed during the build process, so as to not affect the finished wall surfaces.