In the field of material science, the term ‘nano’ identifies the scale of morphological transformations that occur at the measure of one billionth of a meter. A nanometer (nm) is excessively diminutive and impossible to register by the naked eye. And yet, every year, dozens of materials are invented and manufactured with properties engineered at this tiniest of dimensions. In the field of nanotechnology it is the material itself that is being designed and engineered rather than the architecture which contains it. Nanotech materials are synthesized and calibrated to perform at the highest degree of specificity. Yet most building products that have undergone morphological changes at the nano scale typically do not occasion a significant change in their form; notwithstanding possible changes in appearance when using smart surfaces, thermochromic, photochromic and other shape-changing materials. Hence, it will be argued that rather than having a significant effect on the visual and formal design of architecture, design at the nano scale has a substantial effect on the thermal dimension of architecture.