PURPOSE: To improve air permeability of an underfloor place by forming a layer, communicated to the open air, between an inner wall and a facing material, and forming a recessed part, extending in the direction of the length of a sill, in the under surface of a floor board disposed between floor joists located in a direction extending at right angles with the sill.
CONSTITUTION: Air permeable layers 8f and 8f communicated to the open air are respectively formed between inner walls 8b and 8b and facing materials 8e and 8e located to the respective inner walls. A space through which the inside and the outside of the inner walls 8b and 8b are intercommunicated is formed between the lower ends of the inner walls 8b and 8b and the upper surface of a sill 3. Floor joints 4... of a floor 5 formed such that floor boards 5b and 5b are engaged together between floor joists 4... are extended in a direction extending at right angles with the direction of the length of the sill 3, and recessed parts 23 extending in the direction of length are formed in the floor board 5b and 5b. The floor 5 is supported on the sill 3 so that the recessed part 23 is communicated with a space formed on the upper surface of the sill 3.
KASHIWA NAOKI
KOBAYASHI EITA
KOBAYASHI TOSHIYUKI
