"Sustainablility" in design is not a simple constrain that can be quantified and optimized in an engineering desing. Issues of sustainability are inherently complex and wicked; their assessment requires acceptance of this complexity and working with it. Each aspect (e.g. environment, society, regulations, design, materials...) can be explored in a systematic way but the integration of the aspects to give a final assessment needs judgment and reflection, as there is no one single sustainable solution to a problem. Integrating the different articulations of Sustainable Development needs a holistic approach and stakeholder participation. How can we teach this to engineering design students in an efficient and effective way?