housing prices have risen sharply since the Moon Jae-in administration, and in some areas of Seoul, the average apartment price has reached more than 1 billion won. Accordingly, as a real estate regulatory policy, the government introduced DSR following LTV and DTI, which are one of the financial loan regulation policies, and came up with a policy to suppress the increase in house prices through loan restraints. came up with However, the land that can supply housing on a large scale is limited and it is difficult to find suitable land at present. Although there is a way to supply new housing through reconstruction and redevelopment, the reconstruction projects of low-rise apartment complexes that are feasible have already reached the completion stage, and the remaining middle and high-rise apartments are turning to multi-unit housing remodeling projects rather than reconstruction due to lack of business feasibility. However, the target houses of the remodeling project are housing complexes that were built in a way that did not take into account remodeling in the past.