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Green Architecture avoids the use of polluting materials and activities. This minimizes the global and localized risks to planetary systems such as air, land, and water as well as minimizing the potential health risks for the users of buildings, the construction workers and the people involved in the production of materials.

 

Some of these issues are discussed below:

• Global Warming 

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With buildings presently responsible for approximately 50% of the planet’s greenhouse gases and as discussed with the chapter on Energy, those involved in the building trade have a major part to play in averting the catastrophes of global warming. Building construction and design can significantly reduce the emissions of principal greenhouse gases like Carbon dioxide (C02), CFC’s, and HCFC’s.

Furthermore, by protecting and increasing the sinks for greenhouse gases the building trade has a further responsibility to the health of planetary systems. This is achieved by:

• Using alternatives to non-renewable tropical hardwoods so as to prevent the destruction of rain forests. Trees and forests act as great carbon sinks and are the lungs and rainmakers of our planetary systems.

• Protecting and increasing the overall coverage of vegetation on a given site, by giving space for planting in, around, against the sides of, and on top of buildings.

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• Ozone Depletion & CFC’s

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The present destruction of the ozone layer is well documented. It is the cause of increasing levels of harmful U-V rays, threatening the health of both humans and the environment at large, with the potential for devastating results. At very least 50% of the use of ozonedepleting substances – CFC’s (chlorofluorocarbons), HCFC’s (hydrochlorofluorocarbons) and halons - are associated with the building industry. (Ref: 7)

The main measures that one can take to help phase out their use in the building industry include:

• ​Design buildings which avoid air-conditioning systems. Avoid the usual deep plan office so as to maximize natural light and ventilation.

• Avoid specifying materials, which utilize CFC or HCFC in their production, commonly being plastic foamed materials such as insulation boards, jointing and filler products. These include:

> Expanded extruded polystyrenes

> Polyisocyanurates

> Polurethanes

> Phenolics

• Avoid specifying halon-based fire extinguishers.

• Upgrade existing air-conditioning systems that use CFC’s. Avoid the release of old refrigerants into the atmosphere as well as the repeated use of CFC-related materials including HCFC’s.

• Certain chlorine-based solvents - being ozone-damaging substances - are also to be avoided.

• Take especial care when dealing with:

Refrigerants:

Air conditioning systems and refrigeration systems once commonly used CFC’s as their refrigerant and can still be found with most old systems. Do not be easily duped by sales persons claiming to sell supposedly cleaner CFC-free fridges or air-conditioning systems. Many have simply been replaced with HCFC’s, which although less damaging to the ozone layer, is still an ozone-depleting substance. Furthermore, as is the case with many new fridges, while they may have replaced the CFC or HCFC refrigerant, one often finds that the products are lined with a high-density foamed insulation material that has been manufactured with the use of CFC’s.

 

Plastic Foamed Products:

Extremely careful scrutiny is necessary when considering specifying products which have involved the use of a blowing agent, like plastic foamed products – insulation boards, pipe and geyser lagging, refrigeration plant insulation etc. For example, when dealing with Sagex - a major producer of plastic foamed insulation products – the sales representative claimed that ozone destruction was no longer a problem, as their polystyrene products were no longer made with CFC’s, and displayed the ozone friendly labels. However when one looked at their complete range of products it became apparent that their pipe and geyser-lagging - a closed cell, phenolic insulating foam “Megaphen” - which they advertise as “non-toxic”, did not bear the ozone-friendly label. This was because they are still using CFC’s as the blowing agent for this product.

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• Trace Organics

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Substances, which have become known as trace organics, cover a wide range of carbon based structures and are causing wide concern related to their rising pollution with indoor air, as well as our supplies of water and food. A large number of such substances are cumulative in the body; some are carcinogenic and others cause damage to the liver and kidneys. In our present context the building industry is contributing heavily to the accumulation of these substances in the environment. In particular, all materials that contain solvents and preservatives are of concern.

 

Organic Solvents (non-water based) Being dangerous to humans and the environment at large, the use of organic solvents is best avoided. Their use presents potential health problems for factory and construction workers as well as the inhabitants of the buildings that the solvent-containing materials end up polluting. Being volatile substances, which are unstable at room temperatures, (otherwise known as volatile organic compounds or VOC’s), they will off-gas, and as such will present problems with indoor air pollution. This is especially so with newly formed materials, where the levels of off-gassing is higher. These solvents are found in a wide range of common building products:

> Paints, especially non water-based enamels but including the emulsion-based acrylics.

> Adhesives used by the carpeting and tiling trades. 

> Adhesives & glues used by the joinery trades for the laminating of veneers, counter tops, etc.

> Certain laminated timber products, shutter boards, plywoods, blockboards and laminated timbers             sometimes make use of an oil based benzene (organic solvent).

> Certain wood treatment processes require the use of a solvent carrier i.e. PCP (Pentachlorophenol)             TBTO / Lindane (Mix of Tributyl Tin Oxide & Gamma Benzine Hexachloride)​

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• Sick Building Syndrome

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Unhealthy, polluting or toxic building materials and building systems, are causing what has commonly become known as sick building syndrome (SBS), which is now considered one of the major threats to public health. Indoor air pollution is a major cause of SBS and modern scientific research has indicated that in certain cases, the indoor environment may be as much as 10 times more polluted than the outdoor environment. (Ref: 8) Other causes of SBS include eyestrain, noise pollution, the excess build-ups of static charges, and adverse geomagnetic and electro-magnetic fields. Common symptoms of SBS include: allergies, asthma, eye, nose and throat irritations, fatigue, headaches, nervous-system disorders, respiratory congestion, sinus congestion, yuppie flue and cancer. Both worker’s health and their levels of productivity are directly related to the health of a building and it’s materials.

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• Indoor Air Pollution

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The US Environmental Protection Agency considers indoor air pollution to be one of the top five threats to public health. (Ref: 9.) With many people spending up to 90% of their time indoors, the long-term exposure to off-gassing chemical vapours has caused a dramatic increase in the numbers of cases of allergies, chest related illnesses chemical hypersensitivity and cancer. Furthermore, the occupational hazards for construction workers and factory workers dealing with such materials are a peril to their health and safety. While the health hazards of asbestos are now widely accepted, concerns over a much wider range of substances have become evident. A pollutant such as formaldehyde is a toxic off-gassing volatile organic substance (VOC) and a known carcinogen. It is commonly found in regular building materials like:

• Paints

• Synthetic carpets and carpet backings.

• Tiling and carpeting adhesives.

• Chipboards, shutterboards, plywoods, blockboards, superwood and other pressed wood products. By far the most hazardous of these being chipboard and superwood.

• Insulation foams.

• Foamed products such as those used in upholstery and foam mattresses

• Other potentially harmful toxins, which pollute indoor air sources, are commonly found in: o Asbestos. Note that it is more dangerous to remove asbestos materials than to leave them place.

o Synthetic materials that release hundreds of volatile organic chemicals into the air.

o Paints. 18 o Electronic devices, which emit a variety organic compounds.

o Toxic Wood preservatives.

o Anything which uses a non-water based solvent; such as resins, epoxy’s, polyurethane, adhesives and many types of timber treatments.​

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• Safeguards to Indoor Air Pollution

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The main safeguards against materials leaching out chemical gases to pollute the indoor air are:​

 

• Avoid the use of potentially polluting materials altogether by constructing, finishing and furnishing with natural rather than man-made materials. 

• Use non-toxic or low-emission, building materials and furnishings. Ask suppliers for a Safety Data Sheet of intended products, and avoid products with organic solvents, formaldehyde’s, and other VOC’s and harmful chemicals. 

• Specify water-based, solvent free materials and advise that maintenance staff avoid using solvent-based cleaning agents. 

• Avoid the design of deep plan types of buildings that are heavily reliant on artificial systems of lighting and ventilation. 

• Beware of tightly sealed building as they can help trap gases from synthetic materials.  

• Provide for adequate ventilation or fresh air exchange, with good natural ventilation.  

• Designed to give occupants control over their interior environments.  

• Designed to avoid interior condensation.  

• Seal off pollutants found in timber preservatives, particle boards etc to prevent the leaching of pollutants into indoor air;  

• Isolate certain polluting sources, such as having separate rooms for photocopiers.  

• Apply a technique known as a bake-out, to accelerate and so rid most of the harmful off gassing of pollutants as materials usually off gas most of their pollutants while still new.  

• Design for plants and trees as the living processes of plants, cleanse air and absorb toxins.

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• Eyestrain

 

Eyestrain causes headaches, fatigue, stress and leads to the deterioration of eyesight. Common causes of eyestrain are:

• Inadequate natural light.

• Absence of access to external views.

• Glare.

• Poorly positioned and inappropriately lit computer VDU screens.

• Flickering lights such as old types of fluorescent lights (without high frequency ballast’s).

• Single end spectrum lights.

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• Static

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​Common sources, which attract harmful, positively charged ions causing the air to become drained of beneficial, negatively charged ions:

• Synthetic fabrics and carpets, which have not been treated for anti-static.

• Plastics and other synthetics.

• Electrical appliances.

• Steel structures and the concentrated presence of metals.

• To alleviate the problem of the build-up of positive ions better known as static:

• Avoid designing structures using excessive amounts of steel or other metals, as they are draining of beneficial negatively charged ions.

• Design for flowing water, using fountains and flow-forms, as these are high in negative ions and hence excellent neutralizers of excess static charges.

• Plants, especially succulent plants help balance excess static charges.

• Install a negative ionizer

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• Electro Magnetic Fields (EMF’S)

 

EMF’s are invisible lines of force that surround any electric device. More recently epidemiological studies have begun to make links between prolonged exposure to electro magnetic fields and certain types of cancer, primarily leukaemia and brain cancer. While there has been no scientific consensus, other than that better information is needed (Ref: 10), the evidence is mounting that there is a need for design and construction to help reduce people’s risk to prolonged and accumulative exposure to EMF’s. Exposure to EMF does appear to have an accumulative effect and people’s tolerance to them varies. However once a certain threshold has been exceeded, illness will manifest, with symptoms often ascribed to “yuppie flue”. 

While studies on EMF’s are still emerging there are things with design and construction, which should be noted:

• The earth exerts its own magnetic fields, also known as Geomagnetic Fields mainly in the form of DC’s or static fields. This has long been noted, by the ancient practices of dowsing and Feng Shui.

• Power lines, electrical wiring and appliances all produce electric and magnetic fields. With a lamp plugged in but turned off, the voltage produces an electric field. Once the lamp is turned on and current flows, a magnetic field is also produced. For greater safety circuit breakers can be installed for bedrooms.

• Both electric and magnetic fields weaken with increasing distance from the source.

• While electric fields are easily weakened and shielded by conducting objects, magnetic fields are not.

• Buildings located in near proximity to high voltage power transmission lines poses particular danger to children, increasing risks of leukaemia.

• Steel structures generate their own EMF’s due to stresses set up at a molecular level and varying levels of external corrosion. Furthermore steel structures will conduct electric fields induced from any electric circuitry passing near to the structure.

• Electrical transformers emit high EMF’s and need to be positioned with care.

• Prolonged and close exposure to computer VDU (monitors) is ill advised. While low radiation monitors are available, they do not contain the fields and very careful planning of computer workspaces is required so as to reduce exposure, especially around the sides and back of screens where levels of EMF’s are higher.

• It is difficult to escape EMF’s emitted by fluorescent lights.

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