Insulation:

• Natural Cotton Fiber Insulation: Contains 85% post industrial recycled natural fiber
• Wool Insulation - called "nature's insulation", wool is not redily available in the U.S., at least not in batts. It is redily available in New Zealand, Australia, England and some other foreign countries. Below are some web sites of wool insulation companies:
      Insulwool (New Zealand) - Very extensive, informative web site
      Sheep Wool (Ireland)
      Thermafleece (England)
      Good Shepherd Wool (Canada)
• Soy Based Foam Insulation: This is a soy bean based spray-in-place polyurethane foam insulation. No VOCs or CFCs, no formaldehyde. Not a petroleum base foam like Icynene. These are two companies producing soy foam:
  • Healthyseal
  • Biobase
• Icynene Insulation System: Natural Spaces has a few domes insulated with Icynene foam and is monitoring their performance