12.01.2026

Reversible urban planning – concepts for dismantling bad decisions

Building design

High-angle shot of a German city, taken by Markus Spiske with a Canon 5d Mark III and Leica Summicron-R 2.0/50mm (year of manufacture: 1981).

Deconstruction, reversibility, error culture – words that have long received little attention in urban planning. But the reality of urban development is erratic, full of surprises and, yes, also full of wrong decisions. What do you do when a new district has been planned without the need for it? When a traffic axis mutates into a barrier or a prestige project turns into a flop? Reversible urban planning promises new answers: concepts, instruments and strategies that not only identify wrong decisions in urban development, but also allow them to be elegantly and sustainably reversed. Who dares, wins – and sometimes you just have to have the courage to undo the wrong thing.

Definition of reversible urban planning and significance for sustainable urban development
Historical and current examples of wrong decisions in urban planning
Instruments, methods and legal framework conditions for demolition
Technical innovations: modular construction methods, temporary uses and digital planning tools
Role of citizen participation, governance and error culture in the reversible planning process
Ecological, economic and social effects of reversible measures
Challenges: Resistance, costs, complexity and political will
Comparison of European and international approaches
Perspectives and opportunities for urban planning of the future

Reversible urban planning: a paradigm shift for urban resilience

For decades, traditional urban planning tacitly assumed that built decisions were irreversible. Once high streets, shopping centers or residential districts had been built, they were regarded as manifestations of eternal planning certainty. However, since the 1980s at the latest – with the debates on the reuse of brownfield sites and the increasing sensitivity to undesirable ecological and social developments – it has been clear that cities are dynamic organisms. And where there is dynamism, there are also mistakes. The term reversible urban planning describes the approach of designing cities in such a way that mistakes can still be corrected – whether through demolition, conversion, unsealing or temporary solutions.

The relevance of reversible urban planning is greater today than ever before. Climate change, demographic shifts, technical innovations and rapidly changing lifestyles make it almost impossible to accurately predict urban developments for decades to come. Those who plan today for the day after tomorrow run the risk of miscalculating. The call for flexibility is therefore not a fad, but a necessity. Cities must be able to recognize and name undesirable developments and reverse them in a targeted manner. This is the only way to create real resilience – and the ability to react to new challenges before they become an existential problem.

But what does reversibility mean in concrete terms? It is not just about the technical dismantling of buildings or infrastructure. Rather, a comprehensive concept is required that integrates legal, financial, social and planning dimensions. A reversibly planned urban quarter, for example, relies on modular structures, flexible usage zones and long-term monitoring instruments from the outset. Ideally, temporary buildings, interim uses and participatory evaluation processes are established that make it possible to identify undesirable developments at an early stage and take countermeasures.

Urban planning is thus at the beginning of a paradigm shift. Instead of focusing on eternal finality, the processual nature of the urban environment is taking center stage. Planning is understood less as a “setting” and more as a continuous dialog between space, society and time. Mistakes are no longer demonized, but accepted as an unavoidable part of urban development – and seen as an opportunity to find better solutions together. Deconstruction becomes an option, not a defeat.

For planners, architects and city administrations, this means that reversible urban planning is not a capitulation to complexity, but an expression of a professional, learning attitude. It requires the courage to admit mistakes – and the ability to change course. After all, the most sustainable city is not the one that never makes mistakes, but the one that knows how to use mistakes productively.

Wrong decisions in urban development: causes, examples, lessons learned

Anyone who accompanies urban development professionally knows that wrong decisions are not the exception, but the rule. From the infamous urban highways of the post-war period to monofunctional satellite towns and deserted shopping malls – the history of urban development is rich in examples where ambitious plans failed to meet the needs of the population, economic developments or ecological conditions. The problem: classic urban planning mistakes are usually big, expensive and long-lasting. Correcting them requires considerable effort – technically, legally and financially.

Stuttgart provides a prominent example with its elevated road on Österreichischer Platz. Celebrated in the 1960s as a pioneering traffic solution, the elevated road became a symbol of a car-friendly city that sacrificed quality of life and urban diversity in the 1990s at the latest. It was only after decades of criticism and intensive participatory processes that the decision was made to dismantle it – including a costly redesign of the district. The history of Berlin’s Palace of the Republic, which was considered politically and functionally obsolete after reunification, is similarly spectacular. Its demolition was controversial, but ultimately unavoidable – a lesson in the political dimension of reversible urban planning.

But it is not only major projects that turn out to be bad decisions. Smaller measures such as incorrectly placed bus stops, oversized parking spaces or inflexible development plans can also become permanent problems. Typical examples are office districts that become deserted in the evenings and at weekends because no mixed uses were permitted. Or new development areas that can hardly react to changing residential needs due to overly rigid specifications. In many cases, undesirable developments are the result of planning myths, political fashions or false assumptions about social trends.

Reversible urban planning takes these experiences seriously – and tries to learn lessons from them. This includes focusing on flexibility and adaptability from the outset, for example through variable floor plans, shared infrastructure or multifunctional open spaces. At the same time, monitoring, evaluation and error communication are essential components of a reversible approach. Only those who are prepared to regularly review their decisions can take countermeasures in good time before small mistakes turn into major problems.

The most important lesson from the history of urban mistakes is therefore simple but effective: lasting quality is created where planning is understood as an open, learning system – and mistakes are not seen as failures but as an invitation to improve.

Instruments, methods and innovations for dismantling urban mistakes

How can wrong decisions in urban development actually be reversed? What instruments and methods are available to planners, local authorities and investors today? The spectrum ranges from classic demolition and conversion measures to innovative construction methods and digital tools that simulate and evaluate demolition scenarios. The central principle here is the creation of flexibility – both in construction and in use.

Modular and temporary construction methods play a key role. Buildings consisting of prefabricated elements are easier to dismantle, convert or adapt to changing usage requirements. Temporary buildings – such as pavilions, container solutions or mobile infrastructures – are designed from the outset for limited periods of time and can be dismantled without great effort. In the design of public spaces, reversible elements such as mobile seating, flexible greenery or temporary art installations also offer the opportunity to react to changes without permanently interfering with the building fabric.

Digital tools are playing an increasingly important role: planning software, GIS systems and urban digital twins make it possible to run through demolition scenarios in advance, simulate the effects on climate, mobility, the economy and social issues and make informed decisions. Participatory tools that involve citizens and stakeholders in the development of possible dismantling options at an early stage are of particular interest here. This not only creates acceptance, but also valuable local knowledge that can be incorporated into the planning process.

Legally, demolition measures are often complex. They require adjustments to development plans, approvals, compensation regulations and often also political negotiation processes. Instruments such as urban development contracts, demolition requirements or temporary rights of use can help to create the necessary flexibility. An international comparison shows that countries such as the Netherlands or Denmark already have innovative legal models that facilitate demolition – for example, through “usage windows” or “real laboratories” for experimental urban development.

Finally, financing and economic efficiency are of central importance. Deconstruction costs money – but investments in reversible planning pay off in the long term. Studies show that flexible neighborhoods that can react to changing conditions are not only more resilient, but also more economically successful. Funding programs, partnerships with the real estate industry and innovative business models can facilitate deconstruction and make it an integral part of sustainable urban development.

Public participation, governance and a culture of error: the social dimension of reversible urban planning

Reversible urban planning is more than a technical task. It is a question of governance, participation and a culture of error. After all, it is not only the right method that ultimately determines the success of the demolition, but also the acceptance and commitment of the urban community. Those who openly address wrong decisions, involve stakeholders at an early stage and establish transparent processes can turn deconstruction projects into genuine learning processes – with added value for all those involved.

Public participation plays a key role here. Demolition and conversion often affect sensitive locations, established neighborhoods or controversial projects. Participatory planning processes – from workshops and participation platforms to urban labs – ensure that different interests become visible and negotiable. Participation not only increases acceptance, but also introduces new ideas and perspectives into the planning process. Formats that enable genuine participation and present demolition not as a defeat but as a joint new beginning are particularly successful.

Governance issues are closely linked to the ability to correct mistakes. Cities need structures that make it possible to openly name and correct undesirable developments – without losing face or political blockades. This includes clear responsibilities, independent evaluations and a culture of dealing constructively with mistakes. In many countries, so-called “urban redevelopment managers” or “change agents” are deployed to form interfaces between administration, politics and civil society and coordinate deconstruction processes.

An open culture of error is perhaps the most important prerequisite for reversible urban planning. Those who taboo mistakes block innovation. Those who see them as an opportunity to learn, on the other hand, create space for creative solutions and sustainable development. International role models such as Copenhagen or Rotterdam show that a relaxed, pragmatic error culture can become the hallmark of modern urban development – and even turn deconstruction projects into a driver of innovation.

Ultimately, the social dimension of reversible urban planning is a plea for more courage, openness and dialog. Mistakes are inevitable – the decisive factor is how cities deal with them. Those who see deconstruction as an opportunity can shape the city of tomorrow together – flexibly, sustainably and vibrantly.

Perspectives and challenges: The reversible city as a model for the future

Reversible urban planning is neither a panacea nor an end in itself. It is a complex, demanding concept that requires technical know-how, legal innovations and social commitment. Nevertheless, the number of cities that are setting out to reverse undesirable developments and make flexibility the guiding principle of their planning is growing. The future of the city does not lie in avoiding mistakes, but in the ability to manage them creatively.

The greatest challenges lie in the complexity and cost of reversible measures. Demolition is expensive, time-consuming and often politically controversial. Investors, administration and the public have to be convinced, compromises have to be found and new business models have to be established. At the same time, in many places there is a lack of legal and financial instruments to implement dismantling projects quickly and efficiently. The federal, state and local authorities are just as much in demand here as the real estate industry and civil society.

Another obstacle is the lack of standardization of reversible construction methods and planning processes. While modular architecture, temporary uses and digital twins are being tested in pilot projects, there is a lack of nationwide strategies and binding guidelines. The reversible city remains an experiment in many places – but this is precisely where its potential lies. Those who dare can win, fail – and learn from it.

The international perspective shows that reversible planning and building is no longer a utopia. Cities such as Amsterdam, Copenhagen and Helsinki rely on experimental neighborhoods, flexible mobility solutions and adaptive open spaces that can be continuously adapted, converted or dismantled. In Germany, Austria and Switzerland, too, more and more projects are being developed that see reversibility as a quality feature – from the flexible use of former airport sites to the conversion of inner-city parking garages into living space.

The reversible city is therefore not a static goal, but a process. It requires the courage to change, openness to new ideas and a strong culture of error. If these principles are anchored in planning, cities can be created that are not only resilient and sustainable, but also human and vibrant – despite, with and sometimes even because of the mistakes that happen along the way.

Summary: Reversible urban planning marks a fundamental shift in the way urban development sees itself. It recognizes the inevitability of wrong decisions and makes their correction an integral part of sustainable planning. With modular construction methods, digital planning tools, participatory processes and an open culture of error, cities are created that remain flexible and adaptable – even if forecasts do not materialize. The challenges are considerable, but the benefits are great: those who make reversibility a maxim not only become more resilient, but also more innovative and more liveable. Cities that focus on deconstruction and conversion are better equipped for the uncertainties of the future. And they prove it: Mistakes are not a disaster – but often the first step towards a better city.

16.12.2024

Project

IBA Basel 2020 at a glance

Building design

IBA Basel Specialist publication from the G+L editorial team

With the end of IBA Basel Expo at the beginning of June 2021, the International Building Exhibition Basel 2020 officially came to an end and with it the first effective International Building Exhibition in the border triangle between Germany, France and Switzerland. Everything you need to know about IBA Basel can be found here.

With the end of the IBA Basel Expo at the beginning of June 2021, the International Building Exhibition Basel 2020 officially came to an end and with it what was effectively the first International Building Exhibition in the border triangle between Germany, France and Switzerland. A closing film now summarizes the goals and developments of IBA Basel 2020.

The IBA Basel was the first International Building Exhibition to address the topic of spatial planning in border regions. International Building Exhibitions are a special format for urban and regional development. They are a hallmark of national building and planning culture. For more than a century, these experimental fields have brought current issues of planning and building to the forefront of national and international debate.

The origins of the IBA Basel date back to 2008, when everything began with the so-called first “draft memorandum”. This was drawn up by the Department of Construction and Transport of the Canton of Basel-Stadt together with the Trinational Eurodistict Basel TEB. In 2009, the TEB worked out the challenges and opportunities of trinational fragmentation and published these in the 2020 development strategy “A Future for Three”. In the strategy, it identified the main spatial planning objectives of “settlement development”, “transport development” and “landscape planning” as well as the “interactions with the areas of economic and population development” and “governance” and “financing of major metropolitan projects”. In 2010, the political players in the region jointly proclaimed the Basel International Building Exhibition.

2020: 20 projects with the IBA Basel label

In the ten years that followed, the IBA Basel put the shared responsibility for the agglomeration into concrete terms in projects, buildings, infrastructure and landscapes and provided impetus for a cross-border culture of cooperation, in line with the official IBA motto “Au-delà des frontières, ensemble – Growing together across borders”. Under the direction of Monica Linder-Guarnaccia, the IBA in the border triangle saw itself as an instrument of change. From 130 project proposals, the IBA team and a large number of stakeholders from the administration and interest groups launched 43 cross-border projects. A total of 20 of these were officially labeled as IBA projects in 2020.

To the memorandum of the IBA Basel

The memorandum of the IBA Expert Council describes the basis for implementing an IBA in ten recommendations. Precisely because the IBAs have no fixed regulations, their significance for building culture and urban development in a regional, national and international context must be constantly reviewed.

About the IBA Expert Council

The IBA Expert Council supports and advises the current IBAs and ensures that the developments, structures and content of the IBAs are in line with the quality criteria set out in the Memorandum. It also accompanies the preparatory phases of the IBA initiatives. The IBA Expert Council was appointed by the Federal Ministry of Building. Read more about the Expert Council here.

The initial situation of the International Building Exhibition Basel was that of a fragmented agglomeration. The central IBA task was to harmonize the different submission rights, legal bases, internal administrative processes, decision-making powers and financing models of the three participating countries and, last but not least, to build up intercultural competence. This was no easy task and without an understanding of the different mentalities and hierarchies, the implementation of real cross-border projects on an equal footing with the other party would not have been possible. In the course of the IBA in the border triangle, a paradigm shift took place in cross-border cooperation between German, French and Swiss stakeholders. The border region grew together on a political, economic and cultural level during the IBA years.

A budget of twelve million euros instead of one billion

Getting there was an adventure and many a stone had to be cleared away. The IBA in the three countries had to work with the different cultural influences of the three countries, the economic discrepancy between the flourishing economic metropolis of Basel and the agglomeration and the bilingualism – German and French. Above all, however, financing was a constant problem. Despite the support of 27 financing municipalities, the available budget remained far underfunded. The IBA Basel worked with twelve million, while the IBA Hamburg received one billion euros.
The planned three-year financing of the IBA Basel office and its project development fund placed additional demands on the ten-year project throughout its entire duration. This also became part of a recurring search for consensus, added value and return on investment.

The IBA in the border triangle is not an architectural showcase in the traditional sense and has therefore been criticized several times in the past. According to critics, the lighthouse projects traditionally built for an IBA are missing. And yes, the International Building Exhibition Basel is not characterized by building construction projects. Rather, it defines a new era for the format of the International Building Exhibition itself. The background: unlike its predecessors – such as the IBA Stadtumbau in Saxony-Anhalt, the IBA See in Lusatia or the IBA Emscher Park – the Basel International Building Exhibition is not taking place in a traditionally structurally weak area.

The IBA of processes

The Basel region has been flourishing for decades with financially strong companies such as Novartis and Roche. The IBA in the border triangle did not arise out of an emergency situation. The challenge of the International Building Exhibition Basel was to establish a tri-national planning culture between more than 64 regional authorities and numerous private stakeholders over ten IBA years and to launch outstanding cross-border projects in a rolling process. The International Building Exhibition Basel is therefore an IBA of processes. This difference has not made it easy for it. In contrast to building construction projects, process innovation is difficult to present.

Out of 130, 20 projects prevailed

An International Building Exhibition puts social, future living environments up for discussion. It must have a message and this must be significant for other regions, it must be transferable. The International Building Exhibition Basel has shown internationally how measures to strengthen and develop a border region can be implemented together. The Basel International Building Exhibition shows how beneficial it is to take the needs of the other party into account. It has shown how participation and an interdisciplinary approach can increase project quality, even if they take more time and are more complex. The 20 labeled IBA projects together with the IBA project groups and the nominated projects speak for themselves.

IBA Basel closing film

The finissage on June 4, 2021 marked the official end of the IBA Basel Expo and with it the International Building Exhibition Basel. Together with the IBA Presidium, IBA Basel Managing Director Monica Linder-Guarnaccia invited guests to reflect on the findings of ten years of the IBA process and look ahead to the future development of the region.

Spatial planning development across national borders was the focus of the International Building Exhibition Basel. No IBA before the IBA Basel had ever dealt with this topic in this way. The special focus, objectives and developments of the IBA Basel are now summarized in a closing film for the IBA Basel 2020.

Garten + Landschaft provided information online about the projects, their creators and the IBA’s goals. The findings of the first cross-border International Building Exhibition in the border triangle of Germany, France and Switzerland have resulted in the publication “IBA Basel 2020. Crossing borders together” in German and French, which is well worth reading. Find out more here.

Our colleagues at Baumeister also celebrated with a special Baumeister issue on IBA Basel 2020 in May.

22.01.2025

Project

Observation tower at Lake Seljord

Building design

At Lake Seljord in the Norwegian province of Telemark, home to a sea monster called Selma, landscape architects and architects planned a “sea snake tower” as part of the “Seljord and its legends” project.

Building in a picturesque landscape is a delightful task. The planners set the scene, the landscape accentuates small buildings. On October 18, a new observation tower, the “Sea Snake Tower”, was opened on Lake Seljord in Norway. It is part of the Skiensvassdraget river system and the culmination of a series of landscape-based interventions placed around the lake as part of the “Seljord and its Legends” project by Feste Landscape Architects, Rintala Eggertson Architects and Springer Kulturstudio, all from Norway. The 15-meter-high tower opens up to the surrounding landscape at different heights. Viewing platforms on the various levels offer views of the landscape. The municipality of Seljord has just under 3,000 inhabitants and is located in the Norwegian province of Telemark. A sea monster called Selma is said to have been sighted for the first time in Seljordsvatn, a lake that lies partly within the municipality, as early as 1750. This is why the coat of arms of Seljord, developed in 1989, shows a yellow sea serpent on a red background. The creature in Lake Seljord is said to be between four and 50 meters long, have a horse or crocodile-like head and appear pitch black. There is also talk of a pair of front fins and humps. The projects of “Seljord and its legends” are documented in Topos 74.Buildings in special places are also the theme of the November issue of Garten + Landschaft. The magazine presents a selection of successful buildings as well as viewing platforms, towers, footbridges and bridges.

Photos: Dag Jenssen