## 1 Introduction  
The study of the seismic global performance of buildings continues to constitute one of the main purposes of Seismic Engineering. Some of the last seismic disasters (Nepal 2015, Ecuador 2016, Italy 2016, and Mexico 2017) have once again revealed the inadequate performance of many existing buildings against the seismic action. In this sense, seismic design codes have usually been improved after each earthquake disaster, but old constructions have remained unprotected by new techniques. Nevertheless, poor behavior has also been observed in those buildings designed with recent seismic regulations [1; 2; 3]. At an urban scale, the seismic risk of a structure can be defined as the potential expected damage that may happen to it in a specified time frame of exposure [4]. This property is related to the seismic hazard (the probability of occurrence of a seismic event of certain severity in a specific site and during a determined period of exposure) and to the intrinsic predisposition of the building to be affected upon receiving the impact from a quake of a certain severity, expressed as seismic vulnerability. This parameter depends on the design and construction characteristics of the building (structural configuration, geometric form, ductility of the materials, etc. ), therefore constituting an independent factor from the seismic action. In some territories, such as the Euro-Mediterranean, the proportionally low frequency of seismic phenomena in comparison to other regions has often generated a decline in the social and institutional awareness of the seismic danger. This context has on many occasions driven to scant rigor in the application of the existing regulations and a somewhat lax attitude in the application of good practices of seismic design [5; 6]. Without doubt this situation raises the levels of seismic vulnerability in many urban areas and the expected losses in the event of an earthquake. In this sense, the seismic vulnerability evaluation of existing buildings can be carried out using Mechanical or Macroseismic methods [4]. Consistent with the recent philosophy of seismic design known as Performance Based Design, mechanical or analytical methods consider the seismic demand and the capacity of the building constructions according to its respective spectrums developed from a nonlinear dynamic study. Proposed initially in previous studies [7; 8], these methodologies allow for a comprehension of the structural behavior of buildings for each level of impact when they are exposed to a seismic action, even including the contribution of masonry infills in the seismic response of a building construction [9; 10; 11]. Moreover, macroseismic--or empirical--methods allow for the performance of a specific building to be characterized based on a statistical analysis of observed damage during past earthquakes. From a series of characteristics related to the typology and the structural design of each building, these models estimate the seismic susceptibility according to vulnerability classes, through descriptors or qualitative variables [12; 13], or according to vulnerability indexes by means of a numerical valuation as a result of the quantification of the above-mentioned parameters. These methods include the Italian Method [14], the Japan Method [15], NZSEE and US Guidelines [16; 17], the Vulnerability Index Method [18], or recent European Commission reports [19]. For seismic risk assessment in urban areas, the RISK-UE Project [20] stated two methodologies. The first one, named the Level 1 method (LM1) and obtained from empirical procedures, typifies the seismic danger of an urban area according to the European Macroseismic Scale (EMS-98), and the vulnerability of the buildings through a vulnerability index developed in line with the Vulnerability Index Method. The second one, named as Level 2 method (LM2), models seismic action using the corresponding spectrum of demand and the seismic vulnerability consistent with the capacity spectrum of the structure [21].