by Dave Keenan, June 1997
last updated 5-Oct-199

[This contains the full list of about 24 errors and omissions that I referred to in my much shorter letter to the editor, ReNew #60, Jul-Sep 1997, page 10. The Healthy House is a book by Sydney and Joan Baggs, 1996.]

I must say that ReNew is the last place I expected to find a wholly favourable review of The Healthy House (ReNew #59, p52). I suppose it’s a little like writing staff references. No one wants to write (or publish) a bad one, so one has to look for what isn’t said, and read the subtle codes. I note that more than half the review was spent establishing the credentials of the authors rather than examining the content of the book. I intend to be a little less polite than your first reviewer. I guess this is more a critique than a review.

The aim of the book is certainly laudable and it does contain some reference material of great value to the ReNew reader, such as the directory of products and resources in Australia and New Zealand (among other countries). Other useful appendices contain sun position charts, lists of air & soil pollutants: problems and solutions, low allergy plants, poisonous plants, and bushfire resistant plants. The many beautiful colour photographs may be a useful source of ideas for house and landscape design.

In the introduction, the authors refer to Lovelock and Margulis’ Gaia hypothesis and suggest that we need to learn principles of "Gaian management" to become responsible "stewards" of nature. I wonder if they have read the last page of Gaia: the practical science of planetary medicine (Lovelock, 1991) where he specifically describes such thinking as a "dangerous illusion" and says that he would "sooner expect a goat to succeed as a gardener".

My major concern about The Healthy House is that, although the authors mention a distinction between what they call science, protoscience and parascience, but which some might call science, aesthetics and superstition, (or just science, poetry and wrong) they do not make it clear, throughout the book, which is which. This robs each of its unique contribution (to put it politely).

Another concern is, where the authors do give scientific information it is sprinkled with errors and omissions. They seem to have a particular problem with numbers. That is, when they use them for scientific purposes, as opposed to astrology, numerology or pyramidology.

One should expect architects to have a very good knowledge of three-dimensional geometry. So when the authors state (twice) that "any three-dimensional space can be filled, with no space left over, using any one of the Platonic solids", one starts to worry. The cube is the only Platonic solid with this property. Anyone can prove this for themselves by making enough of each shape out of appropriately cut and folded cardboard.

They claim that "the interior angles of any regular solid are equal to twice as many right angles as the figure has sides plus four right angles". This is quite wrong but some careful reading suggests that what they meant to say was "the sum of the interior angles of any regular polygon are equal to twice as many right angles as the figure has sides, minus four right angles".

It shows a certain carelessness with numbers when a scale of 1 inch to 1 mile is described as 1:63,366 and a map showing the strength of the earth’s magnetic field over its surface, has contours that suddenly jump up by a factor of ten from their neighbours (one too many zeros on the end?) and one contour line has two different numbers on it.

They don’t seem to understand the electromagnetic spectrum and the names given to the various parts of it. For example: "However we can also be affected by non-ionising radiation such as that from radio, television, microwaves (emitted by CB radios, electrical security systems, telephone relays, computer terminals, sonar and satellites) and by extremely low frequency (ELF) radiation which occurs around power lines." In fact CB radios do not emit microwaves and sonar does not use electromagnetic radiation at all. In general the book exaggerates the dangers (if indeed there are any) of non-ionising radiation, not to mention geomagnetic fields and some other scary things called ley lines and ch’i lines and lines of geopathic stress that only a dowser can find for you. Maybe ReNew should organise some independent geomantic surveys of a block of land to see how many dowsers agree with each other.

From a later section on Plant response to music and vibration: "Sound makes up a very limited band of frequencies in the electromagnetic radiation spectrum". Sound is of course not electromagnetic radiation at all, as anyone who has noticed the delay between a lightning flash and the corresponding thunderclap can tell you. Electromagnetic radiation can travel in a vacuum while sound can’t, etc. etc.

They claim that "noise attenuation depends only on the density and mass of the intervening material between the noise and you". They apparently have no understanding of the other parts of the acoustic equation, namely compliance and damping.

Radiant heat intensity is not "directly dependent on the distance from the flame", as they claim. It is dependent on the square of the distance. But at least they got the numbers right in the example.

They state, "In the southern hemisphere, northern and eastern slopes (southern and western slopes in the northern hemisphere) are more exposed to the extremes of the sun". I think this should have read "and western" in both cases. You swap north for south but not east for west when changing hemispheres. The sun still rises in the east and sets in the west.

They tell you that you can find true north simply by putting a stick in the ground so it casts a shadow. They claim that the shadow’s direction will be true north. There is no mention that the stick needs to be vertical, that you have to do it at solar noon, that it only points north in the northern hemisphere, that if you are in the tropics you need to take account of the time of year, and that in the tropics there may not be any shadow at all.

The section on feng shui leaves me speechless with its non-sense. I’m willing to accept that feng shui may embody some useful aesthetic rules, but doesn’t designing a house based on the birth date of the ‘principal occupant’ sound just a little ridiculous to you.

The authors admit that feng shui practitioners cannot agree amongst themselves, when adapting the rules to the southern hemisphere, whether or not to exchange north for south so as to maintain solar access. They conclude that despite "the conflicting requirements of solar orientation and traditional feng shui principles, it is clear that those principles should be followed without alteration". "We should ignore the exhortations of those who argue that inversion is necessary in order for the building to have adequate solar access".

For me, with those sentences, the authors lost all credibility. Note that this conflict does not occur in the northern hemisphere, and if all references to the sun in feng shui are retained for the southern hemisphere (i.e. north is inverted for south) this produces "strange, even ridiculous, results". So why not conclude that feng shui simply doesn’t work in the Southern Hemisphere rather than reject solar orientation principles, which are common sense to anyone familiar with how the sun moves through the sky? And then there’s the section on the importance of choosing the right street number for your house. Gimme a break!

We are told that the human body "has a strong electric field of some 10 million volts per metre". I think that if my body had such a field across any millimetre of it I’d know about it. Of course if it were across the whole length or width of my body I wouldn’t know about it, I’d be dead, fried to a crisp.

The section on ‘the effect of temperature and humidity on health and comfort’ contains some dubious statements regarding humidity and fails to mention the effect of outdoor temperature and acclimatisation on the comfort temperature range.

Regarding sewage and wastewater, they claim "once the waste is engulfed by water, the breakdown process ceases. Oxygen, chemicals and mechanical systems must then be used. This requires an immense infrastructure and water-storage systems, with all their attendant construction and maintenance costs." Firstly, the breakdown process does not cease, it slows, but more importantly the anaerobic bacteria involved may break down things that aerobic bacteria cannot, and vice versa. Secondly, the "septic" tank need only be followed by a simple (but large) aerobic sand filter, which the authors have apparently never heard of. I have one under the lawn in my backyard, you wouldn’t even know it was there. They then sing the praises of dry composting toilets. In my opinion these are not ready for urban areas or in-house use because of the problem of insects escaping via the pedestal. I had one for several years and tried everything before giving up and switching to a low flush with septic tank, aerobic sand filter and planted ponds. See The Trouble with Composting Toilets.

Regarding soap and detergent they say, "It is far better to use plain soap - you will have no problems using your grey water". In fact soap can still cause salination problems since it contains sodium. The class of detergents called alkyl polyglucosides are readily biodegradable and contain only carbon, hydrogen and oxygen, so when broken down aerobically they leave only carbon dioxide and water, no toxins and no nutrients. This is ideal for grey water systems, far better than soap. Unfortunately they are only about as effective as soap in their cleaning power and commercially they only appear as one component of some dish washing liquids.

They state that "Solar hot water systems can deliver water at temperatures of up to 50°C." I don’t know about theirs but mine can get up to 99°C, which is why I have a tempering valve feeding all but the laundry taps (to reduce it to a safer 50°C). Also, "They use the infra-red radiation of the sun to provide hot water for washing and bathing". This is a common misconception. In fact the infrared provides only about half the energy to heat the water. The other half is provided by the visible radiation or "light".

Regarding alternative energy systems they claim that "All electrical equipment in the house has to be converted to run on a 12, 30 or 110 volt supply, depending on the storage battery". Inverters do eventually get a mention. Apparently you connect them directly to your PV modules. In recommending tilt angles for PV modules they make no mention of the different requirements of winter-peaking versus summer-peaking loads.

In case anyone cares there is a way of wiring two-way light switches that eliminates large area current loops and the resulting magnetic field. It just uses twice as much cable. Contact me if you really want to know.

Regarding insulation, they state that reflective foil laminates are unacceptable because they are impermeable. In fact permeable (finely perforated) foil laminates are readily available. They list R-values for common materials as if it is simply a property of the material. They don’t mention thickness. They also don’t mention the need for air gaps in conjunction with foil laminates.

Regarding fireproofing of cellulose insulation, they claim that Borax and Boric acid are "benign, almost as safe to ingest as common house salt". This is irresponsible. My copy of Safer Pest Control (Rogers, 1986) gives lethal doses for humans as follows: Common Salt 4000 mg per kg body weight, Borax and Boric acid 709 mg per kg body weight; nearly 6 times as toxic. Single doses of 18 to 20 grams in adults, and 5 to 6 grams in children, have been lethal. Still, this is low toxicity compared to most insecticides and it’s quite safe as long as it stays in your ceiling.

Regarding termite control, they say "Chlorpyrifos is a synthetic pyrethroid and probably the least hazardous of the organophosphates". Neither Safer Pest Control nor Building Out Termites (Verkerk, 1990) consider chlorpyrifos to be a pyrethroid of any kind. It is however an organophosphate. They claim that arsenic trioxide "can be used as a barrier to termites". This is absolutely and dangerously wrong. It can only be used in tiny amounts to destroy existing colonies (Verkerk, 1990) it is far too toxic to all living things to be used as a barrier.

In stating the Second Law of Thermodynamics (that entropy (disorder) always increases), they omit the important proviso that it applies only to processes in closed systems, i.e. systems where energy is conserved. They also say "This heat loss was first termed entropy in 1850 by the German physicist, Arthur Eddington". First, entropy is not heat loss, and second, German? With a name like that? He was in fact Sir Arthur Eddington and yes, you guessed it, he was British. And did you know that "Every item that human beings have ever made has added to the total heat stored by the planet." So how come this gets stored but the far greater amount of energy arriving from the sun every day gets radiated back into space? If only we could find where it’s stored.

According to the authors "the Gaian way of life is based on placing the needs of the Earth organism first and humanity second". Now I don’t necessarily disagree with this statement but they fail to draw the obvious conclusion. Every good Gaian who cannot reduce their entropy production to zero should commit suicide as soon as possible, in a non-polluting manner of course.

Instead, how about we just recognise that we have the same right to exist as any other species (not less) and that our survival is dependent on the health of Gaia and hence the other species. Enlightened self-interest, I’m all for it. It’s just the enlightenment part that’s difficult, and it certainly won’t be helped by books that treat superstitions as if they have the same value as science.