Autoclaved aerated concrete is manufactured as blocks or panels. Shown here are panels being placed for residential walls.

Unlike concrete masonry units, AAC blocks are solid, with no molded core holes. Standard blocks are 8 inches high, 24 inches long, and 4 to 12 inches thick. An 8x8x24-inch block weighs only 35 pounds, so it’s easier to handle than a conventional concrete block. AAC can easily be tooled also, and even cut, drilled, and shaped with woodworking tools. Napier says that there is no other material commercially available that can match AAC for fire resistance. Four inches of AAC has a 4-hour fire rating, making it ideal in commercial buildings for encasing steel columns, surrounding elevator shafts, and for other fire-stopping requirements.

Other reasons people like living in AAC homes include:

  • They are quieter because AAC walls have good sound-insulation properties
  • AAC homes are wind- and water-resistant, and rodents or termites can’t make homes or tunnels in the walls (the soft walls can even stop bullets and shrapnel).
  • The cost and length of time to build AAC shells can be significantly less than for wood-frame construction.