Germany uses so many resources each year that it would take three Earths to sustain its consumption.
July 24 2025, marks Earth Overshoot Day, the date when humanity will have used up all the natural resources that the Earth can regenerate in the entire year of 2025. The calculation of this symbolic date highlights the point at which we have consumed all the natural resources that the planet can sustainably provide within one year.
This situation creates urgent pressure to act, in order to stay within the planet’s ecological limits. To achieve this, it is necessary to reduce and reuse resources in product manufacturing. Circularly designed products, which prioritize durability, repairability, and resource efficiency, are becoming key ecological and economic success factors.
Key questions discussed during the Transformation Dialogue “Using instead of Owning” included: When does a circular business model become economically attractive and offer new opportunities? What framework conditions must be created to support this?
Welcome: Prof. Dr. Guido Spars, Founding Director, Federal Bauakademie Foundation
Moderation: Antonia Diel, Transformation Manager for Climate Change and Circular City at the Federal Bauakademie Foundation
The Federal Bauakademie Foundation invited four experts to discuss the topic:
- Ines Göbel, Zumtobel Group, Dornbirn, Österreich
- Antonia Görg, W. u. J. Derix GmbH & Co., Niederkrüchten
- Nora Sophie Griefahn, Cradle to Cradle NGO, Berlin
- Patrick Hypscher, Circularity e.V., Berlin
The video recording of the event will be available soon on our YouTube-Channel.
CONCEPTS OF THE CIRCULAR ECONOMY
Nora Sophie Griefahn, co-founder and executive director of the Cradle to Cradle NGO, introduced the Cradle to Cradle (C2C) concept as a pathway to creating a positive environmental footprint. Using a project from Venlo, Netherlands, she illustrated how designing buildings as material banks can offer not only ecological benefits but also economic advantages through residual value calculations.
At the C2C Lab, the NGO’s education center and office, a space and real-world laboratory has been established to demonstrate how circular construction can also be implemented in existing buildings. Griefahn emphasized that companies must fundamentally rethink their products—including logistics. Simply updating a product portfolio or adding a new business model is not enough. A circular economy also offers the opportunity to strengthen resilience in the face of increasingly uncertain supply chains.
Patrick Hypscher, consultant at Circularity e.V. and host of the podcast Circularity.fm, introduced the concept of Product-as-a-Service (PaaS), which also includes rental and subscription models. A PaaS model often proves worthwhile for products that have a high upfront cost and require frequent repairs.
He pointed out that while implementing a PaaS concept can lead to resource conservation, it does not automatically do so. This so-called rebound effect means that the intended positive environmental impacts may ultimately be outweighed by actual negative effects. As long as primary, fossil-based materials remain cheaper than secondary materials, circular business models often remain at a disadvantage — which calls for different pricing signals and the integration of environmental costs.
CIRCULAR BUSINESS MODELS IN PRACTICE
Antonia Görg, a civil and industrial engineer at Derix GmbH, shared the company’s experience transitioning from linear to circular practices in engineered timber construction. As a sustainability manager, she supports new business models (such as take-back obligations) and monetary incentives (like emissions trading) for the Derix Group.
Since 2021, Derix has voluntarily committed to taking back all products after their use and deconstruction. This unique commitment offers a significant opportunity to secure their supply chains amid the increasing scarcity of the raw material wood. Derix was inspired to introduce the take-back obligation by the “Circl” construction project in Amsterdam, Netherlands, where this requirement is mandatory. Circular planning - including detachable connections and the deconstructability of all trades - is essential for a successful circular business model. Antonia Görg also emphasized the need to develop new financing models, legal certainty, and standards to enable scaling.
In the awarding of the construction contract for the district archive in Viersen, the decree of the state of North Rhine-Westphalia was implemented, allowing “cost” as a selection criterion based on life cycle costs. This gave circular construction a price advantage over other competitors, as a residual value after deconstruction was factored in, along with the reduced costs related to environmental impact.
Ines Göbel, an industrial designer at Zumtobel Group, presented the company’s sustainability strategy and implementation experiences. With the introduction of internal Circular Design Rules, circularity can be tracked throughout every product development process, since deconstructability begins with design.
Through a pilot project, the Zumtobel Group gained valuable insights into the importance of careful disassembly – without which product reuse is rarely possible and scalability becomes limited.
Ines Göbel also pointed out that rental models currently do not offer a viable solution for municipalities and that a revision of depreciation logic is needed.
The panelists encouraged taking bold steps to get started, even if not all questions have yet been answered. They emphasized that knowledge is often gained during implementation and that mistakes should be viewed as learning opportunities. When building circular business models, it is crucial to deeply understand the needs of customers as well as downstream service providers, repairers, and deconstruction specialists to find the most promising model and avoid negative rebound effects.
© Federal Bauakademie Foundation, Photos: Anke Illing
