09 March 2011

LiveBlog: Sustainable in a Material World

Meg Calkins, Ball State

Editor of the forthcoming Sustainable Sites Handbook to be published in October 2011 by John Wiley and Sons.  Author of Materials for Sustainable Sites (described by L+U as a "must read")was published in October 2008.

For an aluminum rail in Indianapolis she breaks down all of the environmental impacts of that rail.

Millennium Ecosystem Assessment (2005) concluded that ecosystem resources are critical to support life on earth.  And that society has caused irreversible damages.

More than 90% of the materials that goes into the average US product is waste before it reaches the users.  80% is molecular waste that goes into the air or water, etc.  But if you consider closed materials and resource loops, "true waste does not exist".  Good green design recognizes that and makes use of it as a guiding principle.

The first case study is the High Line. The heavy reliance on cement is a good starting point.  We can often reduce it.  Sometimes we can use substitutes like fly ash, slag, and natural pozzolans like calcined shale.  Another concern are the woods used.  If they were rainforest materials they are not renewed as well as others.  Certified wood would be better - this can include accounting for the chain of custody.  Plastic lumber is a much harder sell, but if you use it make sure you avoid PVCs.  For materials like stainless steel and aluminum, we should be considering the level of embodied energy.

If we are going to make progress on this front, we need to make a minor or less radical shift on projects like this.
But we need a major shift in materials that we need to seek out as well.

The 2nd case study is at the Queens Botanical Garden.  One innovation was rammed earth structures, which can be used anywhere.  It is high-labor, low-cost and low-impact.  Don't confuse it with Compressed Earth block (CEB).  The radical shift in materials is needed to "close the loop".

Alternate materials can include gabions with concrete or stone rubble from on-site. Stabilized soil pavement requires binders, whether they are plant-based (agave, pine resin, seed oils), and polymer binders can help us stop using so much paving.  Natural barriers can replace fencing. 

Ecobalancing - life-cycle flow of resources that balances inputs and outputs to support vital whole systems.

Finally an example was provided using an interdisciplinary student project from outside Muncie.  One included a 5ac demonstration site for a family, because 5ac is the footprint of a single family.  The designs also included selective harvesting of a forest on site, permaculture areas, strawbale construction (currently not legal in the US) and AlgaeWheel technology.  Even an incremental shift in construction methods will require proving the reliability of these techniques and showing people the benefits.

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