To prevent a house from breaking or falling on an earthquake by a method wherein a foundation part is formed of a frame part and a mat foundation, and a foot extending in the horizontal direction is formed at the lower part of the frame part while reinforcements are arranged at the mat foundation.

A closed loop-shaped upright frame part 11 of a foundation part is formed of an aboveground part standing above the ground surface and an underground part extending under the ground surface. Reinforcements 13 are arranged inside the frame part 11 while a foot 12 extending in the horizontal direction is formed at the lower part of the frame part 11, and the foot 12 is placed on broken stones 60. Furthermore, a moistureproof film 16 is laid on the broken stones 60 laid at the inside of the frame part 11, and leveling concrete is made thereon with reinforcements 14 arranged lengthwise and breadthwise, and thereby a mat foundation 15 is formed. The frame part 11 is connected to beams of a house with long metal bolts 21. Therefore, the house can be prevented from tilting even in the case of liquefaction on an earthquake.