As a result of increasing population and buildings construction in Saudi Arabia, the demand for electricity is growing rapidly. There should be a greater focus on buildings in the kingdom and several methods should be applied in order to reduce energy consumption and create a lower carbon economy as residential buildings account for about 70 percent of the total consumption. This paper shows the importance of selecting the right, locally available, construction materials for the external wall and thermal insulation in reducing energy consumption for the cooling load, by 59% after using the most appropriate construction materials for Saudi climate.