On CNN.com recently, there was a little piece on the non-acceptance of autoclaved aerated concrete material pursuant to the California Building Code.
According to CNN:
"AAC is a mixture of sand, water, lime, portland cement and aluminum powder that is formed into blocks and cured in an autoclave, a sort of industrial pressure cooker. It has been used in Europe, where it was invented, for more than 70 years.
"Besides being fire-resistant, AAC also deadens sound, is energy efficient, is impervious to termites, is bulletproof and waterproof, generates no waste in its creation, and can be recycled, its fans say."
We all know how important it is to live in a green — not to mention bullet-proof — structure, so one would think that a progressive state like California would allow for the use of this material. Not so, says CNN.com, because AAC has not been tested for its seismic resistance.
" 'Autoclaved aerated concrete cannot be used to resist seismic forces because it has not been seismically tested,' said David Walls, executive director of the California Building Standards Commission in Sacramento. The restriction is based on guidelines from the National Earthquake Hazards Reduction Program, he said."
The AAC situation is illustrative of the issues that accompany incorporating new materials into traditional building codes.
First, you have the issue of overlapping regulatory interests, like promoting energy efficiency and preventing buildings from crushing people during earthquakes.
On top of these regulatory interests, you have administrative considerations. Most states adopt the International Building Code or some form of it on a regular schedule. New materials and products may emerge as salient between upgrades to new code systems. In addition, not all of the code may be adopted.
In this case, California adopted the 2006 IBC without the companion housing code that would have included acceptance of AAC in seismic areas, according to a CNN.com source.
Finally, there are the political considerations. From the AAC example, manufacturers of competing products may intrude with acceptance of the provisions of the building code that allow for new materials.
Greening the building codes is not a simple task -- competing administrative, regulatory and political forces must be managed and balanced. Even with the best of attention to each of these considerations, there will always be examples -- like AAC -- of issues that fall through the cracks.
Shari Shapiro, J.D., LEED AP, is an associate with Obermayer Rebmann Maxwell & Hippel LLP in Philadelphia. She heads the company's green building initiative and writes about green building and the law on her blog at http://www.greenbuildinglawblog.com, where this post originally appeared.
A California House, Not Made of AAC — Image CC licensed by Allan Ferguson.