<p>Spandrels between openings significantly govern the performance of masonry buildings during seismic events. The present study aims to investigate the effectiveness of thin steel stripes as a retrofit intervention on spandrels in a Nepali stone masonry building. To achieve this objective, the Finite Element (FE)- macro modeling-based numerical models were validated against reduced-scale experimental specimens, where realistic bonding was considered by utilizing solid elements for bolt connections. This was followed by a parametric investigation on steel stripe width (10–30&#xa0;mm), thickness (0.5–2.5 mm), and bolt diameter (4–8&#xa0;mm) at reduced-scale, which emphasized the requirement of an adequate bolt configuration towards effective retrofit performance. Then, a stiffness-based scaling technique, which relied on classical beam theory, was subsequently utilized to scale the steel stripe dimensions from its application on laboratory specimens to a full-scaled wall. Validated retrofitting details were thereafter implemented on a representative full-scale URM wall particularly at spandrels and their effectiveness was assessed through static non-linear analysis. The results revealed that inadequately bonded retrofit offered marginal improvement in base shear (3.17%), while compared to adequately bonded retrofit, which demonstrated superiority at the global level by enhancing the base shear capacity by 18.93%, postponing the peak resistance by 81.23%, and satisfactorily redistributing damage from weak spandrels to adjoining piers, suggesting that the strategy can be a viable option as a local strengthening approach for masonry buildings where full-scale interventions are challenging.</p>