The paper introduced the work done by Working Group 3 in the field of the research COST TU0701 "Improving the Quality of Suburban Building Stock". The main aim of Task 6 of the Action “Quality assessment models and protocols” developed by Working Group 3 in the two last years of the TU0701 COST Action, was to analyse the suitability of existing and available models for assessing the quality and value of suburban housing estates to be refurbished. The suitability of the models was checked taking into consideration their compatibility with the legislation (i.e. fire protection, earth quake prevention, emission thresholds), and the relevant standards of participating countries. The strategic aim of this Task was the definition of criteria, strategies and actions (procedures, technical tools, economic analysis) for receiving information about the actual degradation state of the buildings and the possibility to develop renovation plans, taking into account the appli-cability and availability of existing systems. The main objective of the Action is the development and dissemination of knowledge and tools to assess and promote the refurbishment of existing suburban building stocks” (Memorandum of Understanding COST ACTION TU0701).The main aim of this work is to compare systems and learn from each other the potentials of each methodology.