An insulation structure for an appliance includes a cabinet having an outer wrapper and an inner liner, with an insulating cavity defined therebetween. A plurality of hollow insulating organic/inorganic spheres is disposed within the insulating cavity, wherein a secondary insulating volume is defined between the plurality of hollow insulating organic/inorganic spheres and an interior surface of the cabinet. The interior surface of the cabinet defines the insulating cavity. An insulating fill material is disposed within the secondary insulating volume, wherein the insulating fill material and the plurality of hollow insulating organic/inorganic spheres define a substantially uniform insulating material.