Retrofitting an existing building is one of the environmentally friendly solutions to 
reduce the dependency on constructing new buildings. There are huge numbers of 
existing building stocks that are suitable to be retrofitted such as historical 
buildings, offices, residential, warehouse, factories, vacant buildings and other 
historical buildings. However the retrofit process is still confronted by technical and 
social challenges. So we need to know how to make the best use of the public 
buildings in Egypt in sustainable way. In light of the anticipated relocation of the 
ministerial authorities to the New Capital city, more than 40 public administrative 
buildings in Cairo will be vacated and subjected to adaptive re-use plans. However, 
the available literature does not effectively help in terms of selecting the best retrofit 
techniques because energy efficient retrofitting is neither required nor widely 
practiced in Egypt. This paper presents a systematic approach to selecting and 
identifying the best retrofit alternatives for existing buildings. The generic building 
retrofitting problem and key issues involved in building retrofit investment 
decisions are outlined. There is also an overview of the research and development, 
as well as technologies of retrofit in existing buildings. This paper provides building 
practitioners and researchers a better understanding of how to undertake an efficient 
building retrofit to enhance energy conservation and sustainability. Furthermore, it 
highlights the significance of Building Information Modeling as a part of the 
retrofitting process.