We explore the problems that discourage utilization of existing home. Next, we present the following housing policy plan to solve some of these disincentives relating to utilization of existing home in Japan. (a) Appropriate valuation of existing home using hedonic price function and disclosure of a soft with which people can evaluate existing home correctly. We made an economic model of valuation of existing home and showed how to delete errors in the process of calculation of evaluation of existing home. (b) introduction of latent defects insurance for existing home for sale ; and for the elderly, (c)support for utilization of the fixed term housing lease and (d) conciliation of next user of their home.