Analysis of the Post-Sale System Selection Attributes of Private Apartment Developers*

In South Korea’s private apartment market, the post-sale housing system has been applied only in a limited number of cases compared to the pre-sale model. Nevertheless, the institutional necessity of post-sale systems has been continuously emphasized, particularly in terms of consumer protection and construction quality assurance. However, because of the burdens related to project financing and heightened market risks, post-sale remains a difficult option for suppliers to adopt in practice. Against this backdrop, this study empirically analyzes the attributes that influence private developers’ decision to adopt a post-sale model. A random forest classification model is developed based on a survey of industry professionals involved in post-sale apartment development projects. To evaluate the importance of each attribute, the study employed both Permutation Importance and SHapley Additive exPlanations analyses. The results indicate that expected sales price, speculative area designation, and project finance loan interest rate are significant determinants of post-sale adoption. These findings suggest that to promote wider adoption of the post-sale model, policy efforts should focus on reducing supplier-side financial risks and enhancing profitability through institutional and financial support.