A method of reducing the amount of cooling energy required to heat and cool a building is provided. The method includes disposing a porous insulating material in the exterior walls and substantially covering the ceiling in the attic space of the building to a substantial depth. The porous insulating material includes a desiccant. The method further includes permitting the desiccant—bearing porous insulating material to adsorb water moisture from the attic space and then permitting the adsorbed water moisture to desorb from the desiccant—bearing porous insulating material into the enclosed room of the building, resulting in a reduction in the amount of energy required to heat and cool the building.