The building automation system is defined as the operation of various building systems (eg lighting, air conditioning, fire fighting etc.) without the need for human intervention (or minimal human intervention) to control and control the internal environment and to ensure that it operates at the optimum level. The internal environment automation system features functional, administrative, environmental and other features, including increased user comfort, reduced operating and maintenance costs, improved control system efficiency and reduced power consumption, as well as increased user productivity. This study examines the effect of the automation system on performance within the buildings of engineering offices in Egypt. The problem arises from the absence of periodic follow-up and evaluation of operating systems, which leads to deterioration of its level. The research was designed to apply post-occupancy evaluation to office buildings. Post-work evaluation is defined as the systematic evaluation of newly constructed buildings after they have been in operation for at least one year to measure the extent to which the design objectives are achieved. The evaluation provides a way to collect data about the building and is of great importance to all participants in the user-to-user life cycle of the building and includes several measures such as thermal comfort, lighting, acoustics, Sick Building Syndrome (SBS) and others. The evaluation aims at raising the quality of the design, building and management, thereby enhancing the building environment. The research followed a joint strategy combining the descriptive study approach with a comparative analysis of the impact of the automation system by post-occupancy evaluation by conducting a questionnaire for two office buildings users, including the various aspects of evaluation in this questionnaire: internal quality of the environment, Productivity in work and architectural design. The research concluded that levels of satisfaction in non-mechanized buildings are moderate, compared with higher levels of satisfaction in the buildings operating automatically. The research also found that when using fully automated building, the possibility of personal control at different levels of the building must be considered. Automation system