In this research paper, design strategies of retrofitting activities were evaluated based on specified district sustainability indicators. The main objective is to identify the existing conditions of the selected district within the scope of applied indexes to develop new strategies for retrofitting. The district is represented by 3 buildings with 20,000 m(2) conditioned area which contains similar building characteristics as remaining residential buildings in the city. Accordingly, energy models of selected buildings were created and analyzed where hourly dynamic simulation tool was used to assess energy indicators. The intention is to have detailed calculations of the energy index with reference to indoor comfort, greenhouse gas emission and the economical index with reference to return on investment. The findings of this assessment reveal a number of significant implications for the improvement of the overall building performance. The most explicit finding of this study is to show that 65% energy saving, correspondingly 69 kg/m(2)year greenhouse gas emission reduction with 5.16 years return on investment can be achieved by the well-defined and precisely calculated district sustainability indicators.