Building a sustainable design specification pt. 1
- Building Design Expert
- 5 years ago
Specifying for a Sustainable Future pt.1
It is perhaps unfortunate, and just a little saddening that sustainable building en masse is not just around the corner. As an industry we know how to do it, and indeed it has been done, or come close to. But such inherently sustainable buildings still exist as one-offs. As landmark architecture, and the stuff that populates architectural design competition listings.
Searching for a globally accepted definition that the construction industry can work towards is truly uphill. The aims are clear and generally accepted, so perhaps we don’t need a definition? But without defining a goal, how can we possibly know when we have scored? So in scouring the web’s offerings on ‘sustainable design’ and ‘sustainable architecture’ you might concur on this:
“Sustainable Design uses technology and materials that are replaceable through natural process at a rate equal to, or greater than their consumption”.
Having put together a form of words that amply states the case, we must surely ask is it perhaps just too ‘text book’? Whilst it maybe our wildest dream, a lack of mass market application takes it out of the realm of practical execution? However, with a bit of reshaping, we might more readily aspire to:
“To remain practical ‘Sustainable Design’ may often be required to make a ‘Best Fit’ with available and affordable technology, resources and materials”
Indeed, to remain meaningful, one should actually follow the other to underline the fact that in order to work towards mass market appeal something is going to have to give, usually in the form of a compromise to make that ‘Best Fit’..
Embodied energy (EE) can be an invisible erosion of all things that have such outwardly sustainable credentials. It doesn’t have to be, but consider the import of a stainable grown timber from say – Scandinavia. The importer finds an equivalent product that is importantly cheaper, but it is shipped from New Zealand. Does the importer have a moral dilemma? To the ‘Green Lobby’ he certainly does, but this is Money. It could improve profitability, secure employment and so the company’s long term outlook. So what is our importer to do? Which way will he jump? I think we know the answer. The price? A product indistinguishable to the end user, but one with a far higher, and thankfully invisible embodied energy.
Unfortunately embodied energy is unquantifiable. There can never be a global code that can measure two products that are anything but not the same. That is why EE largely figures as a background rating. Consider if only one product fits the specification bill, but it is made ten thousand miles away using large quantities of energy in its production – so high EE then. But high compared to what?. The upside is that it is so energy efficient that after 30 yrs it will have paid back all its embodied energy such that it becomes a carbon neutral installation. The question here is that ‘Is 30 yrs too long?’ When other key components achieve neutral status after only 10 yrs. Factor in the human designer, and a thousand other variables on a complex building design, and then cast your vote.
High Energy Products with High Sustainability – Lead, Copper, Zinc and Aluminium. On the one hand you could say that we are really pushing the ‘Best Fit’ boundaries. On the other hand, are we really thinking outside of our normal box.
Lead – depending who you read, at our current rate of consumption world wide reserves of commercially mineable ore are estimated to expire in around 40 yrs. The bad news is there is a global annual consumption of between 8 and 9 million tonnes that fuels that estimate. The good news is that just over half that figure is accounted for by recycling.
Lead is 100% recyclable. Install it on a roof and it will give you circa 100 yrs. of loyal service. Consider using a modern alternative roof covering, and the chances are you will have replaced it three times during the same period. If we think about embodied energy how far up the ladder does that put lead?
Take a look at Ecobuild’s profile video below, and catch up with pt. 2 of this blog published next.
You can visit the LSA stand when you go to Ecobuild
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