PROBLEM TO BE SOLVED: To provide an exterior heat insulative and water retentive device of a building which improves durability by exhibiting the excellent heat insulative and water retentive properties and improves a living environment to realize energy saving of an indoor temperature adjustment, and further, of which the construction is simple, man-days can be reduced, and the running cost can be reduced. SOLUTION: A heat insulating and water retaining mat 1 is laid on the surface 51 of a roof floor 50 to impart a shading property and a heat insulation property and prevent deterioration of the surface 51 and a thermal expansion and a thermal contraction of a large elongation/contraction, to improve durability of the building and improve the living environment. Further, water supplied by a water feeder 2 is retained in the mat 1 to positively cool the surface 51 for a further good living environment by a synergistic effect by the endothermic action of a water cooling action of the retained water and the endothermic action by the evaporation heat. COPYRIGHT: (C)2004,JPO
