Mona Mijthab’s ecological sanitation system “Mosan” is being implemented in Guatemala in collaboration with families from Mayan communities. Photograph: Mona Mijthab

Annina Gähwiler, what is Circular Design?

Circular design endorses the goals of the circular economy rather than those of the linear economy. The latter is unsustainable and harms the planet by using cheap materials, cheap energy and cheap credit. Circular design is about avoiding waste, for example by extending a product’s life cycle. For a product to remain in circulation for as long as possible, it should lose neither its integrity nor its value. On the one hand, certain design criteria may be taken into account: Can the product be repaired or upgraded? Is it modular and can it be broken down into individual materials? Is it free of pollutants? On the other hand, circular design requires carefully selected business models and services such as rental, exchange, return, repair, reprocessing and recycling. Inspiration for circular solutions may stem from new technologies or the changing needs of society. It also involves exploring user experiences with the product. Circular design requires and promotes systemic, integrated thinking and counters the problems of global resource consumption with creative options for action.

One example of a project based on the idea of circulation is “Mosan,” an ecological sanitation system designed by Mona Mijthab. A mobile source-separating toilet improves hygiene conditions in informal settlements and poor areas. Faeces are regularly collected, treated and processed into fertiliser or fuel. Developed as a Master’s project at ZHdK, the social enterprise Mosan GmbH, founded on this basis, is now operating successfully in Guatemala.