"Straw-bale construction, because of its density, is extremely fire resistant, but it also has many more attractive qualities, Dunham discovered. When it comes to insulation, it beats normal 2-by-4 wall construction hands down. Standard houses' R-value (the measure of a wall's resistance to heat or coolness) ranges from a rating of 13 to 19. With straw bales as insulation, the resistance level rockets to a rate of 40 to 50. Plus, straw is cheap, and, when stucco-covered, it is far less susceptible to termites than wood."
Thanks to Mindy Oliver