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Community and Q&A

Bau Biologie – The First Green Building Movement

GBA Editor | Posted in Green Building Techniques on

Materials that are not natural don’t resonate with us, and therefore don’t nourish us – they deplete us. Nature is our ultimate guide.

The role of our buildings is to shelter us from climatic extremes without sacrificing the life-nurturing balance that nature has perfected over eons. Building Biology is both the science and the philosophy that holds nature as the gold standard against which healthy human-built indoor environments must be measured.

The natural environment is a delicate balance of chemical, electrical and biological energies that has sustained life through the millenia. Humans, along with animals, thrive in natural environments with temperature variation, humidity range and complexity of colors and shapes. Understanding the forces that create and maintain both a stimulating and healthy environment and recreating these conditions within indoor environments to nurture us is the work of building biology.

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Replies

  1. Riversong | | #1

    Bau-biologie®, a term coined in Germany, is a word to describe a movement promoting the use of healthy building principles as a means to improve living and work spaces and the health of people who occupy them. Bau-biologie is about how buildings impact life and the living environment.

    The German term “Bau-Biologie” means “building biology” or “building for life.”

    Building Ecology can be defined as the relationship between the building and the environment.

    The phrase “Bau-Biologie® and Ecology” specifically refers to the study of the impact of the built environment on human health, and the application of this knowledge to the construction of natural homes and workplaces; and the holistic interaction of human involvement with the environment and the regenerative sustainability of the environment.

    The underlying principle is one of “balance.” All materials that come from the natural environment make up the “living structure” and will promote health. When these materials are returned to the natural environment they will cause no harm. Problems occur for people and the environment when synthetic materials and man-made pollutants are introduced.

    History

    In post-war Germany, there was such a demand for reconstruction that many new buildings were built quickly and cheaply. This had a devastating effect on the health of a large portion of the population and placed an enormous burden on their health care system. It was discovered that commonly used building materials and certain methods of construction were causing these problems. Today we call these kinds of problems "Sick Building Syndrome" and the resulting human health problems associated include Multiple Chemical Sensitivity (MCS), Environmentally Triggered Illness, Asthma and Allergies to name but a few.

    In light of this, many Germans realized it was better, and ultimately much less expensive, to construct buildings in a healthy manner. As a result, the study of Bau-biologie or Building Biology began and was pioneered by people such as Anton Schneider, Ph.D., Wood Technologist, Hubert Palm, M.D., and Alfred Hornig, Electrobiologist. Over the years guidelines for healthy homes and workplaces were established to ensure the health of buildings.

    Although well known to architects and health professionals in Europe, this specialized science, or way of building and living, is still relatively unknown in the U.S.

    Bau Biologie in the United States

    In 1986 Bau-biologie was brought to the U.S. by a German architect named Helmut Ziehe. He founded the International Institute for Bau-biologie and Ecology (IBE) in Clearwater, Florida. Ziehe translated the original work of Anton Schneider Ph.D into English and was given permission by the Institute für Baubiologie und Ökologie (IBN) in Neubeuern, Germany to teach Bau-biologie in the U.S.

  2. Riversong | | #2

    25 Principles of Bau-Biologie

    1. Make sure the building site is geologically undisturbed.
    2. Place dwellings away from industrial centers and major traffic roads.
    3. Place dwellings well apart from each other in spaciously planned developments amidst green areas.
    4. Plan homes and developments individually taking into consideration the human aspect and the needs of family life and nature.
    5. Use natural and unadulterated building materials.
    6. Use wall, floor and ceiling materials, which allow the diffusion of moisture.
    7. Allow natural self-regulation of indoor air humidity using hygroscopic materials.
    8. Consider sorption of building materials and plants (in- and outside), which allow filtration and neutralization of toxic airborne substances.
    9. Design for a balance between heat storage and thermal insulation in living spaces.
    10. Plan for optimal surface and air temperature.
    11. Use thermal radiation for heating buildings employing solar energy as much as possible.
    12. Promote low humidity and rapid desiccation in new buildings.
    13. Utilize building materials, which have neutral or pleasant natural scents and which do not emit toxic vapors.
    14. Provide for natural light and use illumination and color in accordance with nature.
    15. Provide adequate protection from noise and infrasonic vibration or sound conducted through solids.
    16. Use building materials that do not have elevated radioactivity levels.
    17. Preserve the natural (DC) air electrical field and physiologically beneficial ion balance in space.
    18. Preserve the natural (DC) magnetic field.
    19. Minimize technical (AC) electric and (AC) magnetic fields.
    20. Minimize the alteration of vital cosmic and terrestrial radiation.
    21. Utilize physiological knowledge in furniture and space design.
    22. Consider proportion, harmonic orders, and shapes in design.
    23. Use building materials that do not contribute to environmental problems and high energy cost in the production process.
    24. Do not support products or building materials that over-use limited and irreplaceable raw materials.
    25. Support building activities and production of materials which do not have adverse side-effects of any kind and which promote health and social well-being.

  3. Riversong | | #3

    Planning and Design Criteria of Bau-Biologie

    During the planning and design states of building a biological home, the following eight additional criteria should be considered:

    1. Selection of proper site, including the analysis of the soil and geophysical conditions. Consider climatic factors, which would include prevailing winds, temperature, solar orientation, relative humidity and rain fall.

    2. Selection of proper building materials, both structural and finishing that enhance the ability of the structure to “breathe.” Select natural building materials that allow for self-regulating interior relative humidity that accomplish this task utilizing hygroscopics. Consider using building and plant materials on both the interior and exterior that exhibit sorption and the filtering and neutralizing of toxic airborne substances.

    3. Make careful decisions about energy; consider the use of solar energy, the methods of heat and energy conservation, and the use of thermal insulation. Design for a balance between heat storage and thermal insulation in living spaces that utilize radiant rather than convection heat distribution.

    4. Select appropriate ventilation, water and air filtration systems to establish a healthful living environment. An efficient artificial ventilation system can be used to supplement the natural ventilation of a home. Water systems should be ecological and also non harmful to occupants.

    5. Take care to select the right illumination (light temperature, spectral range, intensity, etc.) for each room. This factor is as important for your well-being as shielding unwanted noise.

    6. Avoid electromagnetic fields, especially in areas of the house where people spend lots of time (bedroom, play and work areas).

    7. When doing the interior design, use furniture that is in proper proportion to the residents; use materials that do not outgas and create static electricity.

  4. Riversong | | #4

    Any thoughts?

  5. Jack Woolfe | | #5

    “Materials that are not natural don’t resonate with us, and therefore don’t nourish us - they deplete us. Nature is our ultimate guide.

    The role of our buildings is to shelter us from climatic extremes without sacrificing the life-nurturing balance that nature has perfected over eons. Building Biology is both the science and the philosophy that holds nature as the gold standard against which healthy human-built indoor environments must be measured.”

    While I think I agree with many of the aspirations of Bau-biologie I’m not sure that I am comfortable with your initial statements. It doesn’t appear to me that “Nature” is intentionally helpful or harmful – it just is. There are many aspects of “Nature” that are quite harmful to humans: cosmic rays, nuclear radiation, coronal mass ejections, volcanoes, typhoons, extremes of hot and cold, etc. I don’t see that “Nature” provides any sort of a standard to which we should aspire. Some aspects of nature are benign towards human life, other aspects are anything but.

  6. J Chestnut | | #6

    I had my home inspected by a Bau-Biologist for electrical and magnetic fields. Because my electrical service was grounded to my copper plumbing it was demonstrated (with a Gauss meter?) that a magnetic field was induced by stray electrical current. My home also contains some old knot and tube wiring which set up electric fields (measure by another instrument whose name I don't recall) and the strength of the electric fields were above the thresholds determined to be safe by the Bau-Biology institute.
    To remediate the magnetic field I had a dedicated copper ground rod installed outside the house so I could take the stray current of my copper piping. To remediate the electric fields in the areas of the house where we slept we installed a switch that would turn of the circuits whose electric AC potential induced the electric flelds.

    When my wife and I moved into our current home several years back she was having difficulties sleeping. I had thought the remediations to our sleeping areas would help but they did not seem to have any effect. (Later when we bought a dog she began to sleep well, and conversely I started to have difficulty sleeping ; ) )

    I have for a long time stopped turning off the circuits to extinguish the electric fields in our sleeping areas. I don't notice a difference in the quality of my sleep on way or another. After the remediation I (very subjectively) felt that I was a little "less edgy" which I attribute to the canceling of the magnetic field. I can't be confident about this however.

    What does clearly "get on my nerves" in my home is the condenser on the refrigerator. We have a bedroom above our refrigerator which I avoid for sleeping. When I'm designing homes I try to keep the frig as far away as sleeping areas as possible.

  7. Riversong | | #7

    Jack,

    First, none of these are my words. They are all quoted directly from the Bau Biologie movement.

    Second, nothing here suggests that Nature is intentional or willful. On the contrary, it is our willful disregard for natural law that is leading us on a fast track to a precipice. You're right that "nature just is", and accepting Her laws of balance and harmony allows us to "just be".

    You can't see the value of nature because you're looking at it backwards - which is precisely why we build houses and our entire world in service to our own egos and at the expense of the rest of the biosphere and the life support capacity of the planet.

    Nature doesn't set a standard, but rather a perfect model of internal harmony that allowed life to grow and flourish for 3.5 billion years, and human life to flourish for 2.5 million years - until what we call the historical period, the beginning of civilization. It is only in the last 10,000 or so years - a flicker of time - that we humans have ignored the laws of natural harmony and created an artificial world which is destroying us and much of the rest of our fellow species.

    Evolutionary biologists know that any minute deviation from the critical balance of forces, elements and relationships would have made life impossible on earth, and yet something – call it Nature or Gaia or God – has created and maintained the most intricate conditions necessary for life to flower on this little planet. That field of science also knows that the expression of our DNA blueprint requires a constant interaction with the Architect - the natural environment.

    Bau Biologie is one attempt to relearn those natural laws that we've forgotten or neglected. Other building movements that are trying to rediscover and work within Nature's laws of balance and harmony are the Natural Building movement, the BioPhilic Architecture movement, the Regenerative Architecture movement, the Permaculture movement and the Deep Ecology movement. Feng Shui, Sacred Geometry and Geomancy are other more esoteric arts that are based on principles of natural balance.

    The so-called "green" building movement, on the other hand, is moving farther away from Nature's principles by creating more hermetically sealed boxes made of petrochemical plastics that are completely dependent on artificial life-support systems. We are, in fact, building life-containment units that are more like space ships than homes, isolating ourselves from the source of our being as if Nature were truly a malevolent creature against which we must protect ourselves.

    The more we isolate ourselves from Nature and Nature's laws the more sick we become, both in body and as a culture. It is past time we rediscover our birthright and our humble place in the natural order, stop fighting and make our peace with Nature. Bau Biologie is but one attempt at doing that.

  8. Riversong | | #8

    Chestnut,

    The Bau Biologie movement is perhaps the only science that investigates and attempts to mitigate, the health impacts of electro-magnetic fields. The fields are weak, but their interactions with the earth's magnetic field and our own physiological energy fields can be dramatic, even if poorly understood.

    The human body is composed of a quadrillion living cells, 90% of which are not human but necessary to our survival (we are truly a microcosm of a natural community). Each cell has 400 billion molecules conducting millions of electro-chemical processes between trillions of atoms, such that there are a septillion cellular actions occurring simultaneously at any time within our skins, each of which is mediated by minute electro-magnetic fields.

    In truth, the human body is infinitely more complex than anything the human mind and hand can create, and we don't have a clue what our artificial EMF, microwave and RF fields are doing to that intricate internal dance.

    We co-evolved with Nature's cosmic radiation and background ionizing radiation and the earth's and sun's electro-magnetic fields. But, just one generation, we've bathed the earth in fields she has never known and to which our bodies have not developed immunity. We are, in so many ways, treating ourselves (and the rest of nature) like laboratory rats for our own amusement. Is it any wonder than the bee colonies are dying off and the bat populations are plummeting? Those creatures live by reading the energetic fields. We are jamming Nature's signals and filling the magnetosphere with noise.

    We are playing God without an instruction manual.

  9. Jack Woolfe | | #9

    "The so-called "green" building movement, on the other hand, is moving farther away from Nature's principles by creating more hermetically sealed boxes made of petrochemical plastics that are completely dependent on artificial life-support systems. We are, in fact, building life-containment units that are more like space ships than homes, isolating ourselves from the source of our being as if Nature were truly a malevolent creature against which we must protect ourselves."

    Most of us spent the first nine months of our lives in a hermetically-sealed box on artificial life support, being protected from a less-then-friendly Nature. Every time we put clothes on or build even the simplest shelter we are artificially altering the natural environment. I see other animals in Nature doing the same. I feel I'm in good company.

    I don't see that other animals are particularly adept at keeping well-balanced with nature. I think of the cyclical lynx-hare population, where the the lynx eat too many hares, causing the hare population to crash, causing the lynx population to crash, causing the hare population to rebound, causing the lynx population to rebound -- ad infanitum.

    We humans, more so than any other other animal, have the ability to modify our environment (for better or for worse), but also the ability to project into the future the results of today's actions. Sometimes we make good long-term choices, and sometimes not. I appreciate these and other discussions about the long-term consequences of our actions, however I don't feel that Nature offers us any particular Gold Standard. We just have to work with what we have, and with what is.

  10. Aj Builder, Upstate NY Zone 6a | | #10

    Bravo Jack Woolfe, bravo ++

    Robert, the masses, billions in cities today. What would you have them live in? And what do you propose to do with all the rest of the unatural existing world already built? I love your ideas as they can be put to use in rural living like where I live but few of us live out of the city around the planet.

  11. anonymous poster | | #11

    I believe that if all who post to this thread came here with the idea of working together we would really have an ability to move sustainably into our future. Keep your differences but at the same time start to find your similarities and work from there positively to and for the good of all nature and life on Earth.
    Merry Christmas, Happy Holidays and more

  12. User avatar
    Michael Maines | | #12

    Robert, I didn't know about Bau-Biologie but it reminds me of Biologique agriculture in France, similar to the ideals behind true organic agriculture and not the Federally-approved version that exists today.

    A book I'm reading now that you might enjoy, written by farmer Will Bonsall, director of the Scatterseed Project, the largest contributor to the Seed Savers Exchange: http://yarotales.net/index.htm. I don't normally read novels, preferring nonfiction, but it's a "futurist" novel depicting a world I think you (and other folks here) would like to live in. Will's approach to farming is much like your approach to building, in tune with nature's rythms, and that's the central theme in his book.

  13. Lucas Durand - 7A | | #13

    Robert, the masses, billions in cities today. What would you have them live in? And what do you propose to do with all the rest of the unatural existing world already built?

    Maybe as "Anonymous Poster" suggests, it's time to start working together. Let's all try to forget about "what is", and re-define our collective notion of what "should be".
    It's impossible to say what the answers are if you don't even know what you are trying to achieve.

  14. Riversong | | #14

    Most of us spent the first nine months of our lives in a hermetically-sealed box on artificial life support, being protected from a less-then-friendly Nature.

    There's nothing "hermetically sealed" about the womb. The fetus is in a fluid environment that depends completely on constant interaction with the host (the mother), which in turn depends entirely on constant interaction with its host (the natural world). We now know from developmental biology that the healthy growth of the fetus is dependent not only on what the mother eats but also on her moods, on the sounds and vibrations of the external environment, on how much love and support the mother receives, and of course on the physical and energetic toxins that pass from the outer world into the placental world.

    Nothing in Nature is hermetically sealed. All boundaries are permeable and conditional. The expression of our genetic blueprint - our DNA - is controlled by the Architect we call Nature, as the field or epigenetics is discovering.

    Every time we put clothes on or build even the simplest shelter we are artificially altering the natural environment. I see other animals in Nature doing the same.

    Yes, all creatures, including plants, alter their surroundings - as do the winds and the waters. But humankind is the only creature that doesn't do so in a reciprocal, participatory way. We are the only creature (and only since the start of civilization) that thinks of "the environment" as separate from ourselves, available for our use, exploitation and enjoyment.

    I don't see that other animals are particularly adept at keeping well-balanced with nature.

    Any creature, including homo habilis to homo sapiens, that has survived for millions or billions of years has done so only by being part of the well-choreographed dance of life. Your vision is much too blindered. If you only see the annual population swings of predator and prey and don't see the millennial old dance of which they're part, then Nature's going to appear as "red in tooth and claw" rather than the incredible example of long-term harmony that She truly is.

    We humans, more so than any other other animal, have the ability to modify our environment (for better or for worse), but also the ability to project into the future the results of today's actions. Sometimes we make good long-term choices, and sometimes not.

    For at least tens of thousands of years, human clans and tribes based their actions on the effects on "the next seven generations". They could project just far enough into the next season and the next generation to understand that they had to limit their impacts on the world which sustained them. And they all knew that world to be itself holy and magical and completely alive. They understood in their bones that they were intimately related to every animal and plant, every hill and river, every rock and cloud.

    On the contrary, modern humanity has divorced itself from that kind of relational intimacy and responsibility, and has exhibited an extremely poor record of prognostication into even the near future. Today's corporate, consumer culture doesn't even do very well on our "five year plans" and is constantly caught by surprise by such things as market bubble collapses and blowback from our foreign policy, let alone our impact on the climate, topsoil depletion, water and air pollution, forest degradation, and species extinction.

    I don't feel that Nature offers us any particular Gold Standard

    Then you need to take off the blinders and discover Nature. Because, in fact, She is the only standard we have on this fragile planet.

  15. Lucas Durand - 7A | | #15

    It's impossible to say what the answers are if you don't even know what you are trying to achieve.

    For starters, I wonder if the building industry could organize itself to abandon the use of certain materials (like foams of all type) altogether - except for the most necessary applications.
    - European designers don't appear to rely on huge quantities of foam to achieve high-performance.
    - A myriad of alternatives to foam insulation exist if the problem is tackled at the design stage.
    - A wider selection of alternative insulations could be easily innovated if there was demand.

    One thing I have noticed is absent from the North American building supply market are products similar to those manufactured by Pavatex - structural, moisture-permeable, insulating panels made from natural materials.
    The facilities exist on the continent to manufacture wood pellets by compressing waste wood fibre. It wouldn't be a giant leap to manufacture engineered panels instead of pellets and the wood fibre would almost certainly serve us better as insulation than as another type of manufactured fuel.

  16. Riversong | | #16

    A biological insulation panel grown in the US of A should be available in 2011: Greensulation mushrooms grown from seed husks into rigid insulation or SIP-type panels.

    Grow Your Own

    "Greensulate™ is literally grown, not manufactured. We use a growing organism to transform agricultural byproducts, like cotton burrs and rice hulls, into energy-efficient insulation. Our patent pending process is inspired by the efficiency of nature, and uses a filamentous fungi (mushroom roots) to bond seed husks into a strong rigid board."

    "Greensulate™ is safe to touch and can be installed with out any special safety gear. Additionally there are no spores or allergy concerns associated with the use of this material, and Greensulate™ passes ASTM tests for mold growth, water sorption, and vapor transmission. Best of all, Greensulate™ is chemical and VOC (volatile organic compound) free, while still providing a class 1 fire rating."

  17. ROY HARMON | | #17

    Lucas Durand, I like the way your talkin here! Thank You
    Great post Robert, This is what it's about.
    If the site members, ( and administrators) could focus more on the natural path, effectivness would be magnified considerably. Natural advertisers don't pay the bills though.

  18. Riversong | | #18

    Natural advertisers don't pay the bills though.

    On another thread, someone pointed out that Building Science Corp. is heavily funded by the foam insulation industry, so it's no surprise that they tend to emphasize petrochemical options.

    We can only wonder why the primary GBA editor and blogger is so fond of petrochemical insulation options even though he, like Dr. Joe, understands the benefits of natural materials.

    As an aside, I wrote an article several years ago for Technical Rescue magazine called "Is Fail-Safe Really Safe", which was critical of a number of popular rescue belaying devices that were advertised in the magazine. The editors were quite skittish and wanted me to tone it down, which I refused to do. They published it, because I was at the time one of the leading experts on rope rescue, but for the first (and I believe last) time in their publishing history, they printed a disclaimer to distance themselves from the author's conclusions.

    Advertisers rule the publishing industry, and we can only guess at how much they might influence the opinions and recommendations of the GBA editors and advisors.

  19. ROY HARMON | | #19

    The unfortunate truth for humans is currently stuck in the middle of the numbers $$$ truth $$$

  20. User avatar GBA Editor
    Martin Holladay | | #20

    Robert,
    You wrote, "We can only wonder why the primary GBA editor and blogger is so fond of petrochemical insulation options."

    Of course you are free to wonder. But I have never been told by my employers to alter any of my published opinions in order to satisfy an advertiser. It just hasn't happened.

    Moreover, there's a fair amount of evidence that Icynene was unhappy with my blog, It’s OK to Skimp On Insulation, Icynene Says. Nevertheless, my employers never questioned whether it was a good idea to report on the issue.

  21. Timmy O'Daniels | | #21

    "Is Fail-Safe Really Safe"

    Fail-safe devices (techniques etc.) fail by failing to fail-safe.
    Which is where redundancy comes in - there's an independent back-up which will do the job when the primary system fails. The relevance to building? Simply compare the multi-layered, robust, imperfection of traditional building techniques with the 'optimized' single-perfect-envelope designs which occasionally appear on this forum.

  22. Lucas Durand - 7A | | #22

    I think of the cyclical lynx-hare population,...

    Everything else being equal, this is balance - over time.

    Sometimes we make good long-term choices, and sometimes not.

    I can easily argue that humans make very, very, very few choices that take proper consideration of future consequences.
    What is your perception of "long-term"? 50 years? 100 years? 1000 years?
    Many of the materials that we are using in the built environment may do their job and "perform" well for the life of the structure, but then what? More polyurethane for the land-fills?
    How do those materials interact with the environment once we're done with them?
    What side effects will they have and for how long into the future will those side effects have an impact?
    What proportion of recyclable materials are rendered into "monstrous hybrids"?
    The answer is: nobody knows. We all just assume everything's "under control".
    One thing for certain is that we produce a whole lot of stuff that "nature" isn't familiar with and can't deal with except over the course of thousands if not millions of years.

  23. Riversong | | #23

    Martin,

    I'm glad to hear that you've felt no pressure from Taunton and I appreciated your critique of the deceptive Icynene approach to R-value.

    But, when commercial sponsorship pays the bills, it's impossible to discount its effects. Much recent evaluation, for instance, of medical research has shown a strong bias - which may be unconscious - toward results that support the financial interests of the sponsors.

    And you published here a letter from Bill Hulstrunk which was pointedly critical of Building Science Corp. for its apparent bias toward the products of its financial supporters. The same critique can be fairly directed toward GBA. It's the price of commercial support.

    And the crazy thing about the web is that I doubt the advertisers much care whether they are praised or criticized on-line, as long as they're mentioned - because that increases the number of search engine hits and makes it more likely that surfers will see their commercial messages. For instance, right now there's an ad to the right of this box for foam kits even though this thread is critical of foam.

  24. User avatar GBA Editor
    Martin Holladay | | #24

    Robert,
    I'm glad to see that you noted that GBA, in addition to including a link to the Building Science article, also chose to reprint Bill Hulstrunk's response.

    Believe it or not, I believe that if all arguments are heard, the truth will eventually emerge. It's up to GBA readers (as well as some of our bloggers) to evaluate the evidence marshaled by proponents of any particular position. The more evidence presented -- ideally, evidence based on solid research -- the more likely that a stated position will stand the test of time.

  25. Riversong | | #25

    Fail-safe devices (techniques etc.) fail by failing to fail-safe.

    Timmy,

    I fully agree that lack of redundancy is a major problem of "perfect" systems. But my primary argument in that article about rescue belay systems was psychological as well as technical: that the reliance on "perfect", or in this case presumably "fool-proof" and "fail-proof", systems creates a complacency that mitigates against the kind of good, old-fashioned attention, vigilance and care that results in a successful, safe and reliable outcome.

    I also explained that the term "fail-safe" originated in the nuclear weapons industry - one in which system breakdown is simply not acceptable. So multiple redundancies were engineered into the complex technologies so that, should a nuke beak down, it would do so in a "safe mode". It is for this reason, among others, that I prefer an exhaust-only ventilation system with passive make-up air inlets – a system that can fail (power outage) and still allow some minimal passive ventilation (fail-safe). It is also for this reason that I prefer hygroscopic materials that can passively tolerate sudden changes in relative humidity or minor leakages because of their ability to quickly redistribute and then slowly release absorbed and stored moisture. It's the equivalent to a storm runoff retention pond to prevent flooding.

    And, no technology - particularly complex ones - can ever be made "fool-proof" or "fail-proof". Murphy's Laws remind us of this, and it would seem that our educational (enculturation) system is cranking out more and more fools every day to keep Murphy in business.

    The most reliable way to approach "fool-proof" is to KISS (keep it simple and safe). The more high-tech our systems, the more steps required to make them complete and integrated, and the more critical each individual element becomes to the function of the whole - the more likely it is that some darn fool will mess something up, or even the most careful practitioner will occasionally miss a critical detail.

    So, in addition to the inherent criticality of "perfect" or non-redundant and non-resilient systems, our reliance on them increases the "complacency tendency" as well as the "distraction factor" which can result in minor imperfections that create major problems.

    In the article, I also talk about the risk matrix that I used when I was a town emergency management coordinator (see below). It plots the probability of an event against the consequences of an event. Risk managers put most of their attention on high probability, high consequence events (like flooding from heavy rains), and avoid mitigation strategies that may worsen outcomes (such as pumping stations that may also fail during a storm). And intelligent community planners will avoid situations (like building in floodplains) which require disaster prevention systems that, themselves, are likely to fail when most needed.

    With modern house construction, we know that diffusion and condensation is a low probability, low consequence event compared to major air leakage and exterior rain leakage which happen regularly and cause extreme localized problems. Intelligent designers will avoid building strategies which, while intended to prevent such problems, may exacerbate them in the event of a system failure. These are, typically, the "perfect" systems, such as carefully sealed exterior rigid foam, which are aimed at low-probability events such as diffusion-condensation but which can trap moisture from high probability events such as rain leakage if there is the slightest weakness in the system. Additionally, most of these "perfect" systems have no natural redundancy, such as moisture buffering and redistribution capacity - so additional "perfect" systems must be coupled with them, such as rainscreen technologies.

    Which brings us back to the Bau Biologie approach that recreates the inherent resiliency of natural systems.

  26. Riversong | | #26

    The more evidence presented -- ideally, evidence based on solid research -- the more likely that a stated position will stand the test of time.

    All scientific research, by its very nature, is biased. Even ignoring the potential bias due to funding sources, every experiment starts from a set of assumptions, is limited by the selected focus, is constrained by the choice of methodology, and is distorted by the interpretation of the results.

    The great ancient architectural wonders of the world, as well as the shelters of indigenous cultures were not built with materials and methods that were validated by scientific research. They relied on the native intuition of their architects, a wisdom derived from the careful observation of the natural world and a distillation of nature's laws. And it is these approaches which have, in fact, stood the test of time. Nothing we've created by modern science can claim that validation.

    Research can be useful, but it necessarily involves a narrowing of perspective. What we need most today is a broadening of perspective so that - once again - we see the forest as well as the trees.

  27. Riversong | | #27

    The OP for the "No one wants to do Advanced Framing" thread just edited his original question, so it bumped the thread to the top of the list, and I noticed a response that I hadn't read before but which perfectly addresses the foundations of Bau Biologie - so I'm copying it here:

    Robert

    As a builder/designer, project supervisor and former Building Technologies Instructor with some 40+years of experience, I can only say; a big 'thanx' that you are out there. That you continuously trying to remind the various design and building 'communities' about the reality of construction. I too, am often astounded by the proposals espoused by so many 'experts' that the ideal home/structure is similar to a dry cleaning bag, efficiently sealed, and provided with one hole to discharge stale air, another to introduce fresh air, provisions of course being made that the opening(s) be sized correctly to provide for the number of inhabitants, the activities undertaken by the occupants and controlled by high tech systems, which demand ridiculously high energy for manufacturing, and a constant energy demand.

    And this seems reasonable to most super tight structure advocates.

    As you say, we do transpire and we do breath, everything on this planet breathes and/or transpires, but according to them a building must not - except by the aforementioned unreliable, costly and short life term technology guiding it. Kind of like a pacemaker (well- they are amazing), but ignoring the initial creation of a healthy heart. As well they tend to ignore that we, that is all lifeforms, utilize the energy of the sun, and all its various atmospheric influences, [even those life forms deep within the ocean,(although some may not comprehend the 'link' with them)].

    I constantly amazed and confused as to why - the green/energy efficient experts do not/will not recognize that in order for our buildings to be efficient we can and must quite simply emulate the systems of our environment/ecology. Natural systems that have been so efficient for millennium. Yet they insist on advocating designs that ensure we isolate ourselves or our buildings from the environment, and conflict with the ecosystems around us.

    Breathing, transpiration, reflection/retention/transformation/utilization of solar energy in its myriad forms, these are only a few of the many freely available insights/lessons our planet and its ecology offers us, there is so much more that we have only just begun to realize. Unfortunately, so many still believe and insist that is only by disconnecting and isolating buildings can we be green or energy efficient. Mmmm, I wonder?

    Keep up the challenges, I for one continue to do so in all my design, consulting and building projects, and continue to look forward to your insights, wisdom, and critiques.

    Thanx!!!!!

    ANSWERED BY SMALLD
    Posted Wed, 07/07/2010

  28. mike eliason | | #28

    if you're going to argue about scientific biases, at least get your scientific analogies correct.

    uber-airtight buildings breathe. in comparison to natural systems (e.g. a human body), the lungs are the ventilation system (e.g. HRV/ERV). windows can be opened. it's far from a 'dry cleaner bag'.

    skin doesn't 'breathe', it's nourished from the inside. the misnomer 'letting the skin breathe,' is in reference to applied materials (e.g. makeup/lotion/etc) and is more akin to a diffusion open wall assembly.

    the human body has one hole to introduce both fresh and stale air, and another to diffuse really stale air.

    buildings that allow unfiltered leaky air have more pollution in them than airtight buildings. they also have higher energy usage. these are two of the many reasons that baubiologie groups in europe advocate the passivhaus standard.

  29. ROY HARMON | | #29

    Lets look at the bottom line. Natural homes can easily be built today offering higher than normal efficiencies from every aspect. The cost to build these homes can be as much as 30% less than most other conventional green techniques. In fact, the normal jargon that is projected to the public these days seems to pre-condition them to the fact that building green will cost more.
    The stigma of more cost to build green is already in place. The truth about what can be done, and should be done is kept neatly tucked away by those profiting from the more expensive, heavily marketed green materials industry." More money" is" more green" seems to be the evolving mindset. The shame of that is, that the same folks raking it in are well aware of the better, more green, healthy and far more cost effective natural home construction methods. Is greed natural??

  30. Riversong | | #30

    Mike,

    I was quite clearly reproducing someone else's post here. Those were his words, not mine. However...

    skin doesn't 'breathe'

    It most certainly does. Respiration has to do with air and CO2 exchange through the lungs only on the most gross and superficial level. The heart of respiration takes place at the cellular level.

    Cellular respiration involves the diffusion of molecules through the semi-permeable membrane of the cell wall, which is the paradigmatic biological "skin" that conditionally separates the living world from its life-support environment. Without diffusion through the enclosing "skin", there is no life, since life is essentially a counter-entropic mass and energy throughput phenomemon which converts solar energy to electro-chemical energy which becomes food for other throughput phenomena.

    from Breathing Walls: A Biological Approach to Healthy Building Envelope Design and Construction:

    Breatheability: The Key to Building Performance

    The most primary element of a wall is "self-regulation of moisture".

    "To satisfy the building biology criteria...our building materials must be permeable, hygrosocopic, and have the desired degree of capillarity. We call these characteristics breatheability."

    In fact, the bulk of "breathing" in the living world occurs through the "skin" of the leaves of trees and other green plants which not only transpire enormous quantities of moisture but also CO2 and Oxygen, without which animal and human life would be impossible.

    All biological skin is semi-permeable to allow a constant exchange with the environment, in a dynamic interaction or unceasing flow. Flow and relationship are the essence of life.

  31. Riversong | | #31

    Is greed natural??

    Natural Selection's Paradox: The Outlaw Gene, The Religion of Money, and The Origin of Evil by Carter Stroud, 2008

    Convinced that greed and deception are the ruination of the species, Stroud theorizes that humans are essentially devolving because they’re adapting to the wrong stimuli.

    May natural selection contain seeds of our destruction? Do unintended consequences haunt our means of production? Carter Stroud observes an adaptive humanity on a dangerous path, one in which we increasingly adapt to our own tools and artifacts—such as money—rather than the ecology that actually defines us.

    It's MINE, ALL MINE!

  32. Aj Builder, Upstate NY Zone 6a | | #32

    Roy Harmon, A billion people living in cities, high rises..... 5 to 20 stories tall and more.

    Tell me how to build a straw building to house such??????????????

    I'm listening...

  33. Aj Builder, Upstate NY Zone 6a | | #33

    My answer is, tear down the cities. It would be the only way. And adopt worldwide population laws, one child per. What would result? The mass disruption would leave many dead or dieing miserably. Only a few Riversongs and Holladays left eating from their root cellars, oh wait but a few others... that won't stop evolving.

    So after that, we still would have technology if any of us survive. Life will continue evolving, and now we are passing the torch to non bio life, silicon and whatever else is starting to "be." Man is not the problem. Man is just a stepping stone along this time continuum.

    Bau Biologie for "all" of us is pie in the sky talk. I like it for rural (two dimensional) living, but tell me how you are going to take this to the masses that live in ten story buildings?

  34. Riversong | | #34

    Obviously, the answer is Icynene. The answer is always Icynene (or 42).

    Or, maybe, it's Ice Nine - the precursor to Icynene.

  35. ROY HARMON | | #35

    AJ...Aj...aj....,
    I don't know of anyone visiting this site that speaks of building highrise buildings or attempting to re-locate those that choose to live in them. Maybe at the time there was no better housing choice being offered that fit the life style of the city dwellers.
    Since you have mentioned it though I will share some of the high rise facade restoration experience that I've accomplished . I like the masses term~ It's what I'm about.
    Out of respect for the content of Roberts post here I will create a separate post to share these experiences and opportunities this evening.
    Regarding the homes that are refered to on this site, Natural homes can just as easily be built for the masses as any other type of individual home or housing complex.
    You need to spend less time on the emotional, cutsie pie come back stuff and more time thinking logically about what can easily be accomplished. You seem to have a lot of great green energy all bottled up, just screaming for the chance to produce. Harness it and contribute even more than you already do.

  36. ROY HARMON | | #36

    D

  37. Riversong | | #37

    Wow. This guy just showed up, claiming he's an interdependent clause or some such thing. I think he's from the Bau (biologie) Haus movement, ancient order of Green Men.

  38. Lucas Durand - 7A | | #38

    Seriously though, if it were to be a priority it would not be that difficult to abandon the practice of mass-application of foam products in the building industry.
    I will concede that certain foam products have value in niche applications.
    The europeans appear to already be doing this.
    There are plenty of people who visit this site who have the opportunity to specify alternatives in their designs - if they would consider it a priority.
    "Green" building is a frontier.
    Opportunities to establish new paradigms don't happen every day.

  39. Riversong | | #39

    new paradigms don't happen every day

  40. mike eliason | | #40

    robert,

    in plants, the skin does breathe.

    in humans, the skin does not breathe.

    blood vessels in the dermis nourish the stratum basale, the first (of 5) layer of the epidermis (the outermost layer of your integumentary system). the outer layer of the epidermis is composed of keratinized (dead) epithileal cells that lack nuclei. there is no gas exchange, there is no nourishment. there is no respiration. just continual sloughing of dead cells.

    hence, there is no 'breathing'

    it's basic biology.

  41. Riversong | | #41

    Mike,

    To understand how all nature breathes, it's necessary to graduate beyond "basic biology".

    To believe that the infinitely complex inter-relationship between the body and the environing world is either defined or limited by our skin is akin to prescientific superstition.

    Even the simple "sloughing of dead cells" is a form of respiration - or mass and energy exchange - with the world outside the integument. Additionally, the skin excretes bodily wastes and maintains thermal homeostasis through perspiration, it receives solar energy and converts it to vitamin D, it is the body's the largest medium of neural interaction with the outer world, and a primary receptor and transmitter of pleasure.

    Each of these are forms of respiration, understood more broadly than the simplistic exchange of gasses (though simple organisms exchange gases directly through the integument). Wiser cultures than our own, those more fully immersed in the real world rather than the abstract world of the mind, have always understood respiration - inspiration and expiration - as a transfer of Spirit into and out of the body.

    Respiration, fully comprehended, is the reciprocal exchange of matter, energy and spirit which defines and sanctifies Life.

    If we wish our homes to be "temples of the soul", then they must also serve to intimately connect - rather than separate - our bodies, hearts and souls to the environing world.

  42. Lucas Durand - 7A | | #42

    Life will continue evolving, and now we are passing the torch to non bio life, silicon and whatever else is starting to "be."

    Reason for edit: Being "nicer".
    Happy xmas.

  43. mike eliason | | #43

    robert,

    there is neither respiration, breathing, nor cellular respiration in the outer layers of the epidermis. you can't talk about advanced biology if you don't understand the principles of basic biology.

    also, per your (albeit incorrect) example, an 'excessively' airtight passivhaus wall would be biologically accurate: airtight, insulative and weather resistant with energy (heat) and mass (vapour) 'respirating' through the 'wall'

  44. Riversong | | #44

    Mike,

    Repeating your reductionist ad absurdum argument (based on a high school understanding of biology) only proves your inability to see the forest for the trees.

    The primary standard for Bau Biologie is that a house, like everything in nature, must have a breatheable integument. If you don't understand that, then you understand neither biology nor Bau Biologie.

    In fact, the most effective and efficient building technology in the offing is Dynamic Insulation, which is an air and vapor permeable envelope system that provides high levels of filtered and conditioned air with a theoretical zero heat loss. This approach, also called the Dynamic Breathing Building System, uses an insulating filter media in the envelope, coupled with the exhaust-only ventilation system that I've been advocating for years, to reclaim up to 100% of the outgoing heat while subjecting the incoming air to a higher degree of filtration than is possible with any other system.

  45. John Brooks | | #45

    I can understand why extreme airtightness(0.6 ACH50) may not be worth the effort.
    I still don't understand what is "wrong" with extreme airtightness.

    Robert,
    Exactly how (air) leaky should a house be?
    How tight is too tight?
    And exactly where should the air leaks be?

    Edit to say
    I know you explained why you believe it is not worth the effort in this thread
    http://www.greenbuildingadvisor.com/community/forum/energy-efficiency-and-durability/18807/hermetically-sealed-boxes-beer-coolers?page=6

  46. Lucas Durand - 7A | | #46

    Good question John.

  47. John Brooks | | #47

    Is the purpose of the Air Leakiness for the health of the occupants or the enclosure

  48. Riversong | | #48

    John,

    My ideal of a healthy, efficient, durable cold-climate house is one that relies on hygroscopic, moisture tolerant materials to handle routine fluctuations in relative humidity as well as minor air leakage - but has enough accidental and engineered air exchange to operate passively even when the grid is down or the occupants override the ventilation system.

    To my mind, a house that relies completely on artificial life support systems is not a Passive house. It needs to breathe - both moisture and air - at least minimally on its own without sacrificing durability.

    I don't have any hard proof of the "right" level of air leakage, but from my experience and study believe that 2 ACH50 (approx 0.10 ACHnat) is probably as tight as is necessary - with hygroscopic materials - to maintain durability, and - combined with an exhaust-only system (which minimizes exfiltration when it's running) and strategically-located passive make-up air inlets - allows minimal passive "respiration" without mechanical ventilation.

  49. John Brooks | | #49

    I don't know much 'bout biology........
    But I do know that my skin feels "better" with nothing against it or with only cotton

  50. Lucas Durand - 7A | | #50

    To my mind, a house that relies completely on artificial life support systems is not a Passive house. It needs to breathe - both moisture and air - at least minimally on its own without sacrificing durability.

    So, it isn't so much "air-tightness" that bothers you but a reliance on mechanical/powered systems that does?
    I understand this. Simple is beautiful.
    In your opinion Robert, could <1ACH50 ensured?

  51. Riversong | | #51

    I do know that my skin feels "better" with nothing against it or with only cotton

    My skin feels better with a woman against it.

  52. Riversong | | #52

    could <1ACH50 be considered not-too-tight if provision for adequate passive ventilation is ensured?

    If it could be accomplished easily and inexpensively, without artificial or non-breatheable materials, or the presumed reliability of tapes and other such nonsense, then sure. If it floats your boat to make the house super tight and then punch holes in it, why not?

    The colder the climate, the tighter the house will need to be, and a better target than ACH50 would be 0.10 ACHnat. I think that's enough air exchange to avoid indoor health crises during a power outage.

  53. Lucas Durand - 7A | | #53

    If it floats your boat to make the house super tight and then punch holes in it, why not?

    Hey Robert, what about my feelings - I'm sensitive ;-)

  54. Timmy O'Daniels | | #54

    Dynamic Breathing Building System, uses an insulating filter media in the envelope, coupled with the exhaust-only ventilation system that I've been advocating for years, to reclaim up to 100% of the outgoing heat while subjecting the incoming air to a higher degree of filtration than is possible with any other system.

    Robert,
    This sounds a most interesting technique.
    How is the insulating filter medium cleaned after it has been filtering for a while?

  55. John Brooks | | #55

    No one has answered the question about "WHERE" should the Air Barrier Assembly Leak Air?
    Do we need intentional openings in the Air Barrier Assembly?

    Should it leak under the rimjoist?
    How about providing a 1-1/2" wide Air Leak every 16 inches OC ?

    Or should it leak under the bottom plate?
    How about providing a 3-1/2" to 5-1/2" wide Air Leak under the bottom plate at every partition intersection?

    Is this the best place (or worst place) to concentrate the flow of air?
    Would this ensure the goal of at least 2 ACH50?

    What if we did the "Enhanced Goo as you Go ADA" ?
    Would the Enclosure still get enough breath? ;--)

    "Goo as you go" was discussed here
    http://www.greenbuildingadvisor.com/community/forum/energy-efficiency-and-durability/19107/airtightness-sans-sprayfoam

    Illustration by BSC... yellow marker by Lucas Durand

  56. Riversong | | #56

    The DBB Concept

    This project was launched in July 2006 to test and demonstrate the Energyflo™ cell - a new multi-functional component of the clean, low carbon Dynamic Breathing Building (DBB) systems of the future.

    Ventilation air enters the building pre-heated in winter and pre-cooled in summer, using the heating and cooling energy that would otherwise be lost through conduction and convection to atmosphere. At all times, air comes in filtered close to High Efficiency Particulate Air (HEPA) filtration standard.

    It is significant that a DBB system decouples energy use from the rate at which it is ventilated as a result of the intimate link that is created between building and environment. DBBs thus use less energy and at the same time provide high ventilation rates compared to modern, hermetically sealed buildings that seek to isolate the building from its environment. The benefits of DBBs also extend beyond their perimeters, since the air they exhaust is cleaner than that taken in. Over time, a DBB will clean-up the local ambient outdoor environment.

    Since a proportion of the exterior skin of the building is used as the ventilation source, the flow velocity through the intervening DI media required to deliver the number of fresh air changes per hour, or litres per second, is ultra low.

    In a loaded fibre filter the internal structure changes over time as branch-like dendrites form through the agglomeration of particles within the filter media. Some of these dendritic fibres themselves start to act as filter fibres, increasing the packing density. Since the collection efficiency in DI media increases with dendrite formation the risk of efficiency loss is eliminated.

    Correctly designed and implemented, the clogging rate of DI media can thus be slowed down to the point where it ceases to be of concern, even in the most heavily polluted urban and industrial environments, with no compromise in dynamic filtration efficiency or operation of the building. This is a significant finding that rivals in its importance the role of near-zero dynamic U-value in reducing the carbon footprint of the built environment, to sustain occupant health and enable clean indoor environments to be achieved at any location anywhere in the world.

    McLaren Community Leisure Centre, Callander Scotland

    This £3.2 million project features the use of healthy materials and a unique method of (pore) ventilation to create a fresh and healthy indoor environment which also saves energy, as part of the Scottish Sports Council's 'healthy buildings for healthy pursuits' policy.

    This project is the largest in the world to use dynamic insulation and the first to use it in a wet environment. Its application follows a number of years of research into moisture and air transfusive wall and ceiling systems by Gaia. This design involves drawing air into the building through the cellulose insulation effectively picking up the outgoing heat whilst also filtering the air. Lack of intake ductwork has health benefits and there is potential associated reduction in plant cost. The building was completed in 1998, and a monitoring programme is investigating the effectiveness of the system.

    The community sports facility in Callander, Scotland incorporates dynamically insulated squash courts, bowling hall, sports hall and a 20m swimming pool. Each has air introduced from pressurised ceiling voids through a dynamic insulation layer.

    It is the first major building in the UK to use dynamic insulation, and the first in the world to use the technique in a swimming pool environment.

  57. Riversong | | #57

    Lucas,

    I'm not suggesting deliberately leaving concentrated leakage points in the envelope - those are likely to result in concentrated moisture problems (unless exhaust ventilation runs 24/7). The deliberate "holes" are the passive make-up air inlets (preferably Airlet 100s) which, if located on more than one level of the house, can provide some minimal stack-effect air exchange when the fan is not running.

    The inlets, through their sealed metal duct sleeves, are non-destructive leak points that are not vulnerable to condensation (like all ducts, they should be sloped down and out), and they focus the air flow where it's most needed.

    The "goo as you go" method will never be perfect and will allow minor leakage under pressure at widely dispersed parts of the envelope, thus assisting in fresh air distribution when the house is under negative pressure. It's a reasonable technique that allows one to aim for a very high standard of tightness without going to ridiculous extremes.

    The only part of the ADA I'm not crazy about is the use of VOC-laden butyl rubber acoustic sealant, though I've never noticed any residual odor after completion (and I have a pretty sensitive nose). There are water-based acoustic caulks that I haven't tried, and there are EPDM gaskets specifically made for ADA.

  58. Lucas Durand - 7A | | #58

    Thanks Robert.
    I think you were answer John's question though ;-)
    I am still on the fence about how to ventilate.
    I think it would be great to achieve <1ach50 (though i won't go to extreme ends in the attempt) with breathing hole(s) sealed.
    With breathing hole(s) open, at least I know air exchange through the envelope has a very tiny "destructive" component.
    I think an advantage of the exhaust only system with passive air inlets that you sometimes advocate is that it is a distributed system and distributed systems are more resilient than centralized ones.

  59. Riversong | | #59

    Yup, that was John's question. I saw the "yellow marker by Lucas Durand" and assumed it was from you (did John pay you the license fee to use that illustration? - oops, forgot, everything posted here becomes the property of Taunton).

    Another passive possibility which I've never pursued is to pre-temper the incoming ventilation air through earth tubes. The idea has always intrigued me, particularly if there is an independent need for deep excavation or fill. But the challenge is to prevent moisture and mold in the sub-grade ducting (and, of course, keeping critters from crawling in).

    They're generally used only with underground or PAHS homes, and the diagrams I've seen typically show one large inlet and one large outlet.

    Another minor challenge would be to distribute the incoming ventilation air to each of the passive air inlets. This could be done with 4" ducts rising up in the middle of a double or truss wall envelope to pick up additional tempering from the house. A low air flow could be very close to room temperature by the time it enters the conditioned space.

    Just another take on the breathing wall approach.

  60. Lucas Durand - 7A | | #60

    Another passive possibility which I've never pursued is to pre-temper the incoming ventilation air through earth tubes. The idea has always intrigued me,...

    Ah, this approach has always intrigued me as well. It seems very straight-forward on the surface with only a few complications to work out - but the consquences of not working out the details could be serious.
    To beat the condensation/mold issue, I've seen where the builder installed the inlet pipe on an angle so that condensation drains to the outside. Not sure how that worked in the long-run.
    That is an interesting idea to split the inlet pipe and come up through the walls. I'm not sure it's ever been done that way. As you said, most pictures I've seen seem to suggest that PAHS dwellers don't mind getting their air from a single point source.

  61. Riversong | | #61

    PAHS dwellers don't mind getting their air from a single point source.

    Yup, they're pretty single-minded people ;-)

  62. Riversong | | #62

    In idea just came to me as I was pissing into my indoor wintertime urinal (a funnel on a garden hose which drops through the floor and spills out in the trees).

    When I was writing my earlier post about an earth tube air tempering system, I was falling into the techno-trap of imagining that only a tightly-fitted plastic conduit could keep the ground moisture out and minimize moisture issues.

    But that's back-assward thinking.

    One of the elements of the Bau Biologie approach is that building claddings should be somewhat absorbent to slow down the drainage flow during a rainstorm that is likely to find weaknesses and create leakage. Just like nature uses wetlands to buffer ground flows to prevent erosion and siltation, a "reservoir" cladding can be an asset rather than the liability that B.S. tends to consider it.

    Similarly, BB requires interior surfaces to be absorbent to buffer swings in RH. Mold growth, it has been shown, can occur even with controlled average indoor humidity during peak events like a shower, when surface humidity spikes. Once mold growth is initiated, then it can continue when the indoor RH returns to normal because of moisture stored in the mold organisms. An absorbent surface with absorbent layers behind it will prevent the surface humidity (equilibrium moisture content) from rising high enough to initiate mold growth.

    Following that principle, it's not a plastic earth tube that's needed but a clay pipe that can absorb excess humidity and prevent mold growth. Humidity, after all, is not the problem - it's mold and decay organisms that are encouraged by high surface or depth moisture content. And, if the clay pipe was made with lime, or otherwise alkaline, then mold (and even bacteria) cannot incubate on it.

    Old time farmers were much smarter about such things than modern building scientists. They routinely whitewashed their cow barns with lime to prevent mold and bacteria growth. For similar reasons, many natural builders use lime plasters or limewash as a finish. Lime over earthen (clay) plaster over hygroscopic walls. And clay offers the additional advantage of absorbing toxins and maintaining a high negative ion count (no wintertime SAD with lots of negative ions).

  63. Lucas Durand - 7A | | #63

    When I was writing my earlier post about an earth tube air tempering system, I was falling into the techno-trap of imagining that only a tightly-fitted plastic conduit could keep the ground moisture out and minimize moisture issues.

    I appreciate the subsequent body of your last post Robert, but did you also have an idea for an alternative to the tightly-fitted plastic conduit?

  64. Riversong | | #64

    Clay pipe. Spigot and socket joints with rubber seals.

  65. Lucas Durand - 7A | | #65

    Oh, sorry Robert. You did say that but somehow I missed it.

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