This article presents the calibration of a building energy model of a university building, developed using the Energy Plus simulation program, by comparing data monitored over the spring season, from March 20 to June 20, 2006 The building under study is the new Concordia Sciences Building, located in Montreal, Quebec, Canada. The building has a total floor area of 32,000 m 2 (344,445 ft(2)), and mainly consists of research and academic labs. This paper presents the approach used to calibrate the model, the results of calibration, as well as problems encountered throughout the process from the user's perspective. The predictions of the supply and return air temperatures, the supply airflow rate, and the whole-building cooling loads, made by the EnergyPlus program over the spring season, are in agreement with monitored data.