This paper presents the results of a real-scale experimental work regarding innovative seismic retrofitting technique for masonry walls and vaults by epoxy-bonded composite strengthenings. Palazzo Elmi-Pandolfi in Foligno (Italy), an historical building dated 1600 that was seriously damaged in the earthquake of 1997, has been repaired and retrofitted including carbon FRP (CFRP) strengthenings, whose effectiveness has been evaluated through dynamic and static tests. Brillouin technology is an ideal complement for similar retrofit applications, since the low cost of the sensor makes monitoring all the critical areas rather affordable, while the distributed sensing feature allow to detect anomalies in load transfer between FRP and substrate and the location of eventual cracking patterns. Furthermore, Brillouin sensitivity to both strain and temperature can be used also to ensure that the glass transition temperature of the composite matrix is never approached. In this work, preliminary tests were performed in order to assess Brillouin monitoring effectiveness in real applications for strain monitorage and crack detection.