PURPOSE: To form a space suitable for heat insulating, sound insulating and moisture preventing properties at the time of applying a finishing outer wall material such as a siding board and a panel board or laying a finishing roof material such as a roof tile and a galvanized sheet iron, and provide satisfactory working property in spite of this structure.

CONSTITUTION: On a plywood 1 formed into a quadrangle of standard dimension, supports 3 consisting of woody square timbers to be vertically used are juxtaposed at equal intervals and fixed to the plywood 1 to form a base composite material P. When it is nailed with the plywood 1 down in a guiding, and the supports 3 are then covered with a finishing outer wall material 13 or a finishing roof material 33, a vertically extending space 17, 37 easy to generate an air flow is formed by the supports 3 between the material and the plywood 1. In spite of the formation of such a heat insulating, sound proofing, and moisture preventing structure, the labor for mounting the supports 3 can be saved. An air permeable waterproof sheet 4 and a heat insulating material 2 may be applied above and below the plywood l, respectively.