Ecologically Sustainable Development (ESD) is defined as a pattern of resource usage that aims to meet human needs while preserving the environment so that those needs can be met not only in the present, but also for all future generations. ESD brings together concern for the carrying capacity of natural systems with the social challenges facing the larger human population.
ESD is to a certain extent nothing really new; rather it is a recognition that the current pace of resource consumption, particularly in our building architecture design and construction, is not a sustainable undertaking in the longer term. In particular this is having a serious impact on our collective environment, in terms of:
- consumption of none renewable resources;
- loss of natural habit and environment, and
- pollution and general 'wastage'
This environmental impact
is in turn having an impact on ecosystems
that are critical to our survival (such as the carbon cycle
and the water cycle). Global warming
is an example of such a long term net effect of our lack of collective awareness of how to behave a sustainable way.
Ecologically Sustainable Development can be thought of as a three-legged stool, with the legs of the stool being the economy, the environment and society. The stool needs its three legs to function and be stable; without its three legs it will collapse. Similarly, ESD requires a healthy economy, environment and society. If any one of these components is missing, development will not be sustainable.
For instance, a development that fails to consider the social dimension, such as local community concerns about decreased privacy, increased pollution or loss of open space, will suffer from lack of community support. A development that ignores the environmental dimension will result in a degraded resource base. And any successful development must obviously be based on sound economic principles.
ESD, What can you do?
First if you are planning to do a development, you need to seriously consider the environmental impact of such an undertaking and how it relates to ESD. Several issues immediately come in play in a development architecture design and project that control and minimize the degree of resultant environmental impact.
- Reuse of an existing structure;
- Local availability of materials and labour;
- Embedded energy costs in materials;
- Reuse options on building materials;
- The resultant operational 'efficiency' of the finished development.
We shall look at each of these in more detail.
#1 Reusing an existing structure
Often when doing a development the assumption is that any existing buildings and structures on a site will be demolished and removed. This in itself is quite damaging to the environment for the following reasons:
- The act of demolishing and removing the rubbish will use non renewables, such as petrol to power the tools and the vehicles to remove the rubbish.
- The act of demolishing will quite likely create localized pollution in the immediate environment.
Also when you demolish a building you are also destroying all the 'embedded energy' which went into the effort of building it; this is in effect the environmental price already incurred for that building. Think of it as the environmental impact involved in constructing the building anew; you have after all paid for the building you are about to demolish and turn to zero value - so why not see what you can reuse?
Now most builders (and some architects) dislike reusing existing structures, as it means time spent planning, stripping and preparing to make it usable as part of a new plan; hence this can impact on costs and create unexpected problems. The build is basically not so 'formulaic' as starting from a clean slate. Also the builder is often required to provide warranty on their work, so they are in part being dependent upon others work when existing structures are being reused. Also if an architect is involved, there is also the risk of design assumptions about the existing structure being incorrect.
This all being said, it can be often financially attractive to reuse or 'extend' on an existing structure when you can, as long as you remember a few simple rules:
- The existing structure needs to be 'sound'; i.e. no rot, subsidence, termites or other structural damage - as these will all need to be fixed to bring up to code before the new work can start.
- The existing structure should display potential for using as part of a passive solar or energy efficient design - i.e. good building orientation.
- The existing structure should provide good around access (above and under) to allow work to proceed easily.
Also you might the existing structure has features which cannot be easily or cheaply reproduced nowadays; such as fitted furniture, or hand crafted doors or stairs. Sometimes it can be also worth checking under that carpet to see what is actually there (maybe an original teak floor..).
#2 Local availability of materials and labour
Basically the more materials and labour is locally sourced the greater the likelihood that you have reduced your environmental impact. So if you are really serious about doing this you need to:
- Check the local neighborhood magazines for local builders and services;
- Create a little catalog of what building and supply services you have available locally;
- Think about your building in terms of the materials and services that are available locally.
Now this may seem simple at first, but you need to remember the more complicated the components or services that are part of the building process the more environmental impact that results. So you need to be thinking about balancing out the cost of one item against the saving made with another; for instance reusing an existing building could be considered to offset the new building to the same additional area (roughly, assuming the same standard of finish in the old as the new). Or using reclaimed wood for flooring would 'offset' the impact of new flooring elsewhere (assuming the reclaimed wood did not have to travel too far).
#3 Embedded energy costs in materials
The embedded energy of a material or product is basically the energy which went into its manufacture, storage, delivery and installation. Think of it as the 'fuel bill' incurred by using a certain product.
Now the embedded energy costs of a material has a direct bearing on its environmental impact. Simply put the more embedded energy a product contains the more chance there is its has had an impact on the environment. This could either be in the consumption of non renewable resources or the generation of pollutants
or greenhouse gases
#4 Reuse options on building materials
Reusing material can be a viable way of reducing the environmental impact of a building, as long as you are looking at the 'whole cost' picture. For instance, there is no point in reusing existing building structures or components if the total environmental cost is more than that incurred if you used new.. This is why the emphasis on the quality of to intend to reuse; if the structure or component is in good condition then less effort will be required to reuse it.
#5 Resultant operational 'efficiency'
The resultant operational efficiency refers to how much energy and resources are consumed to actually live in the building day to day. Think of it as the environmental 'tax' one has to pay to be in the building. So factors to consider here are:
- Heating and cooling costs
- Costs of supply of water,gas and waste water processing
- General ongoing maintenance costs (painting, cleaning, etc)
Now there are quite a few ways to reduce these costs, see the articles below for details on how to do this.
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