Refractories are used in a variety of processing industries including the ceramic, steel, aluminum, metal casting and heat treatment industries. Refractories provide thermal insulation, and do so by providing stagnant or "dead" gas space, namely, they contain a large volume fraction of voids. The prime criterion for material selection is refractoriness (i.e. use temperature) and the dimensional stability. One key property required for insulating refractory qualification is the service temperature limit (STL), which is related to composition, sinterability at use temperature, sintering temperature, and void volume. During the past ten years nano-pore and nano-scale fractal refractories have become available which are possibly significantly less toxic when compared to fibrous refractories. The materials used in fractal refractories are discussed in this article. Apart from use as high temperature thermal insulators the new class of materials are also finding use in a variety of products and applications of structural components such as nano-pore high performance coatings, sensors, filters and membranes used in the electronics, aeronautics, space, energy, and biomedical engineering fields.