A capacitive sensor for monitoring stresses acting in a construction structure and having a multi-layer structure provided with an upper conductive layer defining an upper outer surface of the sensor. A lower conductive layer defines a lower outer surface. At least a first structural layer of insulating material is in contact with the upper conductive layer and at least a second structural layer of insulating material is in contact with the lower conductive layer. At least a first plate layer of conductive material and at least a second plate layer, of conductive material, and at least one dielectric layer is interposed between the first plate layer and the second plate layer to define at least one detection capacitor inside the multi-layer structure of the sensor. The upper and lower conductive layers jointly defining an electromagnetic screen for screening the detection capacitor against electromagnetic interference originating from outside the capacitive sensor.