We spend most of our time In our homes and in our workplace. David Pearson, in his book "The New Natural House Book," tells us, according to studies in the USA, the indoor air can be up to 10 times more polluted than outdoor air samples. Even if the indoor pollutants level are low, we are exposed to them for much longer periods of time. The indoor pollutants are not just a result of outdoor pollution getting into the home - the "sick home/building" syndrome results from widespread introduction of synthetic building materials, finishes, and chemical vapors. In addition to the chemical pollutants, the new energy efficient airtight houses compound the problems of established pollutants, such as dust, bacteria and fungi by creating a breeding ground for them and trapping them in the house. All these unhealthy contributors combine to make a very dangerous environment. In fact, in a recent front page article in the Atlanta Journal & Constitution stated that pollution not only triggers asthma, but can cause it.

Imagine an interior environment which actually is cleaner than the outside air and is a safe haven and refuge from unhealthy pollutants. This is what Heart Craft homes and Petra AAC buildings offer. How are Heart Craft Homes and Petra AAC buildings actually healthy?

AAC is probably the safest building product available. AAC is a non-toxic product that does not pollute the air, land or water. During the manufacturing process, waste from the cutting process is recycled back with raw materials and used again. During construction, there is virtually no waste generated. AAC products were designed to respond to the urgent need to conserve and protect the earth's precious natural resources.

We feel an article from Natural Home Magazine (.com) said it best. In the Mar/Apr 2002 issue, page 39, they quote the book Prescriptions for a Healthy House: A Practical Guide for Architects, Builders, and Homeowners, by Baker Laporte, Elliot and Banta.

"Why consider natural materials such as Petra AAC for healthy housing? Because these historically derived methods of construction differ from standard cavity wall construction techniques in that manufactured vapor and air barriers are not installed to retard the flow of air and vapor through the walls. Instead, vapor and air are allowed to flow naturally through the massive walls. Because temperature change occurs very slowly in the flow through process, and because AAC has the ability to absorb and desorb large amounts of moisture without deteriorating, accumulation from condensation is significant. When a home is properly constructed using these mass wall techniques, it will be an extremely comfortable environment with a, high degree of temperature and humidity stability. Furthermore, because the solid walls themselves provide insulation, the need for synthetic exterior sheathing, batt insulation; gypsum board, joint fillers, and paint is, eliminated. Many volatile organic compound contamination sources are thereby eliminated as well.

A wall made of unprocessed materials through which the flow of air and vapor is unhindered is called a "breathing wall" in the philosophy of baubiologie and is central to the baubiologie concept of creating a healthy dwelling. (Actually, the term "breathing wall" is a misnomer because the walls are not the primary ventilation source for the building. The term "permeable wall" would perhaps be more accurate.) Another baubiologie analogy is that of the building envelope being a "third skin" (our clothing being our second skin). This analogy is a more useful one in describing how a "breathing wall" actually works. Our skin is the organ of contact with the outer environment, and it regulates the balance of moisture and temperature of the body in relation to the environment. Skin must remain permeable to facilitate a healthy interaction between the natural environment and the human organism. So, too, according to baubiologie, must our third skin; the walls of our dwellings remain permeable in order to achieve an optimal environment for health."