Incentives and disincentives analysis for improving policy for seismic risk management of homeowners in Japan

In order to improve policy and programs to promote retrofitting of houses in Japan, incentives and disincentives for seismic risk management by homeowners were studied by two approaches: a fault tree analysis (FTA) method and a questionnaire survey to homeowners. The result of the FTA revealed two common causes that hindered homeowners' seismic risk management: disaster awareness problem and fear of dishonest contractors. The questionnaire survey identified both incentives and disincentives. It was observed that neighbors could prompt retrofitting statistically significantly, and there were three major disincentives to retrofitting: high retrofitting cost, low contractor credibility, and little engineering information. The current policy in Japan put emphasis on seismic diagnosis in comparison with those in the United States. However, based on the above-mentioned observations, it was suggested that planning and reviewing of retrofitting work, as well as management after retrofitting, should be assisted more comprehensively in order to promote retrofitting. In addition, more attention should be paid to risk communication to provide engineering information on retrofitting, to foster mutual trust between homeowners and contractors/engineers, and to encourage information exchange with neighbors.