Green in a circular economy
Aluminium is one of few materials that keeps its properties after recycling. With an increase use of sustainable products, developers need to be well informed about the current terminology being used to describe products, according to Allan Barr, sales director at Technal UK, who discusses why it is important to understand the subtle wording manufacturers use and how to specify a sustainable green facade.
Aluminium can be remelted and used again and again in new products, making it a sustainable building material. However, how manufacturers label their products can be incredibly important.
When facade manufacturers talk about their systems being produced with recycled aluminium content, using terms like pre-consumer scrap and post-consumer scrap, it is important to understand the difference between the two. 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.
Pre-consumer or process scrap is production waste from manufacturing processes, such as an extrusion, where the metal has not been made into a consumer product. It may have been anodised or painted but not yet used. It is collected from production, returned to recycling plants, and then melted again for something new. This is a sustainable process because when aluminium is recycled, about 95% of the energy used in the production of primary aluminium is saved.
On the other hand, 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, through recycling or reuse. For example, an aluminium window frame in a building can be considered post-consumer scrap when the building is demolished and the aluminium is obtained and remelted, then used in a new product. While this yields a lower carbon footprint and is appealing from a sustainability perspective, the post-consumer scrap has a much more complex manufacturing and production process. It will need to be thoroughly inspected to determine alloying elements, as different types of alloys cannot be melted together if manufacturers want to produce a top-quality metal.
There are several more elements to consider when specifying aluminium curtain walling, windows and doors for sustainability credentials.
Check traceability. 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.
Certification proof. 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.
Currently, Technal parent company Norsk Hydro offers its Hydro Circal range of aluminium products made with recycled, post-consumer aluminium scrap, such as facades and windows that have been dismounted from buildings and fully recycled.
Its Hydro Circal 75R range is available with at least 75% aluminium from post-consumer scrap – one of the smallest CO2 footprints worldwide – at 2.3kg of CO2 emissions per kilo of aluminium. This is 4.5 times less than the global average for primary extraction.
Engaging with an aluminium systems supplier early in the design process and working closely with them throughout is key when it comes to achieving a sustainable building solution. With more than 60 years’ experience and a global network of resources, Technal can help clients meet their sustainability requirements.
To avoid misleading customers, any manufacturer or producer marketing products with a recycled content of 90% or above should disclose what fractions of post and pre-consumer scraps are included. This can help ensure the credibility of the aluminium industry and make sure customers are selecting the right product for their project.