The building and spaces shape have a great impact on indoor temperature. Well-Designed sun control and shading devices can dramatically affect indoor temperature. The thermal performance of internal spaces in hot arid desert is highly influenced by various passive design techniques, eg space dimensions, facade colors, fenestration ratio, glazing type; and vertical and horizontal shading devices. Simulation tools play an important role in taking decision during early design phase that could help in improving the thermal performance of buildings. The aim of this paper is to explore the impact of different shading devices on the thermal performance of residential buildings in Egypt. To achieve this aim of the research first, the climatic analysis of New Assiut City is introduced followed by identification for the prevailing residential prototypes within the city and the selected residential type. Second, the role of the used Performance simulation tool in enhancing the designs is highlighted. Finally, a simulation has been run for the selected residential site in NA City for the four principal orientations. The results of the study showed that the use of vertical fins have a indoor overhang reduced the temperature by 1.5 C for the temperature for the southern orientation.