The thesis develops an analytical model for evaluating- the planning processes and outcomes of sustainable eco-city policy. The existing literature tends to consider the eco-city and sus-city models separately without acknowledging their individual contested nature and limitations. They do not provide a holistic view to explore the different contexts at the local city level.

An alternative perspective is proposed, drawing on the emerging philosophy and concepts of the eco-city and sus-city models. The research proposition is built upon a review of the relevant literature, analysing ecocity and sus-city concepts, and applying them to build an analytical model of a sustainable Eco-city. This framework allows for an in-depth understanding and evaluation of the planning processes and outcomes of sustainable eco-city policy with its four key principles of futurity, environment, equity and participation and covers the three themes inherent to sustainability: the environmental, social and economic.

Using a broad constructivist approach, the research aims to understand the knowledge claims of participants in order to examine the meaning of the sustainable eco-city and how its policy is deployed at a local city level. The proposed analytical framework is used to explore two cross-national comparative empirical case studies - Reading in the UK and Taipei in Taiwan. These studies demonstrate the value of the framework as an analytically robust and practical perspective which can aid our understanding of the planning processes and outcomes involved. The research found that the formulation and evolution of eco-city policy was clearly related to the four principles and that during this process a number of key factors shaped the policy and its implementation. These included historical, economic, institutional and political dimensions, some of which were influential in both cases whilst others were more specific to each city. In terms of policy outcomes, the picture is equally mixed with some of the policy initiatives making good progress whilst other have been undermined or deflected due to the influence of these general and specific factors. Certain suggestions are put forward to respond to these constraining forces.