Why Heart Craft is "The Best Home in the World" with "Patented Peace of Mind"TM Enduring, Economical, And Ecological Petra and Heart Craft strive to be the nation's largest reducer of global warming and environmental problems using current solutions.   FYI - Everything you need to know about Petra AAC & Heart Craft's Autoclaved Aerated Concrete The history, basic facts and scientific data for the neophyte to the expert.