One of the most debated issues today is to find innovative and cost-optimal solutions for
retrofitting the existing building stock adapted to the local market in order to assure the commitment for the 20-
20-20 EU policy. As the dwellings are responsible for around 70% of the total final energy use in buildings,
retrofitting these types of buildings represent a challenge for the next decades and also an opportunity for
implementing sustainable building solutions. The strategy of rehabilitation of the neighbourhoods made of
collective dwellings should be based on a holistic approach, which takes into account all aspects of
sustainability: environmental, social and economic, along technical and functional issues. This research paper
presents the initial findings and proposals of an extensive interdisciplinary approach that takes into account all
the pillars of sustainable development. The case study is a neighbourhood in Timisoara made of collective
dwellings from prefabricated blocks of flats built in the ‘80s with one of the models having the poorest living
conditions in terms of space and energy efficiency, 770 Model, widespread in Romania.