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Simple LCA to Measure the Impact of Where Stuff Comes From

How do you measure the impact of where stuff comes from, and why is this important?

Life Cycle Analysis

Measuring the overall impact of stuff is the objective of life cycle analysis, or LCA. The type of impacts considered in LCA include:

  • Where the raw materials come from
  • How far they have to travel
  • The impact of the manufacturing process
  • The distribution process
  • End of life impacts
  • The energy inputs required along the way

Why does LCA Matter?

LCA could be considered a measure of sustainability. The less the overall impact, the more sustainable a particular product or material is. If we want to create sustainable homes (and I think we all should), then we need to consider the impact of all the stuff we use to build. LCA provides a way of doing this using a common measure.

So how do you measure the impact of where stuff comes from?

Carbon as a Measure of Impact

The impacts at each stage of mining, milling, harvesting, refining, fabricating, transporting, using and deconstructing; can be converted the common metric of carbon. In general, the more carbon dioxide (or equivalent) released during all the life stages of the material or product, the higher the impact.

In some cases there will be lots of other impacts like:

  • Water usage
  • Impact on natural habitat and biodiversity
  • Other chemicals released to the atmosphere or water streams
  • Depletion of a non-renewable resource

Part of the role of LCA is to convert all these impacts into a common language and carbon happens to be a useful one.

LCA is Complicated

With so many factors involved at all the stages of producing a product, delivering it site, using it, and allowing for it after it’s design life, it’s easy to see how things can get complicated. Add to this composite products like framed windows, hot water systems and appliances that are made up of lots of materials, and it gets even more complicated.

Finally, there’s even more complication arising from the site-specific nature of transport costs.

Therefore LCA is something that has to be done specifically for each building design and in each location.

Making LCA Simple


eTool provides a simple tool to do something complicated – Life Cycle Analysis of building products

The objective of eTool is to provide simple LCA for homeowners and designers to measure the impact of where stuff comes from.

eTool is the brainchild of Rich Haynes and Alex Bruce. I caught up with Alex and spoke to him about why he created eTool and how he sees the future of building.

Got a project in mind? Why not register and try out eTool for free?

Is Solar Power Sustainable?

In our interview, Alex explained that 15% of Australian households now have solar power generation. But is solar sustainable?

When someone asked Alex if it took more energy to make solar panels than what the panels were actually capable of generating, he didn’t know the answer. The search for that answer is partly what led, eventually, to eTool.

Book Recommendation

Alex’s book recommendation is Making Your Home Sustainable: A Guide to Retrofitting, by Derek Wrigley.

Comments on this entry are closed.

  • Elrond Burrell

    Another great podcast Matthew, I thoroughly enjoyed listening. The only problem is it’s such an interesting subject and Alex had so many interesting things to offer that the podcast can only just touch the surface of it all!! One of the most useful discussions around LCA I’ve heard for a long time though, too often it is seen as a box-ticking, carbon counting exercise rather than a whole life design approach.

    Interesting intro discussion about the merits of different environmental / sustainability accreditation schemes and what their different but complimentary purposes are. I think another distinction can be made that something like Passivhaus is a design process (& PHPP is a design tool) which is really useful for the designers involved, whereas BREEAM, LEED, HomeStar, GreenStar etc are accreditation schemes that evaluate the project, none of them are design tools as such although of course they can influence the design if used intelligently.

  • Kara Rosemeier

    … if used intelligently is an important caveat. Talk to anyone using tick-box schemes, and they will tell you stories about horse trading. It’s as if those schemes rather discourage intelligent usage with their prescriptive options, and elusive weighing factors. It would be great to see that the decisions to award points were based on research that is properly referenced. Post-occupancy evaluated, accredited buildings often fall short of expectations. I refer for example to Joe Lstiburek’s rant in which he called the US LEED programme misLEEDing, based on evaluations of ill-performing, highly awarded buildings. A friend did similar evaluations in Germany, with similar unsatisfactory results. I am all for holistically looking at the impact of buildings on people and the natural environment. But: there is no short-cut to a holistic analysis, and attempting to do this on-the-cheap has a very high margin of error, which puts any results into question, in my view. On the other hand: no one is prepared to pay for doing this properly. A project that I was involved with at the margins attempted to come up with an assessment for materials alone (they got a heap of grant money for this), and it took a bunch of scientists half a year to analyse the impacts on the environment of most the materials used alone. Surprising insights were gained, like: the material used for the cable jackets really made a difference in the overall environmental performance etc. How do you measure whether a 6 star building is actually kinder to people and the environment than a 5 star building? Why does energy, comfort and indoor air quality amount to 48% of the score and not 51% (or 44)? Would it not be better to rate buildings based on measured performance (indoor air contaminants, water and energy consumption, comfort) rather than based on promises? We could actually learn from the latter …

  • Thanks for confirming that Carbon assessment study is Voodoo Science and not very accurate for real mathematical calculations. I say go carbon heavy on quality materials on 500 year plus structures. everyone is getting so wrapped up with this Carbon print idea, they are losing focus on today’s BIG picture “Climate Change”.

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