An interview with Dr. Wolfgang Seeliger (Leichtbau BW) and Beate Wittkopp (TransferWorks BW, the Steinbeis Transfer Center) about the future potential of lightweight design

Lightweight design offers plenty of potential – as underscored by a 2019 study issued by Leichtbau BW, the biggest lightweighting network in the world. The study looks at the role played by “Lightweight in the Urban System.” TRANSFER met up with Dr. Wolfgang Seeliger, managing director of Leichtbau BW, and Beate Wittkopp, Steinbeis Entrepreneur and member of the Leichtbau BW advisory council, for an interview.

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Dear Ms Wittkopp, dear Dr. Seeliger. Could you start by giving us a quick overview of the main thrusts of the study?

Wolfgang Seeliger: Lightweight design offers 50 percent material weight savings, you use 40 percent less energy in the mobility sector like the delivery of goods, and there are reductions of up to 60 percent in terms of the effects caused by urban heat islands – our study identified that these positive benefits are already possible today if you use lightweight design in an urban setting. A great deal of the current discussion on sustainability is about closed-loop recycling. We are talking about enormous flows of resources here. For example, the construction industry creates roughly 50 percent of all waste and uses around 40 percent of all resources. If you just think about the potential savings, you can see why lightweight design offers a solution to this problem.

We now have an indicator model that gauges the sustainability of an urban quarter as early as during the process of the request for proposal. The model does not look at individual buildings or sections of buildings, but instead it assesses the sustainability impact of integrating several functions in one building, as well as planning and construction processes spanning across different disciplines. It is a complement to existing indicator models, such as the system used by the German Sustainable Building Council (DGNB) – so you can assess entire urban areas by looking at the big picture.

Beate Wittkopp: The study could not have come at a better time. Not only is it an enrichment to preparations for IBA27 [editors note: “IBA” is an acronym for “Internationale Bauausstellung”; in English “International Building Exhibition”; it is  organized by the regional council of the city of Stuttgart], it also makes specific recommendations regarding project implementation. One factor which makes this study so special is the aforementioned indicator model. We finally have a robust basis for changing the way cities are planned in the future, introducing more elements of resource efficient lightweight construction. The idea now is to develop this model into a measurement system so it can be applied in the real world.

What role do you think lightweight design will play as a planning feature of future cities?

Wittkopp: Problems tend to stand out more in cities, which is why there is more pressure to do things differently there. But cities are already in place. So we need to work out if there is any room to maneuver, which is where lightweight design can make such a big difference. The timing is ideal because the IBA27 is a special opportunity to develop concepts by working on an interdisciplinary level, and for forming new alliances. Projects can be implemented that set an example, and we can try things out in certain areas and experiment.

Seeliger: Lightweight design allows us to give cities back to the people. Cities become more pleasant to live in. Until now, open areas like the streets, parking garages, and parking lots have belonged to cars. This is where lightweight design comes in, acting like a catalyst. The study shows that first and foremost, we need to think across sectors. What do I mean by this? Fields such as modern mobility, urban infrastructure, and architecture should not be seen as separate entities. What we need to do is to merge different sectors of the construction industry and adopt an integrative approach when it comes to developing concepts, planning, and finally building cities. This is the only way to maximize the potential savings.

So what needs to be done for that to happen?

Wittkopp: We have to take into account the fact that cities also compete against each other as economic zones and places to live.

Seeliger: Definitely. Although there is a lot of interplay between these things. One of the reasons Berlin has been so successful as a city of entrepreneurs is that it holds appeal for young and hip people. Berlin was and still is “in” and it has leveraged that fact as an economic asset. If you look at Berlin now, though, in terms of urban development it is anything but appealing. But now we have the ingredients that allow us to make cities more pleasant to live in again. Let me give you an example. The ILO is a prototype for an innovative lightweighting vehicle. It only weighs a third in comparison to a conventional vehicle and – which is much more important – it only occupies a quarter of the area. Imagine what the city of the future would look like if you reverse the equation and 75 percent of the space taken up by traffic were freed up? We could give this space back to the people. There would also be integrated logistics solutions based on lightweight vehicles, using last-mile distribution systems integrated directly into buildings. This would also affect how goods are delivered within cities, in ways that are more compatible with people, and more efficient, and that also make it possible to free up space. This reverses the famous weight spiral and pushes it downward, and the savings would trigger other (secondary) impacts which in turn would reduce the consumption of resources in a kind of positive feedback loop.

And how do we get to this city of the future?

Wittkopp: In my opinion, dealing with this question shows how much potential exists to be innovative by approaching things on an interdisciplinary level and using overlapping models. It sheds a completely different light on modern construction. But this transformation requires widespread participation and a high level of personal identification of the population with changes. I believe that the best way to deal with most of the problems that arise when you move to a future-ready habitat – one that really is sustainable – is to work on solutions across different sectors of industry.

Seeliger: What the study really highlights are the opportunities and potentials offered by a holistic approach. What I mean by this is that we have to stop looking at disciplines like road construction, building construction, and transportation within urban areas as separate entities; we have to think of them as an integrated part of the overall urban process. One example described by the study, which really illustrates the topic of functional integration well, are multifunctional hubs. These are types of buildings that unite several logistical functions, and because they are used in different ways they do not take up much space. Materials travel shorter distances and they are shipped via several carriers, so the first thing these hubs do is to reduce city traffic. But they also offer different types of buildings and different living options for new target groups. For example, micro-apartments not only help to shorten carriage drives, they also limit the amount of space used in urban areas. With multifunctional hubs, energy supplies can also be made multifunctional and self-supporting. One way to extend this and create further synergies would be to introduce flexible building formats, like co-working spaces, fablabs, or urban farming on rooftops.

Wittkopp: The only way to exploit the tremendous potential to make savings in urban design and really achieve a circular economy in the way it is meant – in terms of resource management and material recycling – will be to develop connected usage scenarios and introduce the highest possible material standards.

Current developments in industry, such as digitalization, smart production, and connected systems, are resulting in convergence as established borders evaporate and areas that were previously separate start to merge. What impact will this have on lightweight design within the context of urban systems?

Wittkopp: A huge impact! For example, we can transfer expertise from the automotive industry in the region to urban development, and achieve genuine innovation on the roads.

Seeliger: These developments are a huge opportunity for the region, because these trends are dealing with our core competences. And when I say core competences, I do not mean traditional ones like carmaking or mechanical engineering – I am talking about the ability of these fields to create highly complex products, based on logistics and manufacturing processes that depend on one another and are closely intertwined. The excellence cluster at the University of Stuttgart is actually already dealing with the task to transfer this core know-how into urban design. The cluster is called Integrative Computational Design and Construction, and its aim is to use machines to automate major sections of the construction process and make it more productive, and also form a direct link between planning, pre-production, and the construction process itself – which is not possible without deep-seated digitalization, affecting all parts of the process. The way I see it, this project paints a picture of the potential way forward for the region in maintaining its competitiveness, especially if the traditional sectors of commerce are no longer as viable as they are right now.

Lightweight design is a significant factor when we are talking about sustainabililty. What challenges can this sector of industry expect to be confronted by when it comes to urban design, and what should be done about them?

Wittkopp: We need to improve living standards in urban areas without negatively affecting the surrounding areas. And that will only work if we succeed in exploiting the potential offered by buildings – for example the infrastructure – but also make more effective use of green spaces in the city and close material circles.

Seeliger: The challenge we face in the cities is that we will have to offer more housing and living space to more and more people. Around two billion of the people on earth are currently in their childhood. Professor Werner Sobek has estimated that we would have to rebuild the entire world of 1930 to create enough housing and infrastructure for the generation of people that is currently growing up. If we want to do that with “German standards”, we would need roughly one thousand billion tons of concrete and brickwork. This number is not just inconceivable, we would not be able to produce the resources to do this. Lightweight construction is a sustainable technology by itself because you only use the amount of material you actually need. We have to seize the huge potential offered by lightweight design to save resources – we have no other choice.


Leichtbau BW has just released a free App (iOS/Android) with an augmented reality function that you might like to try. To try the feature out on this article, install the app and tap on the Augmented Reality button directly from the main menu. Focus your smartphone camera on the cover of the study (opposite) and prepare for a surprise…

You can also download the app by going to www.leichtbau-bw.de/ios or www.leichtbau-bw.de/android. The app is only available in German.


Beate Wittkopp (author)
Steinbeis Entrepreneur
Steinbeis Transfer Center TransferWorks BW (Schönaich)

Dr. Wolfgang Seeliger (author)
Managing director
Leichtbau BW GmbH (Stuttgart)