Aluminium has been chosen as a suitable building material for decades as specifiers see the material as one of the most recyclable choices which is readily and plentifully available. This can also be said for many metals used in construction such as copper and steel. Plastics have also come a long way over the last few decades and now offer a longer and useful life. New formulations do allow for varying amounts of recyclability which is one of the most recent innovations.
There seems to be a perceptible concern among specifiers about the use of metals in construction which is based on metals ‘high embodiment’ of energy. There is no denying that this is the case and that when sourcing metals, smelting and shipping are expensive both in monetary and energy resources. One has to consider, however, the complete recyclability of metals and in particular aluminium's unique credentials in this area. Over the last 50 years the energy needed to produce aluminium from bauxite has reduced dramatically due to the introduction of new technology and over half of this energy is now provided by renewable hydro electric power.
Virtually no other commercially available material can offer the strength to weight ratio of aluminium. This ensures buildings can be built lighter and consequently use less supporting structure which reduces building costs. But what about the ‘Embodied Energy’ of metals and in particular aluminium?
Aluminium has been produced commercially since the 1880’s and it is estimated by the International Aluminium Institute that at least 75% of this material is still in use today. Aluminium is almost 100% recyclable using only 5% of the original energy required to produce it from bauxite making aluminium a strong contender for the most sustainable material known to man.
The BRE’s Green Guide is an extensively researched publication offering specifiers a much needed guide when choosing materials based on a ‘cradle to grave’ approach. Materials such as timber score well and so it should being a natural and warm material for our building needs when sourced from sustainable forests.
When we come to a material such as aluminium we must take a ‘cradle to cradle’ approach. How many materials do we know that have an indefinite life span, to date of over 120 years, and where 75% of all material produced is still in a useful working life? The International Aluminium Institute initiated a programme called ‘Aluminium For Future Generations’ which closely monitors this bank of recyclable aluminium used in all walks of life from packaging to aircraft and of course construction.
Aluminium in use today, carefully looked after and efficiently recycled, can last over a 1000 years and undergo many transformation’s without loss of material properties.
It has been acknowledged that the metals sector has legitimate concerns about the assumptions made by BRE regarding recycling. The writers of the Green Guide never intended the publication to discriminate against materials, yet we have controversial adverts and materials beginning to compete against each other rather than manufacturers looking forward and developing their materials for future sustainable use.
At CAB we are confident that the debate will stabilise when the Green Guide is fully understood by specifiers and is used as part of the decision making process when choosing materials. CAB is not suggesting that aluminium is a superior material to all others, but aluminium does offer some unique characteristics which give specifiers freedom in design. To rule aluminium out of a project, because of procurement authorities current misunderstanding of how to apply the Green Guide, restricts specifiers design freedom.
CAB is available to offer guidance to specifiers on the use of sustainable aluminium in construction. CAB is always keen to emphasise the value of membership of the association, whether a company works with aluminium or is a provider to the supply chain. Further information about CAB can be found on their website at www.c-a-b.org.uk . or by contacting Julie Harley at the CAB offices on 01453 828851