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| Eco Info | Construction |
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Eco-friendly Buildings When we talk about "eco-friendly", most people immediately think of the great outdoors. Fact is eco-friendly also refers to the indoor environment. The indoor environment is created by construction activities and uses a range of different materials. If we continue to use conventional building materials, we continue to subject ourselves to a range of chemical pollutants in the form of volatile organic compounds (VOCs) which are given off by paints, solvents, a huge range of plastic products, composite products such as kitchen worktops and laminated floors, and many more. Even biological pollutants such as dust mite, mould and other spore-generating organisms have been proven to cause all sorts of chest afflictions, headaches and depression, skin conditions and chronic fatigue syndrome. The use of all natural and non-toxic products, good ventilation design and an overall improvement in air quality in the building has been proven to be of major benefit for the occupants. Buildings must be designed and constructed to integrate all aspects of architectural design and energy conservation in a passive construction. When building from scratch, architects ensure that living areas are north facing (in South Africa) or at least within 15 degrees of true north. This allows maximum use of the sun’s energy in the winter months. Architects also position doors and windows to take advantage of prevailing breezes and create a good flow of air through the house. Ceilings and walls must be insulated to retain heat and also to insulate from the heat of the sun. Consider double glazed windows as an aid to heating and cooling. How about painting your roof white? See Ceratech Make provision for planting of deciduous trees in front of windows on the north-facing side of the house. These will lose their leaves in winter and allow sun into the house but will shade the windows in summer. Use paints and adhesives that do not emit volatile organic compounds such as formaldehyde, ketones, solvents and other carcinogenic compounds. Use renewable resources and resources which have a lower carbon footprint. Avoid cement if possible. Cement production is one of the most energy intensive industries. The production of one ton of cement releases about 700 kg of CO2 into the atmosphere. The emissions from the cement industry alone contribute to around 5% of the global total. In Ireland, environmentally friendly cement is manufactured from blast furnace slag, a by-product of steel-making. This is true recycling. Ensure that new houses are plumbed for rainwater harvesting, grey water re-use and also for swimming pool water re-use. Active participation by architects and designers in the eco-friendly rework of the built environment is vitally important. Sustainable Architecture The Worldwatch Institute has estimated that buildings as an entity account for about forty percent of all material resource flow in the world economy and almost forty percent of the energy consumption. Those figures take into account the waste generated and the resources consumed during the useful life of a building rather than just the cost of construction, but never the less, it’s a huge amount of carbon footprint that the construction industry must account for.
Using cement products into the future might not be sustainable; cement manufacture is one of the most resource hungry activities, both from a materials and an energy point of view. Sustainable architecture tries to minimise the impact of buildings on the environment by encouraging moderation in the use of materials and enhancing energy efficiency in buildings. See savutiroofing for some really novel roofing solutions. So what can be done to improve the situation? Below are a few of the types of sustainable design and construction. They have been used in some cases for thousands of years with great success. Construction methods 1. The adobe or mud hut method has been around for thousands of years. It is not suitable in all areas, particularly those areas with high rainfall. The hand made mud bricks must bake in the hot sun for several days to ensure that they will harden off and last for some time. Some regions just don’t get hot enough for long enough to sustain this kind of building. 2. The rammed earth method is more suited to the colder regions where timber is traditionally in short supply. It involves making formwork of some suitable materials into which the clay mixture is rammed. The formwork is then removed. The mixture consists of local sand, gravel and clay in suitable proportions and a stabiliser such as lime or animal blood. Although a number of dry sunny days are required to start off the curing process, the final hardness of the medium is reached after two years or more. 3. Straw bale construction involves stacking straw bales with a skeletal structure of timber or other material, and then plastering the surfaces of the straw bales. This provides a very thick outer skin with superb heat and sound insulation properties. There are two methods of construction, one in which the bales carry the load and the other in which the skeletal structure is the load bearer. 4. There is another class of sustainable construction which is making inroads, although one has to debate whether it will be socially acceptable in the future. Houses are being constructed from found and recycled and re-used materials. There is certainly a case to be made in terms of it focusing on the concepts of reduce, re-use and recycle but elements such as structural integrity, planned design, planned construction, safety and aesthetic appeal must surely be factored into the equation. There are many new building technologies being developed but all are hungry for resources. The challenge remains to find a material and technique which has a very low carbon footprint. |
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