To provide an opening wide enough for a basement window or a daylighting aperture, while taking the relation between the building body erecrted on a foundation and the basement into consideration and provide a good heat-insulation and waterproof function to the basement including the foundation and facilitate the plan of a building excellent in the design by taking the external appearance including windows into consideration.

A part of the wall (k) of a basement B is used as a foundation R and a building body T is erected on the foundation R. The building body T is provided with the first wall P1 extending from the foundation R to the floor 1F of the first floor of the building body T and the second wall P2 positioned at the upper part than the first wall P1. The first wall P1 is constituted of a different material from the foundation R.