Having natural lighting inside the building is one of the main strategies for saving energy and meeting the comfort requirements of users. Natural lighting design must be taken into account in the early stages of building design, as it is one of the most important decisions in this stage, and effective natural lighting design requires identifying several factors, including building orientation, sun path, design of envelopes, ceilings, and shading systems. The building envelope is the mediator between the interior and the exterior and thus greatly influences indoor climate, visual comfort and energy saving. Most of the restrictions affecting the building envelope change over time (weather condition - path of the sun. .)Climate change. User preferences. Noise - wind Traditional building envelopes offer a single, stable solution that fits with all possible conditions and cannot adapt to changing conditions. Nevertheless, technological innovations are opening up towards the development of a generation of adaptive (climate-responsive) building envelopes that have the ability to maintain the best building performance configurations. On the changing conditions. Engineers and architects are beginning to experiment with adaptive envelope solutions to control solar radiation and natural lighting. The growing interest in adaptive systems that reconfigure themselves to meet changing climatic conditions and user needs has led to the conceptualization of multi-functional envelopes (responsive and dynamic, in order to increase the responsiveness of shading systems and to reduce systems that operate mechanically. The aim of this research is to improve the performance of natural lighting with Taking into account energy efficiency by examining and evaluating responsive external shading systems in administrative buildings .)located in the classified regional climate of Cairo, Egypt (hot, dry desert climate