This project is an intervention of analysis and decision: analysis of former interventions and decision of tracing a new path by subtracting/aggregating distinctive elements in a formal symbiosis of significance, scale and materials. The subtraction of layers brings the stone back to the surface –solemn act of the beginning of works. This return to original expression led to a contemporary intervention on elements that couldn´t be changed: as so, the aggregation of a steel skin patina -Corten- in the bell tower and in the eastern/southern elevation volumes conferring maturation over the year