Tip #3: Choose materials with low-embodied energy.
Well, I have to admit that before I could evaluate the difficulty involved in this tip, I had to do a little research to learn what the heck they meant by "low-embodied energy". After a lot of wandering around on the web, I learned that what it means, basically, is this:
- When you're choosing building materials, you need to consider the total amount of energy required to manufacture a product. This could include the gathering of the materials (i.e. mining), the work needed to compile the product (i.e. firing bricks), and the energy costs of transporting the building materials from the place of manufacture to the building site.
We chose our building materials with several criteria in mind, but low-embodied energy wasn't one of them, I have to admit, simply because I wasn't aware that it should be.
There are many ways in which our pathway is still a good choice for a green garden. It is set in sand with gaps between the pavers, allowing rain water to filter through instead of running off. It's light-colored and reflects heat and sunshine rather than absorbing it. The concrete pavers are simple and unglazed, reducing some of the chemicals that might have been used to make them.
However, you just can't define concrete pavers as using "low-embodied energy" to manufacture. Concrete ranks high on the scale, as the cement and stone must be mined, then manufactured into bricks, and then shipped - and these pavers are certainly not lightweight.
So now I know, and that's half the battle. Going forward, I can choose materials that do use low-embodied energy, especially those made from sustainably-harvested wood materials. Here's what I could have done differently:
- Chosen different materials for the path, such as locally-collected gravel, sustainably-harvested woodchips, or crushed shells (certainly easy to come by locally!).
- Looked for a different source for the pavers, rather than buying them new. If someone else had pavers they wanted to get rid of, I could have purchased them used rather than buying new pavers that needed to be manufactured and shipped.
- Created a different type of path, perhaps one using flagstone stepping stones, so fewer materials would be needed.