Résumé
The buildings of the 1960s are not designed for today’s conditions and sustainable buildingstandards. One of the solution strategies is renovation, which is not only for energyconservation but also for quality-of-life improvement. However, achieving both factors atonce is a challenge, mostly from a financial standpoint. For public establishments, theirpriority is on energy efficiency retrofits which in return could push the indoorenvironmental quality (IEQ) to the edge of the comfort zone. IEQ is correlated to thehealth, comfort, and performance of users according to previous studies. This paperpresents a case study of university buildings that underwent an energy-efficient renovation,including the replacement of windows and the installation of walls and roof insulation andmechanical extract ventilation systems. The objective is to analyze if the target energyconsumption is achieved while maintaining a good IEQ during the heating period. Using t-test statistics on in-situ measurements of the before and after renovations, the results haveshown three important findings. One, the total energy consumption has been reduced by67%. Two, the t-test shows a significant difference between before and after states, withtemperature decreased, and CO2 level increased. Three, a higher CO2 concentration is dueto a faulty ventilation control that provides half less of the initial design airflow rate to meeta healthy standard. Overall, both temperature and CO2 rates remain in acceptable rangesdespite the variation, but it is crucial to evaluate the HVAC controls after the renovation forsafety reasons.