This paper deals with the performance of a high school building renovated with prefabricated ventilated facade elements through a field experimental study under oceanic climate. Temperature, relative humidity and heat flux were measured at different points of the renovated facade, while temperature, relative humidity and CO2 concentration were monitored within a classroom. The performance of the renovated building is discussed based on the analysis of two years of measurement data. The experimental results show that the measured in situ thermal resistance of prefabricated ventilated facade elements could be evaluated reliably only under winter period and that it is higher than the design one. Secondly, we note that the application of exterior thermal insulation does not lead to major moisture related pathology on retrofitted building envelope. Only small mold growth risks may exist close to hygroscopic material in relation with solar radiation. Last, we observe that hygrothermal comfort is achieved most of the teaching time, whereas CO2 concentration exceed critical threshold levels every day. (C) 2019 Elsevier B.V. All rights reserved.