## 1 Introduction  
The seismic performance evaluation of existing buildings is a fundamental aspect of seismic engineering. In Spain, as in many other European countries, a considerable number of reinforced concrete structures were built during the 1980s and 1990s, which often do not meet the technical requirements of current codes. In the past few decades, rules for seismic design in Spain have changed a lot to make buildings stronger against earthquakes. This change started in the early 1990s with the launch of the first full seismic building code, NCSE-94 (Norma de Construccion Sismorreissentente: Parte General y Edificacion) [1]. A major milestone was the introduction of the first comprehensive seismic building code, NCSE-94 (Norma de Construccion Sismorreissentente: Parte General y Edificacion), which ensured that building designs incorporated earthquake resistance, especially in seismically active regions. Before NCSE-94, Spanish construction practices adhered to less rigorous seismic guidelines set by earlier regulations such as MV 101 (1963) and PGS-1 (1969). These early codes offered only basic seismic recommendations and often left the consideration of seismic forces optional in low-seismicity areas, limiting their overall effectiveness. The implementation of NCSE-94 in the mid-1990s brought detailed prescriptions for structural design and construction, significantly improving seismic design standards. Subsequent updates, including NCSE-02 [2] and the Spanish Technical Building Code (CTE) [3], further refined these standards, imposing stricter requirements and enhancing construction quality and safety. Hospitals and other essential infrastructure are constructed with a minimum lifespan of over 50 years to ensure their functionality during and after seismic events. The hospital in Orihuela, built in 1988, adhered to the seismic regulations and building codes of its time, which were less advanced compared to those established post-NCSE-94. During this period, there were notable improvements in construction quality and materials, particularly in structural concrete, yet the seismic-resistant design was still evolving. Considering the date of the hospital's construction, it is crucial to assess its current seismic resilience against modern standards to determine whether retrofitting is necessary to meet present-day seismic requirements. Such proactive measures are vital for maintaining the hospital's operational integrity and safety during earthquakes. While several studies have evaluated the seismic vulnerability of health facilities on a large scale [4; 5; 6; 7; 8; 9], detailed assessments of individual structures remain infrequently documented. These evaluations are essential for all strategically important buildings. For example, [PERSON] et al. (2016) [10] carried out a seismic vulnerability assessment on an existing eight-storey reinforced concrete (RC) hospital building using both numerical analysis and field monitoring data. They introduced a method for developing \"time-building specific\" fragility curves and found that field monitoring data are crucial for precisely determining the building's condition, which might differ from initial assumptions based on design and construction documentation. The study concluded that the building might be more susceptible to seismic events than previously estimated. [PERSON] (2019) [11] outlined an innovative method for conducting seismic assessments of individual buildings, including healthcare facilities, by employing multiple independent computer models. [PERSON] (2015) [12] applied the pushover method to evaluate the seismic vulnerability of an irregular RC hospital building in Avezzano, Italy. The study explored the sensitivity of torsional inelastic responses to factors such as lateral force distributions, higher mode contributions, accidental eccentricity, and controlpoints for monitoring target displacement. [PERSON] et al.