The science of building biology

In New Zealand, when designers and architects design our homes, we ‘like’ or ‘dislike’ their work.  Overseas however, if human health is negatively affected by a built environment that compromises natural biological functions, the building company, architect and manufacturers can be sued.

Litigation could result from an unhealthy indoor air climate and toxic levels of hazardous chemicals in the building or decorating materials, and from design errors leading to poor ventilation and the build-up of mould or excess humidity. This has led to countries such as Germany placing great emphasis on natural building and decorating materials, as well as on ‘building biology’ – the science of building natural, organic dwellings.

Compostable homes or chemical overload?

A hundred years ago our homes were basically biodegradable (with a few exceptions like lead paint). Humankind is part of nature but how often is this reflected in building projects?

Today, particularly in New Zealand, our homes are built with synthetic and partly toxic materials, lined with them, floored with them, and furnished and decorated with them. We contribute to toxicity in our homes during maintenance, repainting with chemicals, repolyurethaning furniture, benches, window frames, and more. Then we clean with additional chemicals. We defend ourselves with insecticides, walking our biologically vulnerable selves deeper into a synthetic, toxic world.

A jaw-dropping 80,000 new chemicals have been added to our choices since 1950 and are in common use worldwide. The demand for fast, cheaper building of houses after WWII opened the door for chemically ‘enhanced’ timber products, cladding, floorings, insulation, paints, glues and carpets.

The colourful new synthetic products were popular and affordable, but in the 1970s doctors began to see mysterious new respiratory, neurological, and immune system diseases. The science of building biology was born in Germany out of these observations and the research connected with them.

Toxic Materials

Susanne Brutscher of Greenhome Designs Ltd is one of several professional building biologists in New Zealand, and is also a professionally trained interior designer. She says New Zealanders regularly use timber treatments and floor coverings containing levels of formaldehyde that have long been categorised as toxic in Europe and America. Formaldehyde is also used in furniture glues, engineered flooring, and carpeting adhesives.

Synthetic building materials likely contain phenols, fire retardants, polyurethane, formaldehyde, volatile organic compounds (VOCs), and (polychlorinated biphenyls (PCBs). Engineered timber products such as MDF and plywood frequently contain preservatives, paints, glues, sealants, polystyrene, plastic, PVC, vinyl, epoxy and varnishes.

Brutscher says, “In conventional buildings the benefits of the ‘green’ materials you choose may be compromised by synthetic finishing touches, such as chemically enhanced furnishings, carpets, upholstery, mattresses, toxins in cleaning agents, lacquers, glues, food storage containers, and cosmetic products, and by moulds and fungi.”

Dust and heavy metals (aluminium, cadmium, lead and copper particles from computer fans, printers, street shoes, pets, fireplaces, and coloured inks on printed paper) are most prevalent on the floor, especially in carpets. Carpeting, including all-natural wool carpeting, has been proved to contain extraordinary amounts of accumulated toxins despite regular vacuuming. Children live closer to the floor than adults and are therefore more vulnerable to these toxins.

Stewardship for the whole life cycle of a product

Polyurethane eventually stops emitting toxins six months after application, but the important question for a building biologist is: what other chemicals in the environment can it react with? How many new compounds, the effects of which are completely unknown, are being created by combined exposure in a chemically saturated environment?

For instance, styrene is the extraordinarily toxic chemical used to make styrofoam (usually known in New Zealand as polystyrene), which is often added as insulation to homes. Once it’s no longer useful polystyrene has to go into landfill. It breaks down into compounds that act or react with other compounds around it. What will that reaction be? Certainly, broken down polystyrene compounds, including styrene, end up leaching into the soil and groundwater, and will eventually turn up in our water supply.

The afterlife of synthetic products in landfills is a serious problem.


It isn’t only chemicals making homes unhealthy. Most of us love our computers, TVs, electronic games, laptops, mobile phones, WIFI, smart meters and microwaves, all of which emit incompatible frequencies and create unnatural conditions for human biological systems. WIFI and electromagnetic build-up is an exceptionally inconvenient truth about your home. It can cause sleeping disorders, nervousness and headaches as well as electromagnetic-hypersensitivity, says Susanne.

As electrical beings emitting measurable electrical currents, our inbuilt personal electrical systems interact with the electrical currents around us. Our hearts operate at 50hz. Humans only function optimally under conditions which feature ion-healthy air such as in nature. Our systems register information electrically from air and soil. Reconnecting with nature, walking bare-foot, and gardening, all discharge surplus electrical charge into the soil. These activities have been used as ADHD therapy in the US for years.

Breathe easy

We have also enhanced the possibilities for toxic overload with the modern trend of hermetically sealing homes to exclude natural draughts, and thereby, fresh air circulation.

Humans breathe 11,000-17,000 litres of air per day. Natural air contains 21% oxygen but in airtight houses we re-breathe the air and available oxygen is reduced, resulting in tiredness, plummeting immunity, irritation, or even brain malfunction.

A sealed home is like living in a plastic bag. While the most expensive air conditioners ionise the air they circulate, for the most part reliance on electricity to supply air seems foolhardy given the occurrence of power outages. Wear a double layer of merino for warmth and open windows or doors for fresh air.

Greening your home

Specific indoor plants, including spider plants, Jade plants and Boston ferns, produce oxygen while absorbing certain toxic chemicals. In sufficient numbers, they help to literally ‘green’ a home.

Each home or office is different. There is no one-size-fits-all solution, but building biology principles can be applied wherever there are problems. Adding synthetic curtains to an old, airy home may not be much of a problem, but if you live in a hermetically sealed house and are experiencing health issues, then synthetic curtains will add to your problems.

Bringing more natural products into an existing home to balance the chemistry of the house may be cheaper than remediation, but it is far easier to incorporate building biology principles into the design from the outset.

Before 1960 homes may have been unhealthy because they were leaky or cold. Mould growth depends on humidity, air temperature, and lack of ventilation.There’s a difference between toxic and unhealthy. Mould is conditioned by humidity, air temperature, and lack of ventilation.

Common design errors can cause condensation and mould, and support high humidity levels. Such situations may be ‘healed’ by adding natural materials to counteract excessive humidity. Wood, mud, brick, and lime can regulate humidity by storing and releasing water to and from the air.

Some timber houses can develop mould because the maintenance, airing, or cleaning conditions are not optimal. Different remedial materials would be suggested in Northland than for a home in Central Otago where the natural conditions are quite dissimilar.

Go for natural

In greening your home, the best advice may be to eliminate as many synthetic household products as possible and to favour natural products.

Go with washable, easy-care natural floors such as wood or linoleum rather than carpets. Where washable floors are not ideal, opt for wool rugs rather than synthetic carpets. Oil wooden window frames, and sleep in metal free beds. Use latex mattresses or coconut fibre. Alternatives to petrochemically based paints are now readily available.

Use eco-friendly wool insulation – which often contains 5-10% synthetic material in order to stop it collapsing, but is still at least 90% better than a totally synthetic alternative. Use wooden furniture, or glass and steel, and upholster with natural fabrics such as organic cotton, hemp, bamboo, or coconut fibre.

Generally, any natural material can be used with a clear conscience to improve the health of your home. Search the internet for the many natural options that have become available in new Zealand as the demand for more natural living conditions has blossomed. It’s not just about our own health, although that’s important, but switching to natural lifestyles is also beneficial for the planet.

Beyond your home where they can contribute to toxic overload, in landfills the after-life of synthetic products is a serious problem for chemically manufactured building and interior decorating materials.

Best natural building and decorating materials

Timber, clay products, soft boards such as hemp and coconut fibre, limestone and lime plaster, glass, gypsum, hemp, steel, stone, cotton, linen, wool, leather, tiles, bamboo, cork, water, NZ-made good quality gib-board and magnesium board, cement plasters, and aerated concrete (too much can create an unhealthy home).

Useful references

About Building Biology –

Non-toxic Paint, oil, and varnish options –

26 Plants to detoxify your home –

Susanne Brutscher, Greenhome Designs Ltd –


Copyright Theresa Sjoquist 2017

First published in organic NZ Magazine (November-December, 2017)