The observability techniques have been proposed to deal with structural system identification under static loading tests. Up to now, this method has only been analyzed from a symbolical point of view. Despite the elegance of this approach, this mathematic analysis is far from being applicable in actual structures. To fill this gap, this paper presents a new observability procedure that combines both a symbolical and a numerical approach. To illustrate the potential of the proposed method, the observability technique is compared with two alternative methods presented in the literature. This comparison shows that, unlike to other analyzed methods, no information from the undamaged structure is required. Furthermore, the number of measurements required to be measured for damage detection is significantly reduced.