In line with the Presidency Conclusions of the Goeteborg European Council, which emphasise the role of sustainable development for policy making in the EuropeanUnion, the project aimed at building a network of excellence that serves as a communication platform for researchers interested in modelling the transition to sustainable economic structures. The work was focused on (i) comparison activities to identify the comparativeadvantages of the models, (ii) the crucial role of stock-flow interactions together with endogenously stimulated technological progress and (iii) the socialand institutional dimensions of the transition process.Thus the project activities were expected to provide guidelines as to which economic structures are able to support to Union policies that generate economicwelfare without creating burdens on social, economic, and environmental resources.