To unify an effective dimension and increase the degree of freedom in the combination of unit houses, by arranging walls on the module center, when combining a plurality of house units formed as boxes to constitute a unit house.

A figure (p) obtained by dividing a module number P by an integer is set as a basic length and a side length on the plane-projected face of a house unit is set as a multiple of integer of the basic length (p). One of the contacting sides of two house units is arranged to coincide with the module center (m) and the other is arranged so as to separate from the module center (m) by a distance (d). In this way, the wall is formed at the side arranged to coincide with the module center (m) and as a result, the wall of the whole unit house can be formed to coincide with the module center (m). Hence, the indoor effective dimensions of respective units can be unified.