Rapid and reliable structural health assessment is crucial after earthquakes to ensure safety and informed disaster response. Structural Health Monitoring (SHM) has emerged as a more quantitative alternative, offering the ability to continuously monitor structures and detect early signs of damage. However, conventional SHM systems, which rely on dense sensor grids or costly fiber optic installations, face significant challenges in terms of scalability and cost-effectiveness. This study addresses these challenges by employing laser interferometry (LI) to convert the strain of fiber optic (FO) cables into damage-sensitive signals. Our approach reveals the preliminary feasibility of using LI with FO infrastructure in buildings to develop a scalable and low-cost SHM framework for damage assessment. By converting fiber signals into structural strains using interferometric techniques, the proposed approach bypasses the need for dedicated sensors. We demonstrate the potential of this technique through simulated and experimental results assessing the feasibility of real-world applications. This research aims to bridge the gap between the need for rapid damage assessment and the limitations of current SHM systems, offering a practical solution for large-scale implementations using existing FO networks.