What are the advantages of natural building materials?

All these methods are typically more labour intensive and much less capital intensive than modern construction materials...thus even when the costs are overall the same more money is spent on labour and skills development with much less on material and transport.

Earthen buildings - there are many different ways of building with earth.

Simplest constructions i.e. mud brick, cob and earth bag etc make use of a typically abundant locally available material i.e. earth (needs only about 20% clay the rest being silts, sand and gravels (and straw in the case of cob), with only the simplest of tools, enabling one to build for oneself with the simplest of means.

More infrastructure intensive methods/systems like "rammed earth" require shuttering in which to compact the earth. Thus these systems require greater capital investment, typically with less labour than cob or mud brick and are thus more suited to larger more conventional construction companies as seen in Australia where major companies are doing rammed earth at 60% the cost of conventional walling systems (note walls are only approx. 20% of a total building cost depending on the design)

Compressed earth brick - requires expensive earth brick compressing machines and the use of at least 4% cement as a stabilizer....so are more capital intensive....but still produce local jobs which help stimulate local economies and reduce the waste and pollution involved in transport and packaging of standard bricks.....and being stabilized have the advantage of being much less susceptible to moisture so can even be used as face bricks.

For more information on the advantages of Straw bale construction, please see: "What are the benefits of Straw Bale construction? "

For more information on the advantages of Sand Bag construction, please see: "What is the advantage of sand bag construction?"

For more information on the advantages of other natural building technologies, please see: "Are there any other natural building technologies other than Straw Bales? "