Resources are becoming increasingly scarce ‒ There is a need to rethink our approach to urban planning

Giving waste a value

The need for implementing circular principles in construction was beyond doubt: the world’s rapid urbanisation means that more than four billion people are already living in cities today. As one of the world’s largest resource guzzlers, accounting for 50-60 percent of the world’s total waste, the construction industry will have to re-think its current linear model of consumption.

In the next 50 years alone, the number of new constructions will equal the total number of buildings built to date, according to Kasper Guldager Jensen, Senior Partner at 3XN Architects and founder and director of GXN Green Innovation in Copenhagen.

The circular economy provides a future-oriented alternative by facilitating the reuse of materials at their highest value possible, and ensuring that little to no waste is produced. Jensen explained how his studio approaches research, highlighting how digital processes and scalability now mean that materials previously regarded as waste are increasingly being brought back into the value chain as sustainable biomaterials.

Shaping a circular future together

Circularity faces many challenges in its implementation, nevertheless. Maja Johannessen, research analyst at the Ellen MacArthur Foundation, noted that the complexity of urban activity is one of the main barriers: not one single stakeholder is crucial for success, but successful implementation will require the collaboration of many actors from the private and public sectors.

Cities looking to go circular will need to implement a holistic approach and targeted co-operation. “We, as designers, as architects, as engineers, are all in the same boat,” said Arup’s Head of Research & Innovation Europe Dr.-Ing. Jan Wurm.

A cross-generational and inter-disciplinary approach will be essential for the construction industry. Young innovators need a suitable environment in which to implement innovations successfully; while larger corporations are often compelled to invest in sustainable measures in order to remain up to date, numerous start-ups already identify with circular principles. Together, they can develop economic and sustainable solutions promoting circular economy. Events like MakeCity or the Amsterdam WeMakeThe.City Festival, introduced by Eveline Jonkhoff, help building networks. As the City of Amsterdam’ Strategic Advisor for circular economy, Jonkhoff explained how policymakers can help promote circular principles, noting that supporting research facilities and a close cooperation with the private sector were decisive factors for success.

Economic efficiency is crucial

Bente Lykke Sørensen, Head of Housing and Building Development in the Danish municipality of Aarhus, said that circularity needs to be an economically viable initiative in order to attract investment.

However, according to Jörg Finkbeiner, architect at Partner & Partner in Berlin, the sustainability and innovation aspects of circularity could make it an attractive for private investors. After all, measures implementing circular principles are not experiments but pioneering projects.

“We are careful when constructing a building, but this care is still lacking when tearing it down,” said Wurm, noting the prevailing mentality in the construction industry. Building in circular thinking from the design phase of a project should become standard, said Andrea Klinge of ZRS Architects in Berlin, who called for the recycling of building materials to replace demolition.

Flexible building concepts

Flexible usage of a building would allow for greater longevity: exploring different utilisation of space through modularity, or with the simple addition of infrastructure such as stairs or lifts, could also counteract demolition. This flexibility can also be extended across buildings, to create a complex with new possible uses. This was one of the key issues highlighted by Oliver Schruoffeneger, district councillor for urban development, construction and environment in Berlin, who added that we are currently focusing on individual buildings when planning and realising construction projects. We need an understanding of the entire context.

Digitalisation strengthens the identity of materials

Keeping a detailed archive of all the materials used in a building is difficult. Material passports could create a trail of data that would help identify, locate and therefore re-use all of the materials used. Digitalisation would facilitate the creation of a materials cadastre, too, creating comprehensive records.

Our current linear consumption model means a material loses its value as soon as it’s disposed of and ends up as waste. However, Prof. Raoul Bunschoten from the Technical University of Berlin points out that the handling of all this data would also create a new problem. The required transparency and traceability entail a responsibility of handling the data is a task that has not yet been assigned to anyone.

Circular economy confronts the construction and real estate industry with a multitude of complex challenges. Continuously approaching these challenges enables the learning process in which we currently engage. Finding inspiration in nature’s self-organisation, in which no waste exists, could also help the construction industry move forward. The reuse and recycling of so-called waste offers the opportunity to decouple income from resource consumption, opening the door towards more affordable construction modes, where buildings and infrastructure blend into an urban ecosystem.

The symposium was organised by the international planning and consulting company Arup and the Berlin network dieNachwachsendeStadt. The symposium was moderated by Dr. Gereon Uerz, Head of Foresight Europe at Arup. Kasper Guldager Jensen, Senior Partner 3XN & Founder and Director of GXN Green Innovation in Copenhagen, gave an introduction to circular economy. The panellists were Jörg Finkbeiner, architect at Partner & Partner, Berlin, Prof. Nanni Grau, architect at Hütten & Paläste, Berlin, Prof. Dirk Hebel, Professor of Sustainable Building at the University of Karlsruhe, Andrea Klinge, architect at ZRS, Berlin, Dr. Jan Wurm, Head of Research & Innovation Europe at Arup, Berlin, Prof. Raoul Bunschoten, Professor of Sustainable Urban Planning and Design at the TU Berlin, Maja Johannessen, Research Analyst at the Ellen MacArthur Foundation, Isle of Wight, Eveline Jonkhoff, Strategic Advisor on the Circular Economy of the City of Amsterdam, Oliver Schruoffeneger, District Councillor for Urban Development, Building and Environment Berlin-Charlottenburg and Bente Lykke Sørensen, Head of Housing and Building Development of the municipality of Aarhus.