One of the main objectives of the energy strategy of any country is conservation. Thermal insulation isof utmost importance in the context of energy conservation. Therefore, this study aims to optimizeinsulation layer for the ten cities of Turkey which have the highest number of laying hens. The yearlyheating and cooling loads were determined by using degree day method. Then optimum insulationthickness, energy savings, payback periods and CO2 emission were computed for Rock wool (RW) andGlass wool (GW) insulation materials. Results indicated that the optimum thickness of insulation forRW insulation material varies between 0.046 and 0.159 m, energy savings range between 35.42% and74.56%, and payback periods were between 0.67 and 2.00 years, while for GW insulation materialoptimum insulation thickness varies from 0.045 and 0.150 m, energy savings vary in the range of42.17% and 77.72%, and payback periods were between 0.61 and 1.72 years depending on the city, andtype of fuel. The lowest CO2 emission reductions (64.79%) were obtained for İzmir with natural gas andRW insulation material are used, while the highest value (88.76%) was achieved for Kayseri with LPGand GW insulation.