Seaside houses in Kamoenai Village were seriously damaged by Typhoon No. 18 in 2004. The damage patterns were classified according to wave overtopping rate and the distance from the seawall alignment. The wave overtopping rate and wave forces on the houses were reproduced by two dimensional model tests, and the critical condition of seaside houses behind the seawall was shown as the function of offshore wave height and the distance from seawall. Based on the results, the evacuation condition was recommended for the coastal residents in Kamoenai Village. It was also confirmed that the safety of seaside houses can be improved by wave absorbing revetments in front of seawalls.