A large number of problems were noted in this building of almost 4,000 sq m, in particular cracks along the whole length of the expansion joints. After the problems worsened, renovation work was programmed, and the client was keen to rapidly enhance the monitoring of the building to ensure the safety of the pupils in the school. OSMOS sensors were thus installed to monitor any movements in the cracks. Set to trigger on 1mm of tension or compression, none of the sensors were triggered, which reassured the client with regard to the progress of any damage noted. If, however, one of the sensors were to be triggered, the client could choose to increase monitoring to make it continuous.