Energy is a vital necessity for the growth of a modern technology. Energy consumption steadily increases due to increased population, improved modern life and increased industrialization. Residential buildings consume considerable amount of energy in any country. The thermal design of the building envelope is gaining wide importance to control the energy consumed
by the buildings for maintaining comfortable indoor conditions. Proper design of envelop is found to decrease the unwanted heat gain from 5 to 50%, depending upon extent of envelop design and selection of appropriate materials.

Key words: Thermal Performance,Wall, Roof, Buildings, heat gain, U-Value, Solar Design