Thermal upgrade assessment of a multi-storey residential building based on in situ measurements

International audience; Within the framework of a renovation project in Stockholm area (Sweden), in situ measurements were carried out with the QUB/e method to (i) assess the actual thermal performance of the building fabric and (ii) validate the thermal upgrade measures implemented. Two consecutive QUB/e tests were performed in an apartment of a fully renovated multi-storey residential building. The average U-values were 0.64 ± 0.04 W m −2 K −1 and 0.25 ± 0.02 W m −2 K −1 for the glazings and the external walls, respectively. The measured values were in good agreement with the calculated values communicated by the municipality. A comparison of in situ measurements undertaken before and after the implementation of the thermal upgrade measures indicates that a threefold decrease of the U-values (i.e.,-67%) was achieved. This was consistent with the target set by the municipality (i.e.,-60%). The thermal performance of the building fabric resulting from the thermal upgrade measures implemented (using off-the-shelf solutions) could thus be considered validated.