Basically, a non-toxic home is a home free of chemical pollutants as well as natural pollutants such as dust, mold spores, and pollen. Most people would assume that their homes are already free of pollution. It's not something normally associated with the indoors. But in reality the average home interior is more polluted than the outdoors of even urban areas. The reasons for this are many but relate primarily to what homes are built from and decorated with and how they are heated. After WWII the building materials industry began to make increasing use of the products of the petrochemical industry for two reasons; the steadily deteriorating quality of natural lumber and a desire to reduce construction times and thus labor costs. Chemical treatments boosted the resistance of lumber to weathering and insect damage and allowed the use of less seasoned wood, speeding up production. Using laminates -glues- allowed lumber of inferior qaulity to still be put to good use in new large area sheet forms that reduced assembly labor -plywood and chip-board. Similarly, laminates of paper and gypsum in the form of 'drywall' or 'sheet-rock' replaced the labor intensive process of finishing stick-built walls with wooden lathing strips and troweled plaster and made decoration and renovation easier. Laminates also featured in new forms of wallpaper made of new synthetic fibers and sheet polymers offering vibrant colors, easier application, and greater durability and water resistance. New rubber-like adhesive caulks afforded better sealing and jointing, compensating for less skilled carpentry and reducing drafts and leaks. New paints and varnishes with sophisticated polymer chemistry offered more vibrant colors, more resilient surfaces, fewer fasster drying coats to apply, easier cleaning, and much greater resistance to weather. New industrial materials were also introduced for insulation offer greater thermal performance and a host of new synthetic fibers found their way into cheap resilient carpeting that made the luxury of wall-to-wall carpeting in an endless variety of colors, patterns, and affordable to all.

But these improvements came at the hidden cost of introducing a witches brew of chemicals into the home environment. Most products of polymer chemistry have a common characteristic. They are mixtures of organic compounds which shift between states of liquid and solid/semi-solid with the evaporation of a solvent. Most of these solvents are what are known as Volatile Organic Chemicals -'volatile' because they shift from a liquid to a vapor phase at a relatively low temperature. They are things like alcohol which, as most people have experienced, quickly evaporates at room temperature, causing the cooling effect associated with rubbing alcohol when its placed on the skin. There are many different solvents contained in modern building materials and they aren't all depleted from the materials that contain them very rapidly. Many slowly leak into the air over spans of years or even decades. This is not always unintended. The latent presence of solvents keeps certain polymers in a perpetually soft flexible state. In addition to solvents, there are also VOCs that are deliberately intended to be around for a long time because of the job they do -fiber penetrating preservative, pesticides, anti-fungal agents, and stain inhibiting agents in particular. These are oil-like chemicals intended to remain soaked in the fiber matrix of wood, paper, or fiberous materials indefinitely. Yet they can still become volatile, exuding fumes. Almost all of these VOCs are latently toxic. For the healthy person they might not cause immediate harm unless present in very large amounts but for the EI they can cause severe illness in the tiniest amounts.

In addition to introducing VOCs, many of these new building products changed the ecology of the home, eliminating havens for some pests while creating new havens for others. Homes became more impermeable, creating pockets of moisture while new materials like paper laminate dry-wall and drop ceiling tiles created good sources of food and shelter for fungus. Toxic fungus contamination has become a popular subject in the news and the root of this problem is that laminate materials like dry-wall and plywood provide both food for fungus and shelter from any outside-applied anti-fungal agents. Once it's in these materials you cannot do anything about it but tear the structure down and destroy it.

Another common source of indoor pollution is the technology used for heating and cooling homes. Again, after WWII trends in housing technology shifted in favor of the use of forced air heating systems based on oil and natural gas furnaces. We all know that the by-products of combustion are the source of pollution from automobiles but this also applies to any device which burns hydrocarbon fuels. Without absolutely perfect containment, pollution from both combustion and the leakage of fuel from furnace systems will permeate the home. The same is true from gas powered water heaters, washign machines, and kitchen ranges and ovens. Not only is this pollution a latent hazard in and of itself, it encourages the growth of fungus which is further supported by the use of forced air ductwork. It is difficult to the point of futility to truly maintain clean conditions in conventional heating and cooling ductwork and thus build-up of dust, fungus, and sometimes disease-causing bacteria is a common problem. This became apparent with the dramatic Legionnaire's Disease outbreak of the late 1970s, followed by many cases of Sick Building Syndrome in the 1980s and 90s.

Because these latently toxic materials and technologies have become ubiquitous in contemporary construction, with builders largely ignorant of their nature because their manufacturers are not required by law in many countries to fully disclose it, (the US being one of the worst in this respect) it is a very great challenge to avoid them. It is not a question of employing any special technology or unconventional architecture. It can be as straightforward as building in the way people did before these things were introduced and/or using newer materials and technologies which offer less toxic alternatives.

Long before EI became a global public health issue, there were a few people questioning the long term safety of the newer building materials. Notable among them is Prof. Dr. Anton Schneider who began studying the relationship between architecture and health in Germany in the 1960s and in 1975 established the Institut für Baubiologie. (www.baubiologie.com) The word Baubiologie means Building Biology and relates to the idea that a building is akin to an organism whose own health impacts and influences the health of its occupants and the natural environment around it. Schneider established the following 25 Principles of Baubiologie which have become inspiration to a community of architects and 'green' building advocates around the globe;

1 A building site shall be geologically undisturbed.

2 Residential homes are best located away from industrial centers and main traffic routes.

3 Housing shall be developed in a decentralized and loose manner interlaced with sufficient green space.

4 Housing and developments shall be personalized, in harmony with nature, fit for human habitation and family oriented.

5 Natural and unadulterated building materials shall be used.

6 Walls, floors and ceilings shall be diffusible and hygroscopic.

7 Indoor air humidity shall be regulated naturally.

8 Air pollutants need to be filtered and neutralized.

9 An appropriate balance of thermal insulation and heat retention is needed.

10 The air and surface temperatures of a given room need to be optimized.

11 A heating system shall feature radiant heat using as much (passive) solar heat as possible.

12 The total moisture content of a new building shall be low and dry out quickly.

13 A building shall have a pleasant or neutral smell. No toxins shall outgas.

14 Light, lighting and color shall be in accord with natural conditions.

15 Protective measures against noise pollution as well as infrasonic and ultrasonic vibrations need to be human oriented.

16 Only building materials with little or preferably no radioactivity shall be used.

17 The natural balance of atmospheric electricity and ion concentration shall be maintained.

18 The Earths natural magnetic field shall not be altered or distorted.

19 Man-made electromagnetic radiation shall be eliminated (or reduced as much as possible).

20 Cosmic and terrestrial radiation is essential and shall be interfered with as little as possible.

21 Interior and furniture design shall be based on physiological findings.

22 Harmonic measures, proportions and shapes need to be taken into consideration.

23 The production, installation and disposal of building materials shall not contribute to environmental pollution and high energy costs.

24 Building activities shall not contribute to the exploitation of non-renewable and rare resources.

25 Building activities shall not cause a rise in social and medical costs.

These principles have come to be adopted as general rules of thumb for non-toxic housing, though some have little relevance to the individual EI, others have greater or lesser priority relative to cost and individual sensitivities, and some may be considered somewhat speculative from the standpoint of formal public health science due to a paucity of supporting clinical research documenting their supposed health impact. These principles are relatively straightforward but it's easy to see that most of them pertain to things the average building contractor or real estate developer has never had to consider -and probably never will in the absence of government legislation requiring them to. Consequently, finding pre-existing housing that meets these criteria is virtually impossible in most industrialized countries and finding contractors with the necessary knowledge and skill to build such housing difficult, to say the least. As a result, building homes that conform to these principles using conventional construction methods is an expensive and frustrating process that no one limited to the fixed income of government assistance for the disabled can even hope to accomplish. This has compelled many EIs -this author in particular- to explore the realm of alternative architecture, seeking novel building technologies that can offer the potential to meet these criteria with less cost and hassle -indeed, at a cost far lower than average even for mainstream housing.

I have adopted a simpler criteria based on the higher priority of material composition in respect to the sensitivities of the average EI and the more critical aspect of affordability for people with severely limited income coupled to draconian government restrictions on its use. It has occurred to me that the cost and difficulty in realizing a non-toxic dwelling is proportional to the complexity of the structure and the diversity of its materials. In other words, homes become cheaper to build when they are simpler in design and composition and, by extension, the management of their potential latent toxicity is easier when there are fewer different materials to account for. Conventional home construction suffers from a reliance on a rich mix of materials which tend to require much hand labor to craft and assemble and which tend to be more difficult to secure in non-toxic forms because, being subject to mainstream use, they've suffered the most 'improvement' by the chemical industry. The obvious strategy, therefore, is to look at types of construction where as few natural or chemically unadulterated materials as possible do as many jobs as possible. In addition to simplicity in composition, so too should there be simplicity in design because an uncluttered living environment lends itself to efficiency of space and economy of materials and labor. Thus I have favored the approach of open layout designs with integrated furnishings, minimizing the number of rooms and therefore further the amount of finishing work. This is particularly practical for EIs, many of whom are compelled to live a solitary lifestyle anyway and have little need for the redundant privacy afforded by many small rooms. Following this simpler strategy, one tends to realize many of the traditional Baubiological ideals as a natural consequence of using simpler materials and lighter and simpler design. The challenge, of course, is to put this to practice, and that is the subject of this journal.

A structure with a non-toxic composition is not by itself sufficient to make a non-toxic home. Its surrounding environment must likewise be non-toxic, free of the many sources of pollution common to urban and suburban communities. This presents a great complication to the search for non-toxic housing for many EIs because, while it is a relatively straightforward task to make a building itself non-toxic, the outside environment is impossible to effectively control, especially in a civilization with such insidiously pervasive pollution and casual indifference towards it on the part of the public. This results in many EIs being forced to wander from place to place for extended periods of time in search of just the right situation because, even when they do find homes which are or can be renovated to become non-toxic, the location of those homes may be intolerable. We normally associate pollution with large industry and, while this is a significant source of pollution, it is relatively minor in terms of volume and pervasiveness to the pollution produced by homes, automobiles, and municipal power facilities. This is pollution most people are quite oblivious to even though it has the most direct impact on their health. I have always puzzled over environmentalists fixation on large corporations when it's the general public who are, by far, the worst environmental offenders.

Not surprisingly, most EIs seek out generous parcels of land on the fringes of civilization, in areas on the edge of wilderness where neighbors are few, traffic sparse, and obstruction by building codes minimal. But such locations are challenging due to the lack of municipal infrastructure, medical services, and the simple loneliness or remoteness. Furthermore, it can be difficult to get viable information on locations, and thus determine their suitability, without being able to go there and examine them first-hand. This is a big problem for people in poor health and for whom travel is a grueling experience. Thus EIs have tended to congregate in various small communities where word of mouth has spread about safe environmental havens, or just the successful habitation of a few other EIs. It is not unusual for these to spring up in some proximity of specialized health care. For instance, some of the first EI communities appeared in Texas in proximity to the US's first and largest Clinical Ecology clinic, though today Texas has become less popular a haven due to its steady decline in pollution standards and a history of violence targeted specifically at EIs. One of the most notable EI communities today is in Snowflake Arizona, the only community in the US to actually zone for EI-specific residence.

Most EIs suffer from a sensitivity to climactic extremes and thus seek out locations in regions offering a mild year-round climate. but finding a clean environment combined with a mild climate is quite a challenge today as any place with mild climate has a tendency to attract the most residential or tourist development. In the US, the Southwestern states have been the most popular destination for EIs. In fact, Arizona is the only state in the union where a town has specifically zoned for EI residence, imposing restrictions on development that might effect the health of its EI residents. This is not surprising considering that the region already has a long history as a health haven going back to the beginning of the 20th century, many of its now cities founded as sanctuaries and sanitoriums for people with respiratory ailments. But time is running out for the region as it is the fastest growing in the US, its desert environment no longer a barrier to development as it once was.