The building services industry has in recent years witnessed a resurgent public interest in energy efficiency building retrofits, largely owing to a confluence of global economic drivers (climate change, increased energy prices) that emerged in the late 2000s. However, much of this renewed global interest still contrasts with the Greek reality that hampers the achievement of energy efficient transformations in the built environment due to the current financial downturn. Consequently, given the inefficiencies of the existing Greek building stock, particularly, the highly energy consuming residential sector, the focus of this research is on mobilising the building retrofit applications in residential sector by exploring sustainable retrofit technologies and strategies germane to Mediterranean Greek environment. Such a study is important in order to determine the set of technologies that is technically, financially and environmentally favourable. In particular, the research approach adopted in this dissertation initially includes a multi-family and multi-story residence in the urban area of Attica as a case study and energy performance assessment of this building. Followed is the prioritization of the suitable retrofit technologies according to a set of competitive criteria via the multi-criteria decision analysis tool. The final step encompasses the optimisation process of retrofit technologies at a building scale which was accomplished by the development of five incremental potential retrofit options as well as appraisal of their financial feasibility. The findings of this research provide evidence that the building case study is rated as a highly energy consuming domestic building; more importantly, sustainable technologies towards Greek residential retrofit are being emerged by the prioritization process and finally, the incrementally designed five retrofit options are rendered financially feasible. The main conclusions drawn from this study highlight a new sustainable pathway for how a whole building retrofit approach could be applied to multifamily and multi-story apartment buildings that constitute the dominant characteristic of Greek urban cities. Apart from the tremendous energy saving opportunities and social benefits in the long run, this strategy offers great potential towards reviving the construction sector as the total retrofit cost could be distributed among residents and supported by new funding mechanisms to even shorten the payback period. Ultimately, recommendations as well as further steps for research and work are illustrated in order to remedy the inherent barriers to energy efficiency retrofit and most acutely, in multi-story residences, adopt the building retrofit market and encourage energy efficiency investments and behaviours via collective agreement in the built environment.