This study assesses the performance gap between actual energy performance and desired energy performance outcomes for a case study of 19 LEED-certified multi-unit residential buildings in the Greater Toronto Area. The study examines 1) how accurately design-stage energy modelling predicts actual energy use, 2) how much variation of energy performance can be seen between buildings of the same level of certification, and 3) the key contributing factors of this performance gap. Using EUI as the basis of comparison, trend analysis was carried out. It was determined that a performance gap between modelled and actual building energy use does exist. When compared to a larger sample of existing buildings, the case study buildings show no real improvement, on average. Regression models revealed no strong correlation between LEED Level or LEED EAc1 credits and reduced EUIs.