In order to control the issue of global warming, some significant protocols are signed and precautionary proposals are prepared in Turkey and worldwide. In this context, efficient use of energy in buildings is quite essential for decreasing the greenhouse emissions globally, since building stock accounts for about 40% of total energy consumption. The codes and implementations are carried out by local and international authorities to ensure energy efficiency in building stock, where the public buildings are supposed to lead. Therefore, in this study energy efficient retrofitting of public primary and lower secondary school building stock is targeted through the proposed methodology. In the proposed methodology, firstly, a representative educational school building was determined among primary and lower secondary school building stock in the selected pilot area according to analyses of the educational buildings, and its energy model was done and calibrated via ASHRAE Guideline 14 by collected physical and energy performance data. Then, calibrated energy model was used to develop retrofit scenarios with control strategies, which were optimized through life cycle cost evaluation. Hereby, the methodology proposed a whole evaluation approach in which existing buildings are subject to have cost optimal energy retrofits.