Concrete is a vital construction material renowned for its strength and durability. Compressive strength, a pivotal factor, determines a structure's capacity to endure loads and external forces. In the context of residential buildings, upholding structural soundness and safety aligns with adhering to the National Building Code (NBC) and approved construction criteria. Nevertheless, assuring the specified concrete grades has been neglected, raising concerns about concrete quality and strength in Nepalese residential structures. This study aimed to assess concrete compliance in Vyas Municipality's residential buildings according to NBC norms. We conducted both non-destructive testing (NDT) using rebound hammers and destructive testing (DT) on 7- and 28-day cured concrete samples to gauge their compressive strength. A correlation between rebound numbers and compressive strength was established, facilitating on-site strength estimation. The finding revealed robust connections between rebound numbers and concrete strength, with correlations of 89.3% and 93.3% for 7 and 28 days, respectively. This predictive capability endorses rebound numbers as a rapid quality assessment method. To enhance concrete quality and structural safety in Vyas Municipality's residential structures, this research proposes employing a linear regression model, encouraging concrete testing, enforcing strong monitoring and compliance, promoting education, mandating testing, and rectifying improper concreting practices.