Building houses out of straw is something that has been around for millennia but it is something that is coming back in style and for very good reasons. To build using conventional bricks is a great strain on the environment due to all the non-renewable resources needed and the pollution that is caused by forming the materials and it is not particularly efficient in terms of insulation and fire damage.
Andrew Morrison is a leading innovator in building from straw bales and to give you a quick summary of his work, it basically involves taking bales of straw from farms that would ordinarily be burned as an unwanted mass and making large bricks from them in a way that they are compressed so tightly that they are very resistant to fire (due to the lack of oxygen passing through them).
The walls are covered in plaster like normal bricks would be and this together makes them very energy efficient and sound-proofed, due to the density. They last as long as manufactured bricks, at least, as the compactness means that neither air nor water can penetrate them to cause rotting.
This means, therefore, that houses and other buildings can be built from natural, renewable materials that would usually be seen as useless and something to get rid of.
From this, it can be seen that people could start straw bale construction industries without needing too much capital; either ask a farmer if you can take the straw for free or for a minimal cost.
For more details, it would be good to look at Andrew’s FAQ page, where you can also watch some short videos about how it all works.