Why aluminium dominates architecture

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Aluminium has become a decisive material in architecture. Not least because of its outstanding properties in terms of sustainability. One driver of this development is GSB International. An interview with GSB Managing Director Werner Mader and Marketing Manager Philipp Mader.

ALUMINIUM: The contribution of aluminium to sustainability is well known. But why is the material so exciting for architecture and the development of more sustainable cities in particular?

Werner Mader: All the positive properties of aluminium come into play, especially in windows and facades. High-quality, quality-assured coatings applied by means of powder or liquid paint give aluminium an impressive appearance on the outside, contribute to decades of value retention and form an important cornerstone for sustainable coexistence. The face of the world's most famous skylines is formed by aluminium – that's no coincidence.

ALUMINIUM: So the material would have to be the big issue in this area?

Werner Mader: When it comes to awareness among architects or permits from building authorities: definitely! On the construction site itself, of course, the focus is on other issues, but here we definitely see ourselves as mediators between the worlds: For example, we can advise on what is possible in terms of color or design.

Philipp Mader: Our member companies often have their own architectural consultants. For example, not every color tone can be used in areas with high UV radiation. Here, the companies have to find the optimum solution together with the architects.

ALUMINIUM: To what extent has the sustainability of aluminium become part of the image of good architecture?

Werner Mader: In the past, aluminium was primarily known for being very energy-intensive in production. However, thanks to the material's good recyclability and outstanding durability, this image has changed significantly. In addition, architects and planners appreciate the design possibilities. Unlike steel, for example, you are not limited to a few profile shapes, but can produce a profile for every requirement. In times of batch size 1, this is an enormous advantage. And the return of this material to the cycle generally works really well, the scrap is in great demand.

By the way, you can see that aluminium is extremely valuable by what happens when you leave a dismantled facade on the construction site: It's gone the next day! I think word of the material's high value has long since got around. The downside is that every gram of aluminium used in a facade is taken out of circulation for 30 or even 50 years.

ALUMINIUM: The GSB produces numerous quality guidelines. Can you explain their thrust and significance for the industry?

Philipp Mader: These guidelines were and are created by the members for the members. And in a democratic sense: by two elected committees with representatives from the entire membership and the entire supply chain. In principle, the guidelines are developed beyond the standard. 

Werner Mader: The quality guidelines are primarily aimed at coatings for outdoor use in architecture. Quality assurance is particularly important at this point, because the coating accounts for only a fraction of the cost of a facade. However, if quality defects occur here, in the worst case scenario an entire facade has to be dismantled and recoated. In addition, the duration of the use of coated aluminium in architecture is particularly long.

Coated aluminium facades must retain the impressive appearance of the first day even after many years. This makes close-meshed and well thought-out quality assurance like ours necessary. Independent accredited testing institutes regularly verify that our member companies adhere to our quality guidelines.

This confirmation of the quality level by neutral third parties has led to the fact that coatings according to the GSB quality guidelines can be found in many tenders of the industry in addition to the tenders in architecture. Our guidelines therefore radiate far beyond GSB itself.

ALUMINIUM: I assume that your field is also subject to permanent technological change?

Werner Mader: Absolutely! On the one hand, of course, in the area of inspections; here we have really reached a new level of flexibility. In times of lockdown, for example, we were able to perform remote audits using helmet cameras – a solution for emergencies, but of course a big step. Then there is the significantly expanded range of online training courses. But of course we are also experiencing permanent developments in the R&D area.

Philipp Mader: A lot is really happening in the area of coating in particular. For example, in the area of the development of pretreatment materials with regard to process stability: chrome-free pretreatment processes were less stable at the beginning, but that has changed significantly. A hotly debated topic at the moment is gas-fired ovens for baking powder coatings. Also in view of the development of gas prices, low-temperature coatings are increasingly being discussed in the industry.

Werner Mader: Another point: The standards allow some leeway in some cases, which means that tests can sometimes produce different results. We therefore test our testing institutes among themselves by means of anonymized round robin tests to see whether they arrive at the same results.

Philipp Mader: Recently, we tested pretreatment by laser together with a partner company. Here we achieved surprisingly high qualities in the coating. The process is not yet economically viable in the field of coatings for architecture, but it was a way of thinking outside the box. Classic basic research, if you will.