This study was set to identify any influence of eco-friendly certification on apartment prices and targeted areas which had many buildings with eco-friendly certification. The study classified high, medium and low areas according to the density of buildings and examined relations between prices and certifications for ranks of energy efficiency. The certifications had a positive influence on apartment prices only in high-densed areas, while not in medium and low-densed ones. As this study compared local influences according to the density of buildings across the nation, it is different from previous studies which have just known if eco-friendly certification had an effect on apartment prices on specific areas. On the basis of the results, the study presented directions of developments to private sectors and references to public ones in order to come up with measures for eco-friendly buildings.