C2C building at the Zollverein colliery

Office building compliant with Cradle-to-Cradle standards

Recycling is of utmost importance in terms of conserving resources. This principle is also increasingly having an impact on the building sector. Until now, the materials for constructing houses and other buildings have been used in such a way that they are difficult to separate when the buildings are demolished, therefore making it impossible to reuse them immediately. The Cradle to Cradle (C2C) standards offer a climate-friendly solution that has now been used to construct an office building. In this case, particular attention was paid to integrating the innovative building into the grounds of the Zollverein complex in Essen, which is a protected UNESCO World Heritage site. The idea at the core of the C2C principle is to think in terms of entire product life cycles from the very beginning and to make careful use of resources so as to conserve them. With its new headquarters at the Zollverein complex, the RAG Foundation has created a lighthouse project in terms of climate protection for itself and for the RAG AG corporation.

1,700 office buildings are built in Germany every year. A large number of valuable resources, such as copper, aluminium, steel and plastics are used in their construction; these materials are extremely difficult to separate and cannot be recycled when the buildings are demolished. This results in an energy-intensive waste disposal process. The C2C principle offers an environmentally sound and climate-friendly solution to this problem, making it possible to immediately re-use the building materials. It also promotes the use of non-toxic construction materials. This approach has now been used for an office building in Essen. Amongst other things, the RAG group is particularly keen to develop and revitalise former coal mining areas and industrial brownfield sites. At the same time, the company takes its social, ecological and commercial responsibilities very seriously, linking new projects with climate-friendly and sustainable concepts. This is what happened with the C2C building belonging to the RAG Foundation and RAG AG, which is situated on the land where the coking plant formerly stood at the Zollverein Colliery and was constructed in collaboration with other project partners. The future-oriented structure not only accentuates the energy transition in its interaction with the historical site. From here, the two companies bring together all the activities that they undertake in the post-mining era.

Engine for progress:

  • Lighthouse project for construction based on the principles of the circular economy
  • Conserving resources when constructing buildings by using the C2C approach
  • Use of renewable energy for the power supply
  • Development of an innovative material passport for buildings
  • Use of non-toxic building materials

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Photo: Thomas Stachelhaus

Zollverein: the headquarters of the RAG Foundation and RAG PLC are located at the intersection between industrial heritage and natural landscape. The office building was constructed in compliance with the latest sustainability standards on 9,200 square metres of building land.

A recycling cycle for climate-friendly building construction

C2C is based on three fundamental ideas in particular: firstly, waste is generally considered to be raw material, which can be used as a resource for new products or manufacturing processes. Secondly, the energy needed should be supplied from renewable sources and, last but not least, diversity should be promoted. The latter includes both biodiversity and cultural, social and conceptual diversity. In order to live up to these principles, the construction materials for the office building on the Zollverein colliery site were selected appropriately, the energy supply was designed in a future-oriented way and indoor areas were planted with greenery to improve the indoor climate. Single origin, recyclable floor tiles and certified floor covering, a façade that is also certified with recyclable insulation, halogen-free cables and pipes and recyclable glass doors turn the building into an innovative pioneer. The multi-purpose roof garden not only serves as a place to relax: the photovoltaic pergola generates around 80,000 kilowatt-hours of renewable energy from sunlight, and the rainwater collected here is stored in a tank and used for watering the roof garden as well as for flushing the toilets in the building. Special attention was paid to biodiversity when choosing the plants so that they attract plenty of insects. Last but not least, bat boxes provide accommodation for these nocturnal residents. The accessible planted roof garden thus compensates for the piece of ground that is sealed off by the building project. The RAG Foundation has made a considerable contribution to climate protection with this design. As well as saving resources, CO2 emissions are reduced by using renewable energy and due to the fact that the building components will not require energy-intensive waste management.

Documentation and inspiration

The building was a pilot project in the course of the EU research project “Buildings as Material Banks (BAMB)” and the materials used were documented in a “Material Passport”. The information recorded here can be accessed if the materials need to be recycled in the future and serves as inspiration for constructors and firms producing alternative building materials. In this project, all the participants aimed to support the future of climate-friendly building construction and to establish a systematic move towards a building sector based on a circular economy.

Photo: Dietmar Klingenburg

“The Zollverein World Heritage site is increasingly developing into a powerful place in terms of innovation in the coal-mining district. It is an example of how something new can be created from what has gone before. The prospects for the Ruhr District are improving on a daily basis as a result of this kind of project.”

Bernd Tönjes, CEO of the RAG Foundation

Partners and sponsors

  • RAG Montan Immobilien GmbH
  • kadawittfeldarchitektur GmbH
  • DS-Plan GmbH
  • Zechbau GmbH