North America has experienced three waves of rammed earth building since industrialization. The first twoin the 1840s and 1930swere a response to economic hardship, expressing a quest for low-cost owner-involved housing. And both surges were eventually overwhelmed by the availability of mass-produced manufactured materials. The final wave of rammed earth building began in the seventies, spurred by the energy crisis and the birth of the modern green building movement, and is continuing today as part of a growing movement for natural building. Today the greatest activity in rammed