The present paper aims to explore the current energy performance of the existing housing stock of Greece while also examining the energy performance of buildings that have undergone refurbishment since the passing of the Energy Performance of Buildings Directive in 2010. A literature review of energy performance legislation and previous surveys are compared to data obtained from 400 dwellings with Energy Performance Certificates for the Thessaloniki and Naousa cities. A total of thirteen case studies of dwellings that underwent energy upgrade refurbishments were further examined (energy and cost) to draw conclusions in respect of their improvement. In order to further investigate how the energy upgrades affected the thermal comfort of the occupants, the thermal monitoring of three of the aforementioned dwellings were performed during the summer 2013. The owners of the above-monitored dwellings were also given questionnaires which investigated their level of satisfaction with the result of the upgrades. Lastly an occupancy survey of inhabitants of the city of Naousa provides an overview of the energy status of the stock as well as the cost aspect of the upgrades. The answers from the survey also give an insight in the actions and the behaviour of the users within the environment of their homes.