Circular construction and climate policy in Hamburg

In January, Circular Flanders travelled to Hamburg for the KARMA Interregional Meeting with project partners from Italy, Hungary, Romania and Germany. KARMA aims to strengthen local climate policy through concrete actions related to circular construction. Over the course of three days, we were introduced to innovative projects in construction, temporary use of space and the future of existing urban infrastructure. Hamburg has been promoting itself as a testing ground for urban transformation for several years now, and this working visit more than confirmed that. 

Innovative approach to heating in Speicherstadt

One of the most impressive visits took place in the historic Speicherstadt. This densely built-up district and UNESCO World Heritage Site is a complex environment in terms of implementing sustainable energy solutions. Nevertheless, Hamburg is working on innovative research related to efficient heat supply in old warehouses. Experiments with bio-based materials, natural ventilation and renewable energy are at an advanced stage. 
For regions such as Flanders, where the focus is increasingly on renovating and optimising existing buildings, this approach offers valuable insights. How do you modernise a historic district without compromising its heritage value? And how do you combine limited space with ambitious climate goals? Hamburg shows that it is possible, provided there is close cooperation between the city, researchers and real estate partners. The thorough, practical research contributes to technological innovations that entrepreneurs can put to use. 

With one foot in the past and an ambitious eye on the future, Hamburg is also known for large-scale new construction and urban renewal. The Hafencity is an example of a metamorphosis that has been going on for more than 20 years. The bar is set high: all projects must be sustainable and climate-adaptive, for example by complying with the Ecolabel. Recently, more attention has also been paid to materials, resources, and circular construction principles. Policymakers, project developers, researchers and architects in Hamburg take the German Bauwende seriously. One example of this is the Moringa project. This project is the first to apply the Cradle to Cradle principles on a large scale in residential construction. In practice, this leads to additional costs, questions about standards and longer lead times in implementation. Nevertheless, there is a great deal of enthusiasm among potential (social) tenants and buyers. 

Temporary use as a driver for circular innovation

We also visited inspiring initiatives involving the reuse or temporary use of vacant buildings. Firstly, this concerned a megalomaniac investment project that went bankrupt: can the abandoned shell in a prime location be completed in a circular manner and partly serve as a circular hub? The initiators united under the name Tower to the People and, as a grassroots organization, will sit down with investors and the city. Secondly, the pilot project in the borough of Harburg illustrated how an abandoned shopping centre can be given new meaning. It is part of the Interreg project CircleBim, which uses a BIM-driven approach to enable renovation or repurposing. In Flanders and Europe, hundreds of similar shopping centres from the 1960s and 1970s, with millions of square metres of floor space, are waiting for new ideas. 

These projects aim to go beyond mere 'temporary occupation': they serve as testing grounds for new functions, circular applications and social experiments, providing valuable lessons for future policy and design.

Learning across borders

Cooperation between European regions shows that each region has different challenges and strengths, but that we all benefit from practical knowledge to realise circular ambitions. Hamburg confirms that circular construction is not an abstract concept, but a daily reality that arises from experimentation and cooperation. 

With the KARMA project entering its final phase, almost all partners have succeeded in embedding the circular economy in their municipal or regional climate plans. With the finish line in sight, there are still political and geopolitical challenges to overcome. How do we maintain our ambitions? Will European regulations be implemented and how do we translate them into our own region? Are there sufficient resources to implement the proposed actions? These questions are also relevant in Flanders. Circular Flanders and OVAM therefore remain committed to bringing together stakeholders from waste policy, housing policy, circular construction and (local) energy and climate policy to make a difference.