This paper outlines a novel methodology for calibrating building energy simulation (BES) models through the use of an evidence-based approach and detailed simulation modelling. The proposed calibration methodology is applied to a 30,000m2 office building. The case study illustrates the results of calibrating the model to Energy Monitoring System (EMS) and other readily accessible data. The paper concludes with a discussion on the current state of calibrated BES modelling and building measurement frameworks.