Whether we call it eco-friendly, sustainable, environmentally aware, green – or whatever – the fact remains that all of us are to a lesser or greater degree aware of the environment around us and how we impact it.
For us, this awareness is a constantly developing green philosophy and praxis that also influences how we engage with our shipping container house project. Soon after embarking on the project in 2016 it became clear that there is no such thing as completely eco-friendly / sustainable / green, at most there are degrees of greenness. This is an important point since it compelled us to constantly check and re-check the so-called eco-friendly credentials of building processes, products and materials. Like most other spheres of life, “green” is also subject to marketing and advertising that sometimes take liberties with how they represent something as sustainable or eco-friendly. The result is that a lot of fact-checking and research is required to ascertain the real extent of the greenness of building processes, products and materials. (I don’t know if this is something peculiar to South Africa, or if it is the norm elsewhere in the world too.)
We used the following criteria to determine if materials or products are “in” or “out”, green enough or not:
- Where does it come from?
- What is the environmental impact while using it?
- What happens when it comes to the end of its life?
Where does the material or product come from?
If natural resources have to be mined or extracted in order to manufacture a new product, then it is arguably less green than when the product is manufactured using the by-products of existing resources. For example: if virgin iron ore has to be mined in order to manufacture steel that will be used in light steel frames, it is costing the environment more than when existing steel shipping containers are used to build with. A lot of energy (which equals a large environmental impact) is used in mining and manufacturing. A building method can be considered greener when it takes waste materials out of the environment, for example building with decommissioned shipping containers or recycled car tyres (such as in building Earthships). The embodied energy of a product, i.e. the energy that was used in the manufacturing of the product – for example the energy that was originally used in the manufacturing of the shipping containers or car tyres – is a crucial aspect in deciding how green it is.
(Part of the question of where raw materials or manufactured products come from touches on the issue of local vs imported products – which I will deal with in a separate post.)
What is the environmental impact while using the product or material?
The environmental impact of a product or material does not end once you have bought it. What are the environmental costs of using a product or material? For example: our shipping containers have already been manufactured using Corten steel (designed to last for a very long time), and during the conversion process from steel boxes to a house it was again treated for rust and painted with super-duper specialist paint. It will not require a lot of maintenance, i.e. the potential future environmental impact is relatively low. In comparison, if you build with timber it would most likely be virgin timber (since it would be very difficult to find recycled timber in large enough pieces to use for the construction of a house) which would mean that you have to check that it is FSC certified, i.e. from a sustainably managed plantation or forest. The timber will have to be treated (which will probably not be a very environmentally friendly product – as is the case in all likelihood with the paint used for the containers), and regular maintenance may be required. If the maintenance (and ideally the original treatment) can be done using an eco-friendly product it will be OK, but if not then the ongoing long-term impact on the environment will be negative.
What happens with the material or product when it comes to the end of its life?
The greenest products or materials are definitely those that can be re-used, re-purposed or recycled. If its final resting place is the rubbish dump then you have definitely chosen the least environmentally friendly material or product. In the case of our shipping containers, the entire structure can be recycled or re-purposed into something else. (For great examples of repurposing “rubbish” have a look at the stunning work of Jan Vingerhoets of ReDeux.)
Some lessons learned about the greenness of materials and products:
- Don’t believe everything the salesperson or label tells you, double-check the facts.
- If it’s imported it can’t be very green – importing leaves an enormous carbon footprint.
- The impact of maintenance should not be underestimated.
- The end point of materials or products should be as important as their start.
- It is more difficult to recycle composite products (such as composite “wooden” planks made from recycled plastic and timber).
- The intrinsic value of material is in the eye of the beholder. Don’t be discouraged from using something because other people don’t like it.
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