In many developing countries, numerous residential reinforced concrete frame structures are classified as non-compliant due to their inability to meet established standards. These structures frequently lack adequate transverse reinforcement at joints (referred to as unconfined joints) and are constructed with concrete of low compressive strength. In regions prone to earthquakes, such non-compliant structures face a significantly elevated risk of collapse. This study seeks to assess the reduction in seismic performance associated with various non-compliant features in reinforced concrete structures through numerical simulations. A two-story non-compliant structure from existing literature is modeled and analyzed under incremental horizontal load using ATENA software, and the results are validated against experimental findings related to the structure. The numerical analysis results show that non-compliant RC frame structures have an ultimate base shear value equal to 22% lower than code-compliant RC frame structures. Furthermore, the non-compliant RC frame structure has a more intensive cracking pattern on joints area than the code-compliant RC frame. This study proved that the non-compliant RC frame structure has poor seismic performance than the code-compliant RC frame. This result can provide practical contributions to construction workers by emphasizing the importance of anticipating non-compliant joint details to prevent potential damage and structural failure.