Earthquakes across the world have highlighted the poor performance of open ground storey structures during a seismic event. The ground storey is kept open for the parking or other architectural planning requirements and is essential. Issue of parking space in urban areas is crucial for which the buildings with open ground storey are commonly constructed in these areas. Such structures are highly vulnerable to seismic force as observed during the past earthquakes due to formation of soft storey mechanism. In this paper, representative open ground storey building, designed as per prevailing guidelines is assessed for seismic performance, and is observed to be unsatisfactory. Demolishing such building which are satisfying the performance for gravity loads but failing to meet seismic requirements is not a sustainable solution. In order to improve the seismic performance, a strengthening strategy using steel braces at appropriate locations is evaluated based on the capacity curve. The results show strengthening of existing structures using the steel bracing system not only ensures the earthquake resistance but also extends the service life of buildings, which has a positive impact on the sustainability, with least disturbance to architectural planning.