To build a house at low cost, allow the reuse of a support column and a sill, and facilitate rebuilding of a house.

A tightening plate 21 tightened on a surface of a foundation B, a support plate 22 arranged above the tightening plate 21, and a sill 10 having a connection member 23 for connecting the tightening plate 21 and the support plate 22 mutually are fixed on the foundation B underlaid on the ground S. A support column 41 fixed vertically on the sill 10 is attached to a column connection plate 31 provided on the support plate 22. A mounting hole 34 is formed in the column connection plate 31, a through hole 42 is formed in the support column 41, and the support column 41 can be simply attached to the sill 10 by fitting a tightening bar member 43 into the mounting hole 34 and the through hole 42.