Optimal design of residential building envelope systems in the Kingdom of Saudi Arabia

In this paper, a comprehensive analysis study is presented in order to improve the energy performance of residential buildings in the Kingdom of Saudi Arabia (KSA) through optimizing the building envelope elements. The building envelope energy conservation measures included in the study are wall insulation, roof insulation, window area, window glazing, window shading, and thermal mass. The optimization process was based on life cycle cost and energy savings. Optimum packages of energy efficiency measures for a residential building located in five climate zones in KSA have been determined for subsidized and non-subsidized energy costs. The results showed optimal energy savings of 39.5%, 33.7%, 35%, 32.7% and 22.7% for Riyadh, Jeddah, Dhahran, Tabuk and Abha, respectively, can be obtained for the subsidized energy cost case. For the non-subsidized energy cost case, the optimal energy savings were 47.3%, 41.5%, 43.19%, 41.1% and 26% for Riyadh, Jeddah, Dhahran, Tabuk and Abha, respectively. Moreover, a sensitivity cost analysis indicated that the cost of energy has more influence on optimal energy savings and life cycle costs than the initial costs of the energy efficiency measures. Finally, this study concluded that substantial savings in annual energy costs subsidies can be achieved by the KSA government if it aggressively promotes, through investments and incentives, energy efficiency programs for both existing and new buildings.