To base-isolate low-rise buildings of about one to three stories, mainly dwelling houses, and to rationalize a footing structure.

The surface 1 of the ground is rolled, footing parts 2 made of PC boards or the like are installed, and base isolators 3 are placed on the footing parts 2. A space truss 4 such that the number of lower chords 4a is 1 grid smaller than the number of upper chords 4b is mounted on the base isolators 3, with the apexes 4d of the space truss 4 installed on the base isolators 3. The corners of a building are installed on the space truss 4, and columns 5 and floor slabs 6 are placed. The space truss 4 used may have a spread in the form of a plane or may be made in a straight line or may be dotted. Floor slabs may be placed in place of the upper chords 4b of the space truss 4.