DESIGNING SUSTAINABLE FACADES IN A CIRCULAR ECONOMY: HOW TO CHOOSE THE GREENER ALUMINIUM
How do you know whether the recycled architectural aluminium systems you’re specifying are made from aluminium that’s actually been used before or is simply ‘clean’ waste from the production process? More to the point, why should you care? With developers and architects increasingly looking to design for a circular economy, here we clear up some of the subtle yet significant terminology and explain how to get the right green facade product for your next projec
As you’ll know, aluminium is one of few materials that keeps its properties after recycling. It can be remelted and used again and again in new products, making it an environmentally friendly metal and a sustainable building material. What you may not know is that aluminium is not just aluminium. The same goes for recycled content. The incorrect use of terms may lead to confusion by overstating the environmental benefits – with the potential of undermining the credibility of the aluminium industry.
So when façade manufacturers talk about their systems being produced with recycled aluminium content using terms like pre consumer scrap and post consumer scrap, it helps to know the difference. It’s a pretty significant one.
Pre-consumer vs post consumer aluminium scrap – what’s the difference?
Firstly, recycled content covers both the pre-consumer scrap and post-consumer scrap in the product.
- Recycled pre-consumer or process scrap – Manufacturing waste
One source is aluminium process scrap. This is production waste from manufacturing processes, such as extrusion, where the metal has not been made into a consumer product. It may have been anodised or painted but it hasn’t actually been used. It is collected from production, returned to recycling plants and then melted again for something new.
This is positive, considering that when we recycle aluminium, we save about 95 percent of the energy used in the production of primary aluminium.
- Recycled post-consumer scrap – End-of-life or reclaimed aluminium
Post-consumer aluminium scrap is metal that has been used in a product that has gone through its full life cycle and is ready for disposal, recycling or reuse. An aluminium window frame in a building, for instance, can be considered post-consumer scrap when the building is demolished and the aluminium is obtained and sent on to be remelted, then applied in a new product.
What the difference means - The higher the post-consumer recycled content the lower the carbon footprint.
It is more difficult to produce top-quality metal that has a high content of post-consumer scrap. However, it yields a lower carbon footprint so is therefore more appealing from a sustainable building perspective. Going back to the aluminium window frame. An aluminium frame has probably been anodized and painted. It may also contain thermal break – the insulation within the frame. Conversely, process scrap is basically ‘clean’ metal. Recycling the aluminium from a window frame is a complex process with many steps. Inspection, separation, shredding, decoating. The metal also needs to be x-rayed to determine alloying elements, and segregated. Why? Because different types of alloys should not be melted together if you want to have similar high-quality alloy back from the recycling loop.
Preventing this aluminium waste going to landfill, SAPA parent company Hydro has created Hydro CIRCAL - a range of aluminium products made with recycled, post-consumer aluminium scrap, like façades and windows that have been dismounted from buildings and fully recycled.
Currently Hydro offers Hydro CIRCAL® 75R, with at least 75% aluminium from post-consumer scrap - one of the smallest CO2 footprints worldwide: at 2.3 kg of CO2 emissions per kilo of aluminium. This is 86% or 7 times less than the global average for primary extraction. The company is working to launch new products with even higher content of recycled aluminium in the future.
To avoid misleading customers, a producer marketing high average recycled content of above 90% in their products should disclose what fractions of post and pre-consumer scraps are included.
To meet the growing demand for more sustainable products on building projects, all SAPA windows, doors and facades are now produced with Hydro CIRCAL® 75R – a high quality recycled aluminium or Hydro REDUXA - a certified low-carbon aluminium.This means as architects and specifiers your designs will already be meeting standards including green building certifications such as LEED, BREEAM and DGNB. What else to consider when specifying aluminium curtain walling, windows and doors for sustainability credibility
A good starting point is checking that the aluminium production process is fully traceable, and that an independent third party, such as DNV-GL, certifies the product.
Systems may also have passed other certifications such as the ift Rosenheim, an EPD (Environmental Product Declaration) or the international Cradle to Cradle™ certification.
Meets green building standards
In addition, there are aluminium system products on the UK market that meet standard green building certifications such as LEED, BREEAM and DGNB.
How can you ensure higher recycled aluminium content in your next building?
If your next build has a requirement for a sustainable aluminium system package, specifying this text in the tender document will provide clear direction for your supply chain:
The system makes use of recycled material in the following area:
• Aluminium with material usage of at least 75 % end-of-life (EoL), e.g. EN AW-6060 T66.
For aluminium with EoL recovery, material that has already been installed in and removed from a building is recycled once more. The minimum 75 percent proportion of this post-consumer material (≥ 75% EoL material) must be verified by means of independent certification.
Case study: Økern Portal
One project in Scandinavia with Hydro CIRCAL is Økern Portal. The project will be BREEAM-NOR Excellent-certified, which is one of the highest certifications for construction. Sustainability has been in focus in all parts of the construction process. Hydro CIRCAL has helped both the developer and the architect to achieve the sustainability goals. To create a sustainable building, there must be a good and close collaboration with the supplier of the construction system early in the process.
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Sapa Building System offers architects, specifiers, metal fabricators, investors and home-owners worldwide an extensive range of innovative, reliable and
aesthetically pleasing aluminium systems for curtain walling, façades, doors, windows and building-integrated photovoltaics. Sapa Building System is one of the
largest suppliers of aluminium building systems in Europe and is part of the global aluminium company Hydro.