Modeling and measuring urban sustainability in multi-criteria based systems - A challenging issue

This paper addresses how urban sustainability is modeled and the ways criteria-based systems deal with its measurability for an effective and reliable assessment. Twelve sustainability models are reviewed and a subset is briefly presented. More importantly, this research work investigates five national rating systems of sustainable urban development compared with the newly developed CAMSUD system. The comparison focuses on the systems' structure, categorization, technical content and measurability. The main findings about the selected national rating systems thoroughly discussed in the paper are: (i) They all have a tree-like structure, (ii) their conceptualization and categorization follow three or four sustainability pillars models, sustainability topics or spatial scale; (iii) they use either planning-oriented or performance-oriented weighting approaches; (iv) the criteria are defined as sustainability goals, action measures or assignments to be fulfilled; (v) the sustainability items can hardly be juxtaposed since they are differently handled, (vi) overlapping criteria might occur, (vii) similar criteria can be categorized under different categories and this affects the emphasis put on these categories, (viii) all criteria are independently rated with no consideration of mutual interrelationships. In an attempt to solve some of these weaknesses, the newly developed CAMSUD system is introduced as alternative and relies on the following: (i) the system structure is considered as a network, (ii) the conceptualization and categorization is based on spatial scaling as well as on sustainability topics and pillars, (iii) many criteria are directly planning-relevant (23 of 40), (iv) the criteria are defined as sustainability goals rather than action measures and (v) the quantification of criteria is planned as to account for mutual interactions.