One of the problems in relation to sustainable development and more specifically, sustainable building, is how to define these terms: what is sustainable building (SB)? In many parts of the world, and even between experts, the concept is interpreted differently. In general, it may be said that balanced resource-use on a global scale is one of the aspects involved (e.g. energy, materials, water, land). These physical elements are the most tangible: availability is limited, negative environmental impacts are well-known and there are strategies to reduce resource use (although these have so far been only very partially implemented). Next come the human scale aspects: healthy living conditions, comfort, and social and cultural adjustment to people’s perceptions of what life is, with its needs and desires. All this has to be established within the national political context, with the economy as a regulating system, research supporting solutions and sometimes religion as structuring framework. These three scales are sometimes summarised as ‘ecology, sociology and economy’, or as ‘people, planet, profit’. This suggests the same level of importance for all three. However, the physically available resources (energy, materials, clean water, clean air, land, etc.) set the limit on the material framework within which people can create their welfare, while the economic system (with profit as a part of it) has to facilitate this, and is not a goal in itself.
Trias Ecologica
The Trias Ecologica has proven to be a useful strategy in developing sustainable and environmental concepts. This principle states that the first step is to reduce the need for or use of anything. The next step is to use renewable sources to meet the need. And if 1 and 2 are not sufficient to cover the activity, Step 3 can be applied: supply the remaining needs as efficiently as possible. Applied to energy this leads to a major reduction in demand (through insulation, efficient ventilation, daylight optimisation, etc.), the introduction of renewable energy sources (e.g. solar collectors, passive solar gains by design, solar electricity, etc.) and highly efficient use of fossil fuels to meet the remaining need. These steps need to be applied in that order.
The same approach can be used for materials, water consumption, and even for maintenance or installations. (See the relevant chapters).
Closed cycle approach
By natural progression, the Trias Ecologica approach leads to a closed cycle approach in which all needs are taken care of in steps 1 and 2, and step 3 can be eliminated. At that point, non-renewable resources are no longer needed, and there will be a balanced situation for the activity. It will not be possible to reach this optimum situation with an ‘adding measures’ approach; innovative and creative concepts are needed. Of course, this cannot be implemented in a day or a year, at least not on a wide scale. Nevertheless, the concept should be clear, and any decision to establish part of the concept should be made in such a way it does not compromise the total concept at a later stage.
The above text fragments are excerpts from the book: A conceptual approach to Sustainable housing. ( published january 2008)
See for more details also the closed Cycle resource management section.
