Residential buildings are affected by misuse, bad weather and ecosystems that cause gradual damage to the structural and architectural elements, which is evident in the coastal residential buildings. Many Communities resort to rehabilitating and restoring the signs of damage in these buildings using the same traditional materials used in their construction, which is considered one of the most negatively affecting the internal and external environment. This leads to energy consumption, which reduces the chances of sustainability, environmental damage, and depletion of resources for future generations, as well as the exorbitant cost of continuing to reach the required thermal comfort.

Since nanotechnology is of great importance because it provides a lot of nanometer materials with properties that contribute to improving the internal environment of architectural spaces. The results of the comparative analytical study between nanometer materials and traditional materials using the Design Builder simulation program showed a clear difference between them in energy consumption and thermal comfort events required in favor of nanometer materials such as glass, light nano concrete and easy-to-clean tiles because of their unique characteristics and capabilities that achieve sustainability, especially the energy sustainability standard. The Design Builder program was applied to the selected coastal residential area adjacent to the Bibliotheca Alexandrina and it was concluded that the use of nanometer materials is the most appropriate alternative in terms of energy consumption as one of the most important criteria for sustainability.