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 project. 

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 sustainable building material. 

What you may not know is that aluminium is not just aluminium. The same goes for recycled content. The incorrect terms may lead to confusion by overstating the environmental benefits - with the potential of undermining the credibility of the aluminium industry. 

So when manufacturers talk about their systems being produced with recycled aluminium content using terms like pre-consumer and post-consumer scrap, it helps to know the difference. It's a pretty significant one. 

​Pre-consumer vs post-consumer scrap - what's the difference?

Firstly, recycled content covers both the pre-consumer 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 yet 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% 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 gone through its full life cycles and is ready for disposal, recycling or reuse. A 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, separations, shredding, decoating. The metal also needs to be x-rayed to determine alloying elements, and the 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, TECHNAL parent company Norsk Hydro has created Hydro CIRCAL - a range of aluminium products made with recycled, post-consumer aluminium scrap, like facades and windows that have been dismounted from buildings and fully recycled. 

Currently Hydro offers Hydro CIRCAL® 75R, with at least 75% recycled aluminium from post-consumer scrap - with one of the smallest CO2 footprints worldwide : at 2.3kg of CO2 emissions per kilo of aluminium. This is 86% or 7 times less than the global average for primary extraction. 

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 scrap are included. 

To meet the growing demand for more sustainable products on all building projects, all TECHNAL UK windows, doors, sliding systems and facades are now produced with Hydro CIRCAL® 75R - the 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, DOORS AND SLIDING SYSTEMS FOR SUSTAINABILITY CREDIBILITY

• Check Traceability

A good starting point is checking the aluminium product 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. 

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