Building Healthy Buildings

I recently ran across a book called "Breathing Walls: A Biological Approach to Healthy Building Envelope Design And Construction" (http://www.breathingwalls.com/index.html).

This book has been written by 3 leading building biologists from the US back in 2007 but was never finished and published, so available only in the form of pre-publication draft.

Unfortunately, it is not available in electronic format and can only be ordered in spiral bound laser printed format directly from their Web site.

I have ordered one and read it through, was really impressed with the depth of analysis and amount of knowledge provided and how and why the majority of houses that are built those days become biologically hazardous to their occupants and what it takes/needed to build biologically and much more reliable houses with life times expectancy of several hundred years and more (the majority of the currently built houses will only last couple of dozen years before they start structurally deteriorating, while the houses built in 19th and first half of 20th century were design and built to be much safer and last much longer).

Here is a short excerpt from their Web site:

"Breathing Walls offers practical alternatives to conventional modern building practices that keep homes airtight. Walls built today are energy-efficient but cannot handle the inevitable intrusion of moisture, resulting in mold, ill health for occupants and structural damage. Instead of "build tight, ventilate right," we say make your envelope "waterproof but vapor permeable." We work with, not against, the forces of nature.

Healthy, nontoxic alternatives are provided in our manual for building walls, foundations, slabs and roofs that allow moisture to dry out before mold can grow while effectively insulating your house and saving energy. Contractor-friendly choices include various thick, "breathable" materials, including low-density fiber-cement wall forms or blocks, autoclaved aerated concrete (AAC), and wood log. We also offer a thin-wall option that employs magnesia-based boards, a material extensively used in Asia. Detailed protocols explain the application of these materials on the job site.

Written by building biologists, this is a helpful reference manual for builders, architects, designers and homeowners wanting to build green and healthy."

If anyone is interested in this read, what I can do is to start summarising chapters of the book on a regular basis into this topic and turn this thread into active discussion.

So please let me know if there is any interest and I will be happy to start this journey.

Excellent idea Alex. I too have read a few articles along these lines and found them interesting. In practice though similarly to AW above, I found them to be on the wrong side of the cost benefit ratio but anything that can make our houses healthier, more efficient and more environmentally friendly is a way of the future.

Stewie D

The largest single issue needing to be addressed is mould and 90% of all builds fail to protect the slab edge against water ingress via the capillary action due to direct contact between the slab edge and the ground. The vapour barrier black plastic under the slab is required to continue out from under the slab, come up the face of the slab and terminate level with the finished ground level. This simple NCC-BCA, AS2870 requirement, prevents ground moisture being drawn into the slab up through the slab causing rot in the bottom plate (timber or steel), rotting the carpets sharp-edge/underlay & carpet and creating mould to the floor coverings and building elements within the first 100mm above the slab.

Best option is to use Radmyx concrete additive during the pour in addition to plastic barrier (which sometimes gets damaged).
When using Radmyx solution there no need to put plastic or waterproof under the bricks and framing.


It costs a bit extra but worth every penny.