How can we know which lifestyles are sustainable? How can we make our lifestyles sustainable? How can designers contribute to sustainable lifestyles? The PhD thesis "A sustainable level of material footprint" by Dr. Michael Lettenmeier, Consultant at the Wuppertal Institute, provides answers to these questions. It develops a benchmark for sustainable lifestyles: 8 tonnes of material footprint. This is only 20 per cent of the current Finnish average. "By applying the 8 tonnes benchmark, households were able to cut their Lifestyle Material Footprint by tens of per cents when redesigning their lifestyles," says Dr. Michael Lettenmeier.

The thesis shows what a sustainable lifestyle could look like and how the Lifestyle Material Footprint can help detect the critical factors behind our unsustainable lifestyles. For designers, the thesis has developed an orientation framework for Design for One Planet (Df1P). The framework provides numerous examples for sustainable solutions to be developed by product design, service design, infrastructure planning and communication design. "I hope, the thesis will inspire designers to adopt Df1P in their work," Lettenmeier adds.