BuildingHealth & Disease

Building Biology – The Third Skin

Extracted from: ‘Third Skin’ A. Vasella, Dip Arch., P.I.J. #14. ‘Biotechture’ S.Lesiuk, P.I.J.#8. ‘Biotectual Systems’ R. Doernach P.I.J. #7. International Institute for Building Biology and Ecology PO Box 387 Clearwater FL 34615 USA.

Edited by Alanna Moore

In the western, urban world the average person spends around 90% of their time indoors. Evidence is mounting to show that such prolonged exposure to modern building materials and architecture can be detrimental to health. There is now a growing ‘bio-house’ movement where only natural and renewable resources are used in building people friendly homes.

Biological architecture, originating from the German ‘baubiologie’ movement, addresses the ecological nature of building and the integral relationships between people and their built environment. Building biology makes for good preventative medicine. It aims to re-establish the lost balance between technology, culture and biology. The three should play an equal role in the building activity.

The Third Skin

In building biology the building is considered as an organism. In this analogy the walls are seen as a third skin (our clothes being our second skin). The function of skin is to breathe, evaporate, absorb, protect, insulate and regulate air, moisture and pollutants. It is an open system with constant exchange between inside and out. Modern buildings often have a closed system, and are sealed tight (‘super-insulated’), with damp proof courses and the like. This can lead to a build up in radioactive radon gas in some places (a big problem in the USA), and may reduce the benefits of passive solar energy in spring and autumn.

If a building is insulated then this needs to be combined with good ventilation. Without regular air renewal, a comfortable and healthy climate is impossible, with pollutants such as chemical fumes, bacteria, mould and positive ions accumulating indoors. Air conditioning has similar detrimental effects.

Hazardous materials

A common hazard in the modern home comes from toxic fumes, especially formaldehyde outgassing from synthetics such as paints, varnishes, glues, textiles, furniture, foam rubber and chipboard. This creates a fire danger and toxic effects in people which can lead to allergies and other problems. Some building materials are actually radioactive in varying degrees. Concrete homes are unhealthy when freshly built due to the high moisture content and will not be fully cured for between 3 and 5 years. Many homes built in the 1960s in Australia were constructed from asbestos cement, a carcinogen when the fibres are exposed and breathed in. Lead, although now banned due to high toxicity, may still be lurking in the plumbing and paintwork of old homes.

Environmental costs

The modern building industry rarely counts the cost to the environment of extracting materials but this too is addressed in building biology. High energy inputs from non-renewable resources and the polluting and energy consuming transportation of materials over long distances is best avoided. Brick homes, for instance, may be snug but there is a high initial energy use to kiln dry them.

Building ‘diseases’

There are four main areas for concern in the ‘sick building syndrome’.

  • Chemical disease. As already mentioned, synthetic materials outgas dangerous fumes.
  • Electrical diseases. Electrostress is a syndrome caused by the 50Hz frequency electromagnetic fields generated by appliances and wiring. The human body is sensitive to electrical influences, so power points and appliances should be distanced from sleeping places (over one metre). Another solution is to install a central switch in the meter box which turns off whole circuits when they’re not in use. Other forms of radiation generated by TVs, radios and computers should be avoided as much as possible. Electrostatic charges which may be generated by synthetic materials and other sources can also accumulate with adverse effects.
  • Cage diseases. Concrete and steel buildings can create a Faraday Cage effect, that is, natural radiations which help regulate life systems are screened off or disturbed.
  • Location disease. Geobiology, concerning natural radiations that originate within the Earth, is a new science based upon traditional knowledge. In earlier times new home sites were surveyed by dowsing techniques before construction began. This was deemed necessary as the consequences of building over underground streams or geological faults was believed to lead to chronic disease such as cancer.

Construction of timber and mud are generally considered best. Wood has the capacity to absorb dust and neutralize bad odours. It regulates air humidity and therefore should be left as natural as possible and only protected with a thin layer of linseed oil, bees wax or some of the modern healthy products now available.

Mud brick is probably the most ecologically friendly material, being fully recyclable and using minimum energy. It fulfils most of the desired skin functions and has excellent heat storing capacity. One drawback is its bad insulation properties and it must be protected from humidity.

Other materials suitable for the healthy home are cork, wool, sisal and coconut fibres. These all have the ability to exchange humidity, heat and fresh air, whilst maintaining the proper ion levels for human comfort (we thrive in a 60:40 negative to positive ion ratio).

If heating is required then radiant heat is the ideal form. The traditional German Kachelofen is a masonry and tile wood or gas burning radiant heater of high efficiency and benefit.

Avoid furniture with synthetic components. Ergonomic designs are best for comfort and health.

Building biology deals not just with building materials and their influence on the human body but also with the environment in general and the climate of living. This climate of living is determined by a number of factors:

  • installations and furnishings
  • noise and acoustics
  • lighting, colours
  • radiation, avoiding disturbed areas
  • radioactivity
  • space, form and proportion
  • physiology and psychology of living and working
  • city planning, with biological, ecological and sociological aspects.

The Bio-house

Bio-houses and bio-settlements have been sprouting all over Germany in recent years. Made from natural materials, bio-houses often contain solar temperature-control systems or insulated winter gardens for heating. Sites are surveyed with divining rods to ensure the area is free of ground water veins and other electromagnetic disturbances.

Bio-houses are the most complex of ecologically sound products burgeoning on the German market as the public’s awareness of environmental concerns grows. In 1989 it was estimated that between 5 and 10% of all houses being built in Germany were bio-houses, and that another 25% contained some elements of bioconstruction.

A new breed of designer also has evolved – the bio-architect, now represented by the Federation of Architects and Biological Building. The Institute for Biological Building in Rosenheim was founded in 1982, training architects and offering construction workers courses in bio-building methods. The bio-house phenomena has expanded to include bio-settlements, that is communal bio-housing projects. Source: Newsweek 21/8/89

Biotechture

The urban environment dramatically alters the microclimate of an area. The rock-like surfaces of concrete, asphalt and brick conduct heat and retain heat rapidly. Streets, walls and roofs also form a maze of reflecting and absorbing surfaces which capture heat. Rainfall is removed by gutters, drains and stormwater pipes, robbing the soil of water so that yet another cooling mechanism is lost.

Vegetation however can be used to reverse these processes.

The covering of facades with a carpet of vegetation cools in summer and insulates in winter, whilst refreshing the spirit. Plants usually intercept between 70% and 90% of incoming solar radiation. Deciduous trees and vines can provide the advantage of perhaps 5 degrees C heat reduction in summer, whilst in winter allowing sun to heat the home, reducing energy loss by as much as 30%.

Selection can be made from complete of incomplete canopied species; from different types of leaf distribution (from vertically hanging to horizontal leaves) and from different species’ transpiration capacities.

Transpiration converts water in the canopy leaves from liquid to gas; water vapour then passes from the leaf into the surrounding atmosphere, having a cooling effect. Plants with a low transpiration rate are generally drought tolerant species, usually having small, leathery, hairy or waxy type leaves.

Climbing plants growing directly in the Earth offer the most promising results. They can either cling directly to the wall of the building or be kept a distance with a supporting structure. In many cases growth of up to 60 and 70 years directly on walls has protected rendering rather than damaged it. Nevertheless there are cases of rendering sustaining damage in exposed positions and for this reason a light supporting structure is recommended.

A timber lattice mounted on wooden posts and stretching from roof to ground could be built. Alternatively polypropylene ropes anchored in the ground could be stretched to the roof with horizontal ropes woven through, and tensioners to minimize wind noise.

In summer, evergreen leaves raise themselves towards the high angle of the sun, thereby operating as a ‘ventilation blind’. The chimney effect of vegetation on a wall thus cools the building and may even generate breezes. In winter the leaves of evergreens lower their inclination on accordance with the lower sun angle and he overlapping leaf effect forms an insulating layer of still air around buildings.

North facing walls (southern hemisphere) would suit fruiting and deciduous species of vine, whilst the other aspects would be more suited to evergreens.

Large leaved evergreens dissipate airborne noise pollution, especially at the critical high frequencies. Plants are efficient air cleaners, causing dust and airborne viruses to deposit. There are many benefits to growing your own home!

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