One of the sustainability aspects that became crystal clear while building our shipping container home is how difficult it can be to retain the link between green building practice and the use of local products and materials.
The term “local” describes manufacturing and distribution that are based near the consumer rather than nationally or internationally. It assumes that manufacturing takes place close to the consumer’s home (i.e. within X kilometres of a consumer) and that goods are therefore transported over shorter distances.
The challenge is that there is no universally agreed-upon definition for the geographic component of “local”, i.e. how far away from you is nearby or “local”?
The shipping containers that we used for our container home have been converted in Maitland (Cape Town), the plot where they will stand is in Baardskeerdersbos, and our primary home is in Stellenbosch.
“Local” has been variously defined as referring to:
- A distance within a place’s own boundaries e.g. within the boundaries of Baardskeerdersbos itself.
- A distance within a city boundary e.g. within the municipal boundary of Cape Town or Stellenbosch.
- A distance within a neighbouring town boundary e.g. within the boundary of Gansbaai – the nearest “bigger” town to Baardskeerdersbos.
- A distance within a regional boundary e.g. within the Overberg region that incorporates Baardskeerdersbos.
- A distance within a provincial boundary e.g. within the Western Cape.
- Or a distance within the country boundaries e.g. within South Africa.
So what does it mean if we use our shipping container project as an example?
We sourced the hot water boiler in Bredasdorp, 55km from Baardskeerdersbos. A distance which can surely be viewed as “local”. However, since we thought it necessary to test the boiler at home (in Stellenbosch) before installing it in Baardskeerdersbos, we had to make a round trip of 340km. As it turns out, the 340km trip was unnecessary. What does this mean from a green building point of view? Our needless trip produced roughly 0.06 tonnes (or 60kg) of CO₂ emissions. (We can, fortunately, offset this by planting about 6 trees.)
The principle of local sourcing also applies to the contractors that you use and, hence, to the principle of building local economies. We used a local builder, who lives in Baardskeerdersbos, to do some of the preparatory work instead of “importing” someone from one of the neighbouring towns, or from Stellenbosch or Cape Town. This means that the materials that he bought contributed to building the local economies of Gansbaai, Stanford and Hermanus. It also provided work for a couple of local labourers.
What’s wrong with local roof sheeting?
Sometimes the question of buying “local” can extend as far as provincial boundaries or even country boundaries. The roof sheeting that we decided on is a good case in point. Most of the salespeople wanted to convince us to use Zincalume steel, an Australian product manufactured by BlueScope Steel consisting of a mix of 55% Aluminium, 43.5% Zinc and 1.5% Silicon. Despite the fact that there is an equivalent South African product called ZincAL, manufactured in Cato Ridge in KwaZulu-Natal by SAFINTRA, with exactly the same mix of 55% Aluminium, 43.5% Zinc and 1.5% Silicon. The two products are in all technical respects the same, yet the imported Australian product was punted as the better option. Why? It seems that, as South Africans, we think that imported products are necessarily of better quality than those manufactured locally. By insisting on ZincAL we not only supported our domestic economy, but also significantly reduced the huge carbon footprint of importing steel (the carbon footprint of the South Africa ZincAL steel is already big enough…)
And the problem with local plastic “wood” is…?
Another such example is the growing number of imported composite decking materials. They are manufactured from recycled wood fibre and polyethylene plastic, or reclaimed timber and recycled plastic, or bamboo fibres and recycled plastic, or even cellulose fibre cement. While these products could be described as sustainable in their countries of manufacture, such as China, the USA and Malaysia, can we still call them “green” when imported? The materials that are recycled during the manufacturing process are not South African landfill. They are the “rubbish” of other nations. And the jobs that are created and the economies that grow are not ours (at least not directly). Ironically, South Africa has a growing sector using recycled plastic and other materials to manufacture composite plastic “wood” such as Enviro Timbers in KwaZulu-Natal, Primwood Products in Hermanus, EcoWood in Modimolle (Nylstroom) and NewLife Plastics in Muizenberg.
These are the “local” options that we should support, rather than the imported products which drag their huge carbon footprint halfway across the globe to reach our shores!
Using locally produced building materials and products shortens transport distances, thereby reducing air pollution and the carbon footprint of air, road or rail freight. Often, local materials are better suited to climatic conditions and they support the growth of local economies. Of course it is not always possible to use locally manufactured materials and products. But a good rule of thumb is: if it must be sourced from further away, use it selectively and in as small a volume as possible.
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