31.10.2024

Music island with awning

Building design

Architects Shigeru Ban and Jean de Gastines have built a new music culture center on a Parisian river island. “La Seine Musicale” rises out of the waves like a stone ship. The bow is crowned by a spectacular glass concert hall sphere.

The long, narrow Seine island of Île Seguin has undergone a dramatic transformation. Formerly home to a large car factory, the place is now all about music. Japanese architect Shigeru Ban has built a music center here, which is intended to attract artists, fine spirits and music lovers to the island. The most striking feature: A flattened, glass sphere that towers over the flat concrete substructure like a billowing sail.

It is this glass sphere that initially puzzles the observer. What might it contain? Its function only becomes clear during a tour of the complex.

At the heart of the project are two large and very different concert halls, the smaller of which occupies the interior of the sphere. It seats 1,150 listeners and is particularly optimized for the performance of classical music. The other hall, the “Grande Seine”, is located opposite in the eastern part of the complex and directly at the main entrance. With a fan-shaped layout and steeply rising stands, it is tailored to pop and rock concerts; it can hold up to 6,000 people and also has a particularly spacious stage.

A house within a house

The main access axis, the “Grande Rue”, leads from the building entrance to the smaller hall in the dome. Approaching the “Auditorium” – as the venue is called – in this way, it becomes clear that this is an independent house within a house.

The introverted hall volume is surrounded by bright walkways and enclosed by a transparent building shell with a hexagonal timber structure. The self-supporting timber construction, a free-form structure on an oval ground plan, is made of glulam elements and was realized using parameterization and CNC production. Its size – 27 meters high, 70 meters in diameter in the longitudinal axis and 45 meters in the transverse axis – is just as remarkable as its construction: the 3,300 individual parts are largely put together like a 3D jigsaw puzzle using overlapping panels to create the overall shape. The hexagonal pattern is created by the double-curved wooden beams that intersect at the intersections.

Floating glass egg versus technoid protective shield

A charming, wide walkway unfolds between the concrete shell of the hall and the wood and glass shell, an extraordinary spatial creation with a sweeping view over the Seine – until the mighty steel structure of the solar sail enters the picture.

The triangular, curved shell segment partially shades the façade, reduces cooling requirements and generates electricity. However, the aesthetic quality of this element with its technoid structural “inner life” was the subject of controversial debate when the Seine Musicale was completed in 2017.

Proof of sustainability

The approach is certainly to be welcomed: the sail is part of the building’s environmental sustainability and energy concept. The client had already specified his desire for a large-scale PV system in the competition. Instead of simply placing it on the roof, Shigeru Ban designed the triangular mobile “sail”, which follows the course of the sun and thus makes power generation more efficient.

At the same time, the shadows that fall on the glass façade and in the walkways around the concert hall change with the course of the day. A multifaceted interplay of light and shadow unfolds here with the reflections in the river and the reflections of the shimmering green mosaic on the hall wall.

All photos: Didier Boy de la Tour.

22.10.2024

Architecture

“We are increasingly trying to incorporate light as well.”

Building design

Ulrike Schartner and Alexander Hagner from gaupenraub+/- Credit: Markus Kubicek — Ulrike Schartner and Alexander Hagner from gaupenraub+/-
Credit: Markus Kubicek

gaupenraub+/- is an established name in architecture and is particularly well known in the media for its social projects for the Vinzenz communities. Ulrike Schartner and Alexander Hagner spoke to Baumeister about human-centered planning and architecture as a process that is not affected by apparent restrictions.

Baumeister: Let’s start by explaining what your name is all about.

Ulrike Schartner: The name gaupenraub comes from the dormer windows that we want to rob and is actually thanks to a building owner. In the late 90s, our first building projects straight after graduating were typically Viennese loft conversions. In our first project, we wanted to remove all the dormer windows and replace them with a spacious solution. She said she couldn’t be robbed of her dormer windows.

But in its broader meaning, it stands for complexity. A dormer window is something added on top. Right from the start, we have been trying to develop more complex solutions instead of creating more surface area, more thermal bridges. We are celebrating our twenty-fifth anniversary this year, so we can say that it works well.

Alexander Hagner: At gaupenraub, it was actually clear that we were repelling people who wanted bay windows or Doric columns on their property to a certain extent. It was a signal. We simply couldn’t do anything with our own names and we didn’t want those who work with us to have to identify with us.

B: Who are these others that you work with?

US: It varies, but of course we work a lot with our clients. That sounds a bit strange, but we develop the spatial programs and other things together with those who are already on site, especially in the social projects.

AH: Not enough with clients! More and more, but overall less than we had imagined, including with other players in terms of space production. We would have liked more of that. That’s only just starting to happen. I have the feeling that architects planning things on their own is a thing of the past. It was already important to us back then to work together with others on interdisciplinary projects. This openness should suggest the +/-.

In the beginning, there were structural engineers, then building services engineers and building physicists, and today we are convinced that we also need more and more sociologists if we want to build. After all, if everyone is talking about our environment, architecture is also a part of it. As a professor at the Carinthia University of Applied Sciences, I work on the effects of the Anthropocene. That should have been over long ago and we should be more aware of the fact that we live in coexistence.

So far, this has primarily referred to marginalized groups. But at the university in particular, we are increasingly realizing that coexistence must actually mean: everything that is alive, especially animals, plants, simply everything that is still given too little consideration in planning. Because architecture simply does too little for them. But architecture must also move away from this human-centeredness. We are seeing this more and more and are also working with our office and at the university to broaden the focus as much as possible.

B: How did you get involved in social construction?

AH: We realized relatively early on, about 20 years ago, that we had skills that others could use very urgently. I read in the newspaper about Pastor Pucher, who wanted to set up a village in Vienna that had already existed in Graz for nine years and was working well: the VinziDorf for homeless people. I asked Ulrike if we would like to support it on a voluntary basis, at least for the time being. I then simply got in touch with him and asked if he could use us as an architectural firm. He said he needed everyone and since then we’ve been involved and more than ever, fortunately – and unfortunately fortunately, because it’s a huge field and it’s getting bigger and bigger.

Unfortunately, the work is still precarious when it comes to social projects, i.e. projects for people outside the majority society. There is an attitude that we should invest less in such things and that they should be happy that they are getting something. But that’s not exactly how it works and that’s why so many social projects work so badly, because even in architectural production, the focus is not on the people you’re doing something for, but on the lack, such as the lack of money or land.

With architecture, if it’s halfway OK, we’re talking about ten, fifteen, thirty years of existence, and if it’s good, over 100, 200 years. If we make mistakes, then we cement the stigma, this situation of disadvantage, so to speak, for a long time. We saw it differently right from the start in the sense of: When it comes to people with difficult biographies, people on the run, people with disabilities or restrictions or who are homeless, we have to do more because we first have to compensate for an existing deficit. I believe that we have a special reputation because of this approach and our ideas, which we have been able to implement again and again over the course of 25 years.

We have radically broken with the image that social projects smell funny, look funny, feel poor and are somehow not sexy. Such projects in particular need points of contact for support so that people who are disadvantaged can get their feet back on the ground in society. We can use architecture to build bridges between areas where there is a lot and those where there is nothing. The more beautiful we design the architecture, the better the projects are set up on the hardware side, the easier it is to get support from a wide range of areas; from the construction industry, but also from private individuals.

We can use the beauty of the design to build slides so that more goes where it is urgently needed. I think you can also tell that our work is a huge pleasure for us. But at the same time, we always maneuver ourselves into a very precarious position to a certain extent, because although it is rewarded incredibly well, it is only in the form of idealistic appreciation and not in terms of fees. And it’s difficult to survive with that.

US: The EU has the noble goal of virtually ending homelessness by 2030. However, it is heading in the opposite direction. Due to the climate crisis, wars and the like, there will be more and more homeless people who have to leave their homes for completely different reasons and who will very likely also come to Europe. That’s why architecture needs to work more in this field. The issue will also reach completely different groups of people, no longer just those who have perhaps lost their jobs or have always been social outcasts, as in the past.

It also affects young people who can no longer find housing because everything has become too expensive. It is no longer just about a small group, but about all social classes. We can’t eliminate this with the resources we have. But in reality, you can’t say that nothing is being done for social housing in Austria or Vienna. A lot is being done.

We are in favor of a broader range of offers. Of course, there is council housing or Housing First, but the offers are often not so broadly diversified and therefore not suitable for consumers, i.e. people looking for housing, to actually be able to take up these offers. Very specific projects are needed. For example, this VinziDorf, where only alcoholic men who can no longer be integrated into society are taken in. They are given a quiet place to grow old and die.

Normally people say that if you build for disadvantaged groups, then it’s only a temporary solution, because they will pick themselves up, come back into society and then everything will be okay. But we have met so many people for whom this is not just a transitional stage, but where you have to give them the opportunity to stay there. We haven’t actually designed any of our projects for a short period of time. People are allowed to stay as long as they can and want to, which also has to do with a certain autonomy and dignity. Nowhere is there an end date after which we say you have to help yourself.

B: Keyword support: Should architects be thought of differentlyas sovereigns, namelynot in this “free market, servicesituation”, but perhaps position them completely differently in society?

US: A difficult question. We mainly build for private associations or NGOs, but a lot of support comes from patrons. There are philanthropists who put their money from family foundations into social projects. Each individual should contribute as much as he or she can. But of course, the state also has to do its part. It’s like a kind of network. I don’t believe that the market economy alone can solve this. It can’t be like in America, where you have to rely on other people who donate a lot of money. But we have to admit that we wouldn’t have been able to realize at least three of our projects if it hadn’t been for this kind of private donation. I see it very differently.

AH: It’s also always about housing. You mentioned post-growth before our conversation. It would make our work so much easier if the issue of housing were removed from the (turbo) capitalist system, in the sense of a basic right to housing. Unfortunately, you can’t sue for this anywhere. Actually, all countries, especially in our area, enforce the right to property more strongly than the right to housing. We can see from cities like Paris or London how things are developing and where we are drifting.

I’m thinking of Victor Papanek and his book Design for the Real World from 1971, which calls for 10% of what you have to be made available to the community. That doesn’t just mean money, but also ideas or skills. We like this idea. We are part of a community and cannot survive without it. Our tax system is also based on this idea. For us, architecture work is a shortcut between this credit and debit. But I agree with Ulrike: the state is just as challenged here, and a rethink is needed.

We need more diverse offers. In Vienna and similar cities, for example, we have renovated away all substandard apartments and are super happy about it. But in reality, we have simply reduced the spectrum enormously. This arrival city element, where you come as a student, as a young person, freshly moved away from your parents and looking for an apartment, without money, that almost no longer exists. Nowadays, you can’t find anything to live in except “same old” architecture, only smaller and further out on the outskirts of the city.

Because I used to be prepared to share a toilet in the corridor with a Mrs. Paul, I was able to live in the central district. We are proud of the improvement in housing standards, but in reality it makes it impossible for people arriving here to decide: Would I rather take the toilet in the corridor with Mrs. Paul or move somewhere on the outskirts of the city into a super small apartment?

We want to experiment with ways of living that take account of this increasing individuality in our society. We are all such poor individuals, but as far as the housing market is concerned, there are only similar, small floor plans. For example, there used to be large apartments in central locations, but without central heating. You could decide whether to buy coal at the weekend and heat the oven, or whether to go to a coffee house, take the money and treat yourself to a proper meal.

These choice scenarios no longer exist. Experiments would help against this, but they’re extremely unpopular. “Pilot project” still works, you get the feeling that someone is at the wheel. The state or the city are not the right partners because they operate with taxpayers’ money, and experiments can fail, just like pilot projects. You can’t justify that to the taxpayer. That’s why we worked our way through the first few years with public clients and actually saw them as more of a hindrance to our projects.

It is not the case that there are so many people on the streets in Vienna because there are not enough offers. There are simply too few offers tailored to the people. We are convinced that we need a broad spectrum; Housing First is suitable for some people, while others need some kind of group housing project, but these cannot look like building groups because they deal with other structural issues.

The greatest danger with special offers is that they also look special. And that’s where we try to take the needs into account on the one hand and at the same time not stigmatize them by their appearance. At VinziRast-mittendrin*, nobody would think that this is a social project where homeless people and refugees play a major role. It’s a completely normal part of the city.

With our tools, we can set an example in terms of architecture against marginalization, but in our experience this is only possible with partners who can free themselves from guidelines and norms. Then you can say, let’s try something and develop projects for the future. Because as Ulrike has already said: We are becoming more and more human. Walls and fences won’t help. We have to prepare for this, and we believe we can do this in architecture too. This also requires a commitment from those in power. We could certainly fail, but we have to do something.

Martina Malyar was the head of the ninth district in Vienna, and when we told her about the project to let students and homeless people live and work together, she immediately understood. She was the first politician in Vienna to say that she found it very interesting and was behind us. Up to that point, when we had already been active for 10 years, we had never experienced that before. The opposite was the case: attempts were made to politically prevent the VinziDorf. VinziRast-mittendrin has now been in existence for eleven years, the VinziDorf for six years in Vienna. Once things are built and become a reality, it is possible to take the wind out of the sails of critics. But unfortunately, this is not yet possible with politics. But of course there are exceptions like Marburg, where we are currently being taught better.

B: What is happening in Marburg right now?

US: The municipality of Marburg in Germany has heard about VinziDorf and wants to replicate it. This is our first public commission to realize such a village. It is a village because it is about people who were excluded from social interaction. In the village, everyone has their own little house and the community in front of their noses, which they can accept, but don’t necessarily have to. Most emergency shelters have dormitories where you have to go in in the evening and leave again in the morning. But not everyone can cope with that. For those who have lived on the streets for a really long time, this is not an alternative. For them, there is this village with a communal house where they can eat together and where there are showers. The community is offered, but not necessarily required. There is no compulsion.

If there has been any criticism of our projects, it is most likely that these rooms are tiny. The idea behind it was better to have a permanent, small place to live than nothing at all. Because with these projects, it’s often “all or nothing”: we have to do everything and then it doesn’t work because this is too big or that is too expensive. Instead, it’s better to find out what the basic needs of the people you’re building for are.

We want to take all clients seriously, regardless of their social status. Often the greatest need is to have a door that you can lock without having to worry about being robbed or even threatened. In other words, this very small, personal, intimate space that nobody is allowed to enter, that you really have to yourself and that provides security. And when this security has really become tangible after a few weeks, then people come out and start socializing again. In the village in Vienna, for example, which has been around since 2018, there are already real communities and people look out for each other. This social inability to get along has turned into togetherness. That’s great to see. That’s exactly what the people of Marburg want and should have.

AH: Hillary Silver is an American sociologist who said that it’s not the roof over our heads, but the social structures that support us. We believe in that. And now we’re thinking of marginalized groups, refugees, homeless people, who are always force-fed group projects, apparently due to this need. These people, with their difficult biographies of fleeing, of surviving on the streets, have to be forcibly compatible within these group projects, so to speak. It’squite clear that this doesn’t work, isn’t it?

For example, a project is currently being planned in Munich for 830 homeless people in a building with 3 wings – and is called Overnight Shelter. The costs for this are in the double-digit million range. I don’t want to be security, users or support staff there. I wouldn’t want to be there at all, it’s a dead end. When you go there, you know: Now you’re really on the sand.

We actually always try to incorporate light into the projects, i.e. the perspective, the light on the horizon. On the one hand, we define our wellbeing in mainstream society through our social relationships, which recharge our batteries. But we humans also define ourselves through the meaningfulness of our lives. We are interested in much more than just living in projects, which is why they are becoming increasingly hybrid. For us, the hybrid is one of the solvents, for example in terms of occupancy. The projects are not just for homeless people, but also for students. They are curious, keen to experiment and want to broaden their horizons. And as a young person, you often simply can’t afford your own apartment.

Students are ideal contact points. But of course they also need the right room program. That’s our big criticism of competitions, where you’re already given that. We prefer to develop it together with the users and clients. That’s a huge lever as to whether the project turns out well or not. For the time I’m in a place, it shouldn’t matter where I come from, where I’m going afterwards, but only whether there are structural settings that make it possible to have a good time together. And occupation plays a major role here, i.e. doing things together.

AH: Finally, informal living should also be mentioned. We can learn so much and benefit so much from informal structures that don’t come from architectural planning or are even prescribed by government circles, but that arise of their own accord. Things that arise without regulation should be looked at much more and welcomed in the municipalities.

US: We have found that the right group size for people living together is around 30 people, which is about the size of an old school class. That’s how we were socialized. That’s how we find our way around. We can remember each other’s names. But the group also tolerates it if you only like five of them. There is a certain kind of choice, you can build relationships. A company is also much more likely to tolerate projects if they are spread out in small groups across the whole city. The neighborhood can also get involved and we see a lot of synergies, like in Mayerling, for example. That was an abandoned hotel with a laundry. There is a nursing home in the neighboring village and we thought: we can do the laundry for them as well. There are so many possibilities when you think more locally. We always want to give something back to the neighborhood with our projects. We want there to be a connection between the outside and the inside, without isolation.

AH: Nobody in the neighborhood likes “homeless projects”. You can plan the most beautiful architecture, but you can’t get it approved if the neighbors send you death threats. So we have developed strategies over time. A society thrives on symbiosis. If a structure is too infested with parasites, it dies. Architecture should also be thought of symbiotically, without a fixed focus on a result, but rather on development, on the processual. In other words, not exactly as we have learned and as it is still taught at many universities, that the beautiful, well-designed object (keyword icons or landmarks) is then finished at some point, a ribbon is cut and you are happy that it looks almost as beautiful as on the renderings. That is no longer the idea of architecture.

When designing with the processual in mind, we realized that this is how we discover so much potential. That’s why our new credo is “form follows resource”. Resource in the sense of gray energy, of course, but also of infrastructure, people, neighbors, animals, plants, in other words, everything that is there. In this respect, we architects actually have to develop into specialists and train the perception of the next generations: Where are we and what is here?

AH: We just have so many products and things. We are super rich kids and should see how far we can get with what we already have. For projects, for example, you develop formats such as a flea market, where you inform people, but also get their opinions and suddenly get ideas on how to expand the spatial program.

Residents are local experts, and when they realize that their thoughts are being incorporated into the project, then we have already dealt with the issue of identification. Then the organism is suddenly expanded and not some kind of implant that might be rejected. We also try to get young people involved in the project, schoolchildren, apprentices, students, in other words the younger generations in particular, especially in very difficult projects like the VinziDorf, which is about tangible homelessness.

AH: Once we have used architectural planning to give young people a starting point for a project like this and they take part, they will think differently about homelessness, for example, for the rest of their lives. They realize that most of the stigma is prejudice. Of course, it’s also incredibly difficult to work like this and financially incredibly unprofitable. But the projects are then developed, discussed, built and realized together, which means that we are no longer designers of dead matter, but have now become designers of living processes. That’s super gratifying. Nevertheless, we also have to look again at where the next other, i.e. conventional, projects will come from, from which we can then also make a living.

B: Do you need a bit more autonomy? What would make architectural work easier for you and therefore for society?

US: More freedom to work in an environment where you are simply allowed to do certain things. In Germany, there is also this building type E, E for simple building, and we in Austria are also working on it, even if there are a lot of question marks surrounding this topic. For example, this is something we need to take a closer look at.

US: In the beginning, we were always forced to build with the existing stock because we couldn’t afford the new. And what we couldn’t afford in the past for social reasons is now also an issue for mainstream society. Only now, due to a global emergency, the focus is on how we need to deal better with what is there; that instead of building regulations, there should be conversion regulations and so on. Something that is already being considered, but where I am a little afraid that it will all take far too long. We are incredibly slow and we are simply running out of time.

We’re at the end of our careers rather than the beginning, and we’ll still be able to finish our work. But I’m really worried about the children and young people who are just starting out. How is this going to continue if we don’t step up a gear now? Everyone says “well, in 15 years we should have solved this”. But I realize that we’ve been talking about it for 5 or 10 years and nothing has really been solved yet. And if it continues at this rate, then I’m really very worried. That’s why I have to bring a little hope back into play. Alex is the optimist with us, just like you, Ramona. You’re young, you’re interested and, fortunately, I have the feeling that there are more and more like-minded people.

AH: At the university of applied sciences in Carinthia, I have the feeling that young people are interested in all the topics that could be subsumed under the keyword “building turnaround”. They are slowly realizing that if we carry on like this and continue to use the subjunctive – we should, we ought to – that this is simply not enough. We have to switch to the imperative and exert pressure, especially from below, i.e. from the population of the Global North and our region. We have to have our necks full, now. I find it totally arrogant that we are still carrying on like this, namely towards all those who can’t, indeed: fortunately can’t, because it wouldn’t work out if everyone lived like we do.

Our thinking goes like this: “Oh yes, the room height is 10 centimetres too low, isn’t it? The insulation isn’t OK or the barrier-free access isn’t right, is it? Well, let’s move it and redo it.” We believe that architects are so creative. We have to redirect this creativity to questions like: How far can we get with the things we have? How do we meet the new challenges that we as architects are supposed to solve? We have to use this creativity to identify potential in order to look at something that is disruptive or annoying until it perhaps even becomes something that creates an identity for the entire project. Ulrike always says to tell stories.

AH: When you walk through Berlin and look at the new buildings there, you immediately shudder. They are virtually nanocoated. They don’t address the users or city dwellers. They are so artificial that we are almost back to artificial intelligence. I miss the human connection with both. On the other hand, I see circular building as a huge opportunity to develop architecture where patina plays a role, where traces play a role, where you simply realize that it’s not out of the retort or copy-paste times 3000. The hopeful thing is that young people are also interested in this.

And if we now move from the subjunctive to the imperative, that will help us enormously. As architects, being part of a group that thinks about the environment, as specialists in the built environment, opens up so much more, it’s so much more exciting! I can only think as far as I can think in this brainpan. As soon as I invite someone else to think with me, it gets further, and if I then get even more involved with a given situation, it gets even further. So we are both Wolf Prix’s students. In order to create serendipity, a happy coincidence, they put a plan or a drawing on the photocopier and moved it during the copying process. Then they saw what came out of it and some of it was simply translated into architecture. This inviting of coincidences or of what I am not myself to leave my own brain allows you to discover so many things.

AH: We architects believe that we are more important than ever. But there are even more people involved in our work who urgently need to have an influence on architectural production and development. That’s why we need even more people who have the right training to ensure that all the structural components, which are becoming more and more numerous, can be built into something that will last for a hundred or 500 years. That’s a huge responsibility. You need people who have an overview in terms of training. That again speaks in favor of this generalist, which was said to be dead for a while.

None of us believes that he or she is better than a carpenter or a locksmith. But we still need someone to keep an eye on the big picture and hopefully this work will be reserved for architects. Hopefully we won’t be rationalized away because, well, some building developer will do it, he’ll manage. The solo genius, the architect, so to speak, is practically dead. We see ourselves more as mediators.

http://gaupenraub.net

*see also Baumeister 1/2014, page 60 to 67

The questions were asked by Ramona Kraxner.

06.02.2026

Resilience and sustainability

How cities are draining – techniques between decentralization and system logic

Building design

A rainy street in a city as a symbol of urban drainage and heavy rain management between decentralization and system logic. — Wet road surfaces illustrate how modern urban drainage manages water, prevents damage and ensures urban quality of life.

Rain, heavy rain, dry spells – cities face enormous challenges in the 21st century when it comes to drainage. How can an urban landscape intelligently manage water, prevent damage and at the same time create an environment worth living in? The answer lies in a fascinating field of tension between decentralized solutions, systemic infrastructure and urban innovation. Welcome to the world of modern urban drainage, where technology, ecology and urban design merge to form a new discipline.

The importance of urban drainage systems for climate resilience and quality of life in cities
Historical development and paradigm shift: from centralized sewer systems to decentralized, multifunctional solutions
Central techniques of urban drainage: urban water management, sponge city principle, blue-green infrastructure
System logic versus decentralization: conflicting goals, synergies and innovative approaches
Practical examples from Germany, Austria and Switzerland – from rainwater management to retention roofs
Technical, legal and social challenges in the transformation of urban drainage concepts
Interaction between urban planning, landscape architecture and water management
Outlook: Digital tools, monitoring and the role of data for sustainable urban drainage

Urban drainage in transition: historical foundations and new challenges

Urban drainage is not a new topic, but dates back to ancient times. Even the Romans built complex sewer systems to drain rainwater and wastewater from settlements. For centuries, sewers were seen as the ideal solution: Water had to be removed from settlements as quickly and efficiently as possible to ensure hygiene and prevent flooding. However, this logic is reaching its limits in the 21st century. Heavy rainfall events, increasing land sealing and climate change are putting traditional systems under pressure. The consequences are visible: flooded streets, overflowing cellars and stressed sewage treatment plants are now part of everyday urban life.

The cause lies less in the technology than in the paradigm. Centralized systems that rely on rapid drainage are rigid and not very adaptable. In a dynamic, dense urban structure with ever new requirements – such as quality of stay, greening and climate adaptation – new answers are needed. This is precisely where the paradigm shift begins: away from one-dimensional drainage and towards multifunctional, decentralized solutions that see water as a resource. The term “sponge city” is more than just an urban buzzword. It stands for a philosophy that retains water, allows it to evaporate, stores it and makes it usable.

But the transformation is complex. It requires a new interplay between urban water management, urban planning and landscape architecture. It is not just about pipes and canals, but about integrating retention areas, infiltration troughs, green roofs and open watercourses into the urban texture. At the same time, the requirements for control, monitoring and maintenance are increasing. Technical progress, social rethinking and political decisions go hand in hand.

The challenges are immense: How can centralized infrastructures be combined with decentralized elements? How are responsibilities regulated when private and public areas intertwine? And how can we create acceptance for visible water in a society that has relied on displacement for decades? Every answer to these questions will shape the city of the future.

One thing is certain: Drainage is no longer a purely technical field. It is a melting pot in which ecology, urban design, social issues and technology are interwoven. Only those who understand and shape this complexity can make cities truly sustainable.

Technologies between system logic and decentralization: the new repertoire of urban drainage

Modern urban drainage makes use of an impressive toolbox that goes far beyond the classic sewer network. The focus is on the balance between systemic logic – i.e. the integrated network of sewers, retention basins and wastewater treatment plants – and decentralized elements that absorb, store or evaporate water locally. The key: only the interaction of both approaches makes cities resilient to the challenges of climate change.

The core of the system logic remains the sewer network. It ensures the orderly drainage of wastewater and rainwater, protects public health and forms the backbone of urban water management. However, the load limits have been reached. Heavy rainfall events lead to hydraulic overloads, combined sewer overflows pollute rivers, and expansion is reaching its financial and spatial limits. This is where decentralized technologies come in: They relieve the overall system by retaining the water where it occurs.

The most important decentralized elements include swales, infiltration areas, retention roofs and cisterns. They temporarily store rainwater, allow it to evaporate or seep away and thus create buffer spaces in the urban water cycle. Green roofs have a dual function: they improve the microclimate, provide a habitat for biodiversity and at the same time delay runoff into the sewage system. Open water areas such as rainwater gardens or streams in the city are also playing an increasingly important role – both for water management and for the quality of life.

A prime example is the sponge city principle. It aims to keep as much rainwater as possible in the urban area and make it usable. Areas are unsealed, watercourses reactivated, more trees planted and green corridors networked. At the same time, new forms of retention are being created: multifunctional squares that serve as temporary reservoirs during heavy rainfall, or parks that become seasonal retention basins. Technology is increasingly taking a back seat – what is needed is integration into design, use and infrastructure.

Nevertheless, control remains a challenging task. Modern sensor technology, digital monitoring systems and smart control systems are becoming increasingly important. They make it possible to measure outflows, monitor storage levels and control specific measures as required. In this way, the city itself becomes a learning system that reacts flexibly to weather events. The challenge: technical excellence must be combined with planning and design intelligence.

Practical examples from Germany, Austria and Switzerland: between innovation and reality shock

What does this look like in practice? A look at current projects in Germany, Austria and Switzerland shows: The transformation of urban drainage has long been underway – but it is not without frictional losses. While some cities are implementing ambitious sponge city concepts, others are still struggling with bureaucratic hurdles or a lack of acceptance.

Berlin, for example, is setting standards with its “Climate-friendly rainwater management” program. Here, new districts are planned from the outset in such a way that rainwater does not seep into the sewage system, but is instead stored on the property. Green roofs, trough-trench systems and open water areas are standard. As a result, the city remains dry even during heavy rainfall – and gains in quality of life at the same time.

Vienna, on the other hand, is pursuing an integrative approach with its “blue-green infrastructure concept”. Here, drainage, open space design and climate adaptation are considered as a unit. The Danube Island acts as a huge retention area in the event of flooding, while infiltration basins and artificial streams in inner-city parks provide cooling. The result: a city that does not fear water, but uses it.

Zurich also relies on innovation: in the new Greencity district, all buildings have been equipped with retention roofs and cisterns. Rainwater is collected, used for irrigation or slowly released into the ground. Digital control systems ensure that the systems work optimally – and provide valuable data for urban planning. But not everything runs smoothly: legal uncertainties, questions of responsibility and conflicting objectives with other uses are slowing down implementation.

Smaller cities such as Solingen or Graz show that a lot can be achieved even with limited resources – provided there is the political will and interdisciplinary cooperation. It is crucial that drainage is no longer seen as “invisible” infrastructure, but as a designable part of urban development. Only then will solutions emerge that intelligently combine technology, ecology and use.

Challenges, synergies and future trends: where are we heading?

As promising as the new technologies are, their implementation remains a challenge. Key problem areas lie in the interface between system logic and decentralization. Who is responsible if a private green roof does not work? How are maintenance, control and financing regulated when water infrastructures are distributed among many players? And how can it be ensured that decentralized measures actually contribute to the resilience of the overall system?

The answer lies in new governance models. Cities are increasingly developing guidelines, funding programs and legal instruments to clarify responsibilities. At the same time, digital tools are being developed to facilitate monitoring and control. Urban data platforms, sensor technology and geo-information systems are becoming indispensable in order to record and meaningfully integrate the multitude of decentralized measures. The city of the future will thus become a digital, learning organism – provided that the database is correct and all stakeholders pull together.

Conflicts of use are another issue: where water is held back, it sometimes gets wet – which is not always compatible with the desired use of a square or park. Creative solutions are needed here. Multifunctional areas that serve as playgrounds in everyday life and become retention basins during heavy rainfall are prime examples of this new planning culture. The trick is to combine technology and design in such a way that synergies arise – and no acceptance problems.

The legal framework also needs to be developed further. The adaptation of building regulations, the development of standards for rainwater management and integration into urban development contracts are decisive levers. The transformation can only succeed if law, technology and planning go hand in hand.

Last but not least, the social dimension should not be underestimated. Visible water in the urban space, temporary puddles or flooded areas require a new understanding of urbanity. This calls for communication, participation and education. The urban drainage of the future is not just a question of technology, but also of acceptance and social learning.

Outlook: Digitalization, data and the future of urban drainage

Hardly any other area of urban development is currently benefiting as much from the digital transformation as urban drainage. Data-based systems, intelligent sensor technology and simulations are opening up completely new possibilities. Digital twins – realistic, dynamic city models – make it possible to simulate the effects of rain events in real time, evaluate measures and develop scenarios. The control of retention basins, the monitoring of reservoir levels or the optimization of green roof irrigation are thus becoming data-driven disciplines.

But digitalization is not an end in itself. It only unfolds its potential if it is embedded in a smart overall strategy. The aim is to make sensible use of the wealth of data without losing sight of the complexity. Interdisciplinary teams that combine urban planning, IT, water management and landscape architecture are the key to success. This is the only way to create solutions that are technically feasible, of high design quality and socially acceptable.

A central topic for the future is the linking of urban drainage with other urban infrastructures: energy, mobility, green space management and climate protection. Thinking of the city as a system means creating interfaces and utilizing synergies. Rainwater can supply energy, be used for irrigation or improve microclimates – provided that planning is forward-looking and integrative.

Finally, digitalization also offers new opportunities for participation and transparency. Visualizations, interactive maps and open data platforms make complex interrelationships understandable and invite citizens to help shape them. The urban drainage of the future is therefore not only smarter, but also more democratic – provided there is a willingness to be open.

One thing is certain: The challenges are growing, but the tools are getting better and better. Those who focus on innovative drainage concepts, digital control and integrative planning now will make cities more resilient, more liveable and ready for the climate challenges of the coming decades.

Conclusion: The city is draining – and redesigning itself

Urban drainage is undergoing radical change. Central sewer systems and decentralized green-blue infrastructures now form a new, multi-layered network of urban water management. The paradigm shift from rapid drainage to intelligent storage, use and evaporation is in full swing. This creates challenges, but above all enormous opportunities for urban planning, landscape architecture and water management.

Those who understand the technologies, legal framework and social dynamics can not only protect cities from heavy rainfall and drought, but also make them more liveable, more diverse and more resilient. Drainage is becoming the driving force behind a new urban design in which technology, ecology and urbanity go hand in hand. With digital tools, intelligent concepts and interdisciplinary collaboration, the urban water future can be shaped – sustainably, innovatively and full of possibilities.