PURPOSE: To prevent the generation of dew condensation positively by utilizing the advantage of simplicity on the execution of work and the security of simple fire resistance in a framework construction method, adopting an external heat- insulating system and installing an internal permeable layer and an external permeable layer on both sides of a heat-insulating material while holding the heat-insulating material.

CONSTITUTION: A heat-insulating material 51a is disposed in tension in the surface direction while interposing first furring strips 50a arranged outside a board 31 mounted on the outdoor side of a wall framework 24, in which an upper frame 26 and a lower frame 27 consisting of a base material and a vertical frame 28 are assembled in a vertical latticed shape, at intervals, thus forming an internal permeable layer 52a. A facing material 55a is disposed in tension in the surface direction while interposing second furring strips 54a distributed outside the heat-insulating material 51a at intervals, thus forming an external permeable layer 56a.