Human activities and products are exceeding the biomass of our planet, while natural resources become scarce and additional emissions cause an imbalance in natural systems.
The proper use of materials is a prerequisite for Circular Design. This means, on the one hand, keeping renewable and sustainable resources, from planting to biodegradation, in the loop (Biological Cycle); on the other, the use of limited and non-renewable technical materials, which in the future will be recovered from products and kept in use (Technical Cycle), instead of the continued extraction of limited resources from our planet. The accumulated inventory of human activities then serves as the source materials for the production of new products.
Hence, a main goal of Circular Design is to develop products in such a way that biological materials find their way back to nature, while the value of technical mate- rials is preserved to the greatest degree possible.
With plastics, for example, we see that a few less polymers make it possible to create a local circular economy, which employs decentralized manufacturing techniques to manufacture new products from old materials.

Modularity and the separability of products into their components prove to be key principles in Circular Design. The possibility to replace or extend parts of a product ensures the long-term use of products as it involves the repair and maintenance, but also extension and improvement of products.
This is also the first step in the production of new products from existing components (Re-Manufacturing). The procurement of raw materials and production costs are thereby reduced. Hence, design innovations are required on the level of components, which ensure that the products remain attractive for a long time, can be adapted to technical developments, and be reintegrated into production processes. In the spirit of Circular Design, a task is to imagine multiple combinations of the components on hand and also future ones, and thereby develop new and open product systems.
Standardized components along with new technologies for local production facilitate adaptation to new requirements or may even empower users into becoming co-designers.

Products must be consciously embedded in systems to be circular. The design of product service systems accesses new consumption patterns and markets, which are based on services without compromises but also the conservation of resources. For designers, this entails the development of design concepts above and beyond product design, which accompany the product in its complete life cycle.
A multitude of users can benefit from new product service systems, while corresponding business models promise manufacturers a reliable income and customer loyalty. Moreover, when the product remains the property of the service provider, the path to the reuse of components and materials is short, and it is thus the manufacturer’s responsibility to close the loop.
Once the system – in which high-grade products, components, or materials stay in a loop – has been put in place by the manufacturer or in cooperation with partners, then even a shorter service life can fulfill the objectives of a circular economy.