Cordwood Masonry is a low-cost, energy efficient, easily constructed and aesthetically pleasing building technique in which short logs are laid widthwise within a special mortar matrix. Walls are usually 16 to 24 inches thick. Separating the 4-inch interior and exterior mortar beds is an 8-inch bed of sawdust insulation. The R-value of a cordwood wall is about R-25. The thermal mass of the walls perfectly accommodates passive solar home design. All SMC structures are Cordwood or Strawbale.