This master's thesis analyzes and redesigns the current performance design of the Main Library in Najran University campus, Najran, the Kingdom of Saudi Arabia (KSA) to achieve a completely energy independent and off-grid building. The research demonstrates the energy development in KSA, investigates and analyzes the project, and studies the energy systems. Climate data for Najran city was generated and analyzed in Climate Consultant 6.0. The research examines case studies from hot-arid climates that are responsive climatically. In addition, the energy generation and storage systems are calculated and specified to the building and its site; Quick Energy Simulation Tool (eQUEST) was used to analyze and simulate the energy use in the existing building. Furthermore, Revit software was utilized to develop the project design and simulate daylight intensity for indoor and outdoor spaces. Additionally, Cool Vent simulated the natural ventilation for the building for the low-energy performance case and the high-energy performance case, and direct passive evaporative cool towers were simulated in COOLT software. Appropriate building envelopes, passive cooling strategies, and native landscapes are applied to the off-grid case. Solar power generation outcomes, wind turbines output, batteries size are optimized in HOMER energy simulation software; thus, this off-grid building generates electricity more than its use, then, stores the extra energy in batteries banks. Through this research energy independency was accomplished with a reduction in total energy consumption by 64%, and human thermal comfort levels were attained in the proposed design.